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Sample records for radial slurry flow

  1. Turbulence in slurry pipe flow

    SciTech Connect

    Gore, R.A. ); Crowe, C.T. . Dept. of Mechanical and Materials Engineering)

    1990-01-01

    The present state of knowledge of liquid-solid flows (slurries) is far behind than that for single phase flows. Very few geometries have been examined with a slurry and only with a limited variation of system parameters i.e. fluid viscosity, particle diameter, etc. This paper presents the first part of a study which examines the effects of the addition of a solid to the flow through a confined coaxial jet. Presented here will be the initial conditions for the jet which correspond to fully developed pipe flow. 6 refs., 9 figs.

  2. Radial flow heat exchanger

    DOEpatents

    Valenzuela, Javier

    2001-01-01

    A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

  3. Radial flow pulse jet mixer

    DOEpatents

    VanOsdol, John G.

    2013-06-25

    The disclosure provides a pulse jet mixing vessel for mixing a plurality of solid particles. The pulse jet mixing vessel is comprised of a sludge basin, a flow surface surrounding the sludge basin, and a downcoming flow annulus between the flow surface and an inner shroud. The pulse jet mixing vessel is additionally comprised of an upper vessel pressurization volume in fluid communication with the downcoming flow annulus, and an inner shroud surge volume separated from the downcoming flow annulus by the inner shroud. When the solid particles are resting on the sludge basin and a fluid such as water is atop the particles and extending into the downcoming flow annulus and the inner shroud surge volume, mixing occurs by pressurization of the upper vessel pressurization volume, generating an inward radial flow over the flow surface and an upwash jet at the center of the sludge basin.

  4. Geotechnical properties of debris-flow sediments and slurries

    USGS Publications Warehouse

    Major, J.J.; Iverson, R.M.; McTigue, D.F.; Macias, S.; Fiedorowicz, B.K.

    1997-01-01

    Measurements of geotechnical properties of various poorly sorted debris-flow sediments and slurries (??? 32 mm diameter) emphasize their granular nature, and reveal that properties of slurries can differ significantly from those of compacted sediments. Measurements show that: (1) cohesion probably offers little resistance to shear in most debris flows under low confining stresses normally found in nature; (2) intrinsic hydraulic permeabilities of compacted debris-flow sediments vary from about 10-14-10-9 m2; permeabilities of 'typical' debris-flow slurries fall toward the low end of the range; (3) debris-flow slurries are characterized by very large values of 'elastic' compressibility (C approx. 10-2 kPa-1); and (4) hydraulic diffusivities of quasistatically consolidating slurries are approx. 10-4-10-7 m2/s. Low hydraulic diffusivity of debris slurries permits excess fluid pressure and low effective strength to persist during sediment transport and deposition.

  5. Solids flow rate measurement in dense slurries

    SciTech Connect

    Porges, K.G.; Doss, E.D.

    1993-09-01

    Accurate and rapid flow rate measurement of solids in dense slurries remains an unsolved technical problem, with important industrial applications in chemical processing plants and long-distance solids conveyance. In a hostile two-phase medium, such a measurement calls for two independent parameter determinations, both by non-intrusive means. Typically, dense slurries tend to flow in laminar, non-Newtonian mode, eliminating most conventional means that usually rely on calibration (which becomes more difficult and costly for high pressure and temperature media). These issues are reviewed, and specific solutions are recommended in this report. Detailed calculations that lead to improved measuring device designs are presented for both bulk density and average velocity measurements. Cross-correlation, chosen here for the latter task, has long been too inaccurate for practical applications. The cause and the cure of this deficiency are discussed using theory-supported modeling. Fluid Mechanics are used to develop the velocity profiles of laminar non-Newtonian flow in a rectangular duct. This geometry uniquely allows the design of highly accurate `capacitive` devices and also lends itself to gamma transmission densitometry on an absolute basis. An absolute readout, though of less accuracy, is also available from a capacitive densitometer and a pair of capacitive sensors yields signals suitable for cross-correlation velocity measurement.

  6. Slurry fired heater cold-flow modelling

    SciTech Connect

    Moujaes, S.F.

    1983-07-01

    This report summarizes the experimental and theoretical work leading to the scale-up of the SRC-I Demonstration Plant slurry fired heater. The scale-up involved a theoretical model using empirical relations in the derivation, and employed variables such as flow conditions, liquid viscosity, and slug frequency. Such variables have been shown to affect the heat transfer characteristics ofthe system. The model assumes that, if all other variables remain constant, the heat transfer coefficient can be scaled up proportional to D/sup -2/3/ (D = inside diameter of the fired heater tube). All flow conditions, liquid viscosities, and pipe inclinations relevant to the demonstration plant have indicated a slug flow regime in the slurry fired heater. The annular and stratified flow regimes should be avoided to minimize the potential for excessive pipe erosion and to decrease temperature gradients along the pipe cross section leading to coking and thermal stresses, respectively. Cold-flow studies in 3- and 6.75-in.-inside-diameter (ID) pipes were conducted to determine the effect of scale-up on flow regime, slug frequency, and slug dimensions. The developed model assumes that conduction heat transfer occurs through the liquid film surrounding the gas slug and laminar convective heat transfer to the liquid slug. A weighted average of these two heat transfer mechanisms gives a value for the average pipe heat transfer coefficient. The cold-flow work showed a decrease in the observed slug frequency between the 3- and 6.75-ID pipes. Data on the ratio of gas to liquid slug length in the 6.75-in. pipe are not yet complete, but are expected to yield generally lower values than those obtained in the 3-in. pipe; this will probably affect the scale-up to demonstration plant conditions. 5 references, 15 figures, 7 tables.

  7. Fluid mechanics of slurry flow through the grinding media in ball mills

    SciTech Connect

    Songfack, P.K.; Rajamani, R.K.

    1995-12-31

    The slurry transport within the ball mill greatly influences the mill holdup, residence time, breakage rate, and hence the power draw and the particle size distribution of the mill product. However, residence-time distribution and holdup in industrial mills could not be predicted a priori. Indeed, it is impossible to determine the slurry loading in continuously operating mills by direct measurement, especially in industrial mills. In this paper, the slurry transport problem is solved using the principles of fluid mechanics. First, the motion of the ball charge and its expansion are predicted by a technique called discrete element method. Then the slurry flow through the porous ball charge is tackled with a fluid-flow technique called the marker and cell method. This may be the only numerical technique capable of tracking the slurry free surface as it fluctuates with the motion of the ball charge. The result is a prediction of the slurry profile in both the radial and axial directions. Hence, it leads to the detailed description of slurry mass and ball charge within the mill. The model predictions are verified with pilot-scale experimental work. This novel approach based on the physics of fluid flow is devoid of any empiricism. It is shown that the holdup of industrial mills at a given feed percent solids can be predicted successfully.

  8. Waste Slurry Particle Properties for Use in Slurry Flow Modeling

    SciTech Connect

    Jewett, J. R.; Conrads, T. J.; Julyk, L. J.; Reynolds, D. A.; Jensen, L.; Kirch, N. W.; Estey, S. D.; Bechtold, D. B.; Callaway III, W. S.; Cooke, G. A.; Herting, D. L.; Person, J. C.; Duncan, J. B.; Onishi, Y.; Tingey, J. M.

    2003-02-26

    Hanford's tank farm piping system must be substantially modified to deliver high-level wastes from the underground storage tanks to the Waste Treatment Plant now under construction. Improved knowledge of the physical properties of the solids was required to support the design of the modified system. To provide this additional knowledge, particle size distributions for composite samples from seven high-level waste feed tanks were measured using two different laser lightscattering particle size analyzers. These measurements were made under a variety of instrumental conditions, including various flow rates through the sample loop, various stirring rates in the sample reservoir, and before and after subjecting the particles to ultrasonic energy. A mean value over all the tanks of 4.2 {micro}m was obtained for the volume-based median particle size. Additional particle size information was obtained from sieving tests, settling tests and microscopic observations.

  9. Stirling Engine With Radial Flow Heat Exchangers

    NASA Technical Reports Server (NTRS)

    Vitale, N.; Yarr, George

    1993-01-01

    Conflict between thermodynamical and structural requirements resolved. In Stirling engine of new cylindrical configuration, regenerator and acceptor and rejector heat exchangers channel flow of working gas in radial direction. Isotherms in regenerator ideally concentric cylinders, and gradient of temperature across regenerator radial rather than axial. Acceptor and rejector heat exchangers located radially inward and outward of regenerator, respectively. Enables substantial increase in power of engine without corresponding increase in diameter of pressure vessel.

  10. Slurry

    NASA Astrophysics Data System (ADS)

    Jiang, Ting; Lei, Hong

    2014-11-01

    With magnetic heads operating closer to hard disks, the hard disks must be ultra-smooth. The abrasive-free polishing (AFP) performance of cumene hydroperoxide (CHP) as the initiator in H2O2-based slurry for hard disk substrate was investigated in our work, and the results showed that the slurry including CHP could improve the material removal rate (MRR) and also reduce surface roughness. Electron spin-resonance spectroscopy (EPR), electrochemical measurement and Auger electron spectroscopy (AES) were conducted to investigate the acting mechanism with CHP during the polishing process. Compared with the H2O2 slurry, the EPR analysis shows that the CHP-H2O2 slurry provides a higher concentration of the HOO free radical. In addition, the AES analysis shows the oxidization reaction occurs in the external layer of the substrate surface. Furthermore, electrochemical measurements reveal that CHP can promote the electrochemical effect in AFP and lead to the increase of MRR.

  11. Study of unsteady flow conditions for slurry fuels

    SciTech Connect

    Ekmann, J.M.; Wildman, D.J.; Klinzing, G.E.

    1985-01-01

    During the past three years, transport characteristics of coal-water mixtures (CWMs) have been studied at the Pittsburgh Energy Technology Center. The effort has concentrated predominantly on studying flow conditions in straight horizontal and vertical sections, and to a lesser extent on studying the flow patterns around elbows of a one-inch-diameter loop and a two-inch-diameter loop. Steady-state flow was characterized for in-house prepared slurries and commercially prepared slurries. For lower concentrated slurries (55 wt % to 60 wt %) and coarse particle size distributions (50% finer than 75 microns), nonhomogeneous flow conditions were encountered across horizontal test sections. Since nonhomogeneous conditions existed in straight sections during steady-state flow, it was decided to further investigate flow conditions during changes in velocity (magnitude and direction). This paper concentrates on nonuniform flow conditions of two types. The first nonuniform flow condition arises from sudden increases in the magnitude of the flow velocity. Pressure measurements recorded at a fixed position in the vertical section of the two-inch-diameter loop during sudden changes in velocity can be analyzed via classic control theory to evaluate the dynamic properties of the CWM. The second nonuniform flow condition occurs as the CWM passes through a bend. Both long-radius bends and 90-degree elbows made of glass and steel have been studied. Pressure-loss data around the long-radius bends and elbows were analyzed with a modified version of the model developed by Ito for single-phase flow around bends. Flow patterns around glass bends and elbows were observed for slurries prepared of vinyl coating powder and water. They are described in an effort to increase understanding of the pressure-loss data. 8 refs., 11 figs., 1 tab.

  12. Radial flow nuclear thermal rocket (RFNTR)

    DOEpatents

    Leyse, Carl F.

    1995-01-01

    A radial flow nuclear thermal rocket fuel assembly includes a substantially conical fuel element having an inlet side and an outlet side. An annular channel is disposed in the element for receiving a nuclear propellant, and a second, conical, channel is disposed in the element for discharging the propellant. The first channel is located radially outward from the second channel, and separated from the second channel by an annular fuel bed volume. This fuel bed volume can include a packed bed of loose fuel beads confined by a cold porous inlet frit and a hot porous exit frit. The loose fuel beads include ZrC coated ZrC-UC beads. In this manner, nuclear propellant enters the fuel assembly axially into the first channel at the inlet side of the element, flows axially across the fuel bed volume, and is discharged from the assembly by flowing radially outward from the second channel at the outlet side of the element.

  13. Radial flow nuclear thermal rocket (RFNTR)

    DOEpatents

    Leyse, Carl F.

    1995-11-07

    A radial flow nuclear thermal rocket fuel assembly includes a substantially conical fuel element having an inlet side and an outlet side. An annular channel is disposed in the element for receiving a nuclear propellant, and a second, conical, channel is disposed in the element for discharging the propellant. The first channel is located radially outward from the second channel, and separated from the second channel by an annular fuel bed volume. This fuel bed volume can include a packed bed of loose fuel beads confined by a cold porous inlet frit and a hot porous exit frit. The loose fuel beads include ZrC coated ZrC-UC beads. In this manner, nuclear propellant enters the fuel assembly axially into the first channel at the inlet side of the element, flows axially across the fuel bed volume, and is discharged from the assembly by flowing radially outward from the second channel at the outlet side of the element.

  14. Flow of Slurry in the Inclined Closed Channel

    NASA Astrophysics Data System (ADS)

    Ashrafi Khorasani, Nariman; Piroozram, Parastoo

    2015-11-01

    The flow of slurry in a closed inclined circular channel is examined. The viscoelastic fluid is modeled as a derivative of typical Oldroyd-B relation of stress and velocity gradient. First, gravity is considered as the driving force for the fluid flow to simulate the existing sewage system. The complete flow field is evaluated for this case. Next, a pressure gradient is introduced to observe its effects on the flow. Velocity profile as well as stress distributions are given for different scenarios of the nonlinear fluid flowing in a closed channel with and without pressure gradient.

  15. Flow resistance of ice slurry in bends and elbow pipes

    NASA Astrophysics Data System (ADS)

    Niezgoda-Żelasko, B.; Żelasko, J.

    2014-08-01

    The present paper covers the flow of ice slurry made of a 10.6% ethanol solution through small-radius bends and elbow pipes. The paper presents the results of experimental research on the flow resistances of Bingham-fluid ice slurry in bends and elbows. The research, performed for three pipe diameters and a relative bend radius of 1<=D/di<=2, has made it possible to take into consideration the influence of friction resistances as well the of the flow geometry on the total local resistance coefficients. The study attempts to make the local resistance coefficient dependent on the Dean number defined for a generalized Reynolds number according to Metzner-Reade

  16. Modeling flow and sedimention of slurries

    NASA Astrophysics Data System (ADS)

    Mondy, L.; Rao, R.; Altobelli, S.; Ingber, M.; Graham, A.

    2002-12-01

    Many natural processes involve flows of sediments at high particle concentrations. The equations describing such two-phase flows are highly nonlinear. We will give an overview of the performance of a continuum constitutive model of suspensions of particles in liquid for low Reynolds number flows. The diffusive flux model (Leighton and Acrivos, J. Fluid Mech., 1987, and Phillips et al., Phys. Fluids A, 1992) is implemented in a general purpose finite element computational program. This constitutive description couples a Newtonian stress/shear-rate relationship (where the local viscosity of the suspension is dependent on the local volume fraction of solids) with a shear-induced migration model of the suspended particles. The momentum transport, continuity, and diffusive flux equations are solved simultaneously. The formulation is fully three-dimensional and can be run on a parallel computer platform. Recent work introducing a flow-aligned tensor correction to this model has had success in representing the anisotropic force that is seen in curvilinear flows. Gravity effects are added in an approach similar to that of Zhang and Acrivos (Int. J. Multiphase Flow, 1994). The model results are compared with laboratory data obtained with Nuclear Magnetic Resonance (NMR) of evolving particle concentration profiles in complex flows, as well as in batch sedimentation. Interesting secondary flows appear both in the experiment and model. Overall, good agreement is found between the experiments and the simulations. This work was supported by the United States Department of Energy under Contract DE-AC04- 94AL85000. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy. The authors would like to acknowledge support for this work by the U.S. Department of Energy, Division of Engineering and Geosciences, Office of Basic Energy Sciences.

  17. Fast radial flows in transition disk holes

    SciTech Connect

    Rosenfeld, Katherine A.; Andrews, Sean M.; Chiang, Eugene

    2014-02-20

    Protoplanetary 'transition' disks have large, mass-depleted central cavities, yet also deliver gas onto their host stars at rates comparable to disks without holes. The paradox of simultaneous transparency and accretion can be explained if gas flows inward at much higher radial speeds inside the cavity than outside the cavity, since surface density (and by extension optical depth) varies inversely with inflow velocity at fixed accretion rate. Radial speeds within the cavity might even have to approach free-fall values to explain the huge surface density contrasts inferred for transition disks. We identify observational diagnostics of fast radial inflow in channel maps made in optically thick spectral lines. Signatures include (1) twisted isophotes in maps made at low systemic velocities and (2) rotation of structures observed between maps made in high-velocity line wings. As a test case, we apply our new diagnostic tools to archival Atacama Large Millimeter Array data on the transition disk HD 142527 and uncover evidence for free-fall radial velocities inside its cavity. Although the observed kinematics are also consistent with a disk warp, the radial inflow scenario is preferred because it predicts low surface densities that appear consistent with recent observations of optically thin CO isotopologues in this disk. How material in the disk cavity sheds its angular momentum wholesale to fall freely onto the star is an unsolved problem; gravitational torques exerted by giant planets or brown dwarfs are briefly discussed as a candidate mechanism.

  18. Technical Report on NETL's Non Newtonian Multiphase Slurry Workshop: A path forward to understanding non-Newtonian multiphase slurry flows

    SciTech Connect

    Edited by Guenther, Chris; Garg, Rahul

    2013-08-19

    The Department of Energy’s (DOE) National Energy Technology Laboratory (NETL) sponsored a workshop on non-Newtonian multiphase slurry at NETL’s Morgantown campus August 19 and 20, 2013. The objective of this special two-day meeting of 20-30 invited experts from industry, National Labs and academia was to identify and address technical issues associated with handling non-Newtonian multiphase slurries across various facilities managed by DOE. Particular emphasis during this workshop was placed on applications managed by the Office of Environmental Management (EM). The workshop was preceded by two webinars wherein personnel from ORP and NETL provided background information on the Hanford WTP project and discussed the critical design challenges facing this project. In non-Newtonian fluids, viscosity is not constant and exhibits a complex dependence on applied shear stress or deformation. Many applications under EM’s tank farm mission involve non-Newtonian slurries that are multiphase in nature; tank farm storage and handling, slurry transport, and mixing all involve multiphase flow dynamics, which require an improved understanding of the mechanisms responsible for rheological changes in non-Newtonian multiphase slurries (NNMS). To discuss the issues in predicting the behavior of NNMS, the workshop focused on two topic areas: (1) State-of-the-art in non-Newtonian Multiphase Slurry Flow, and (2) Scaling up with Confidence and Ensuring Safe and Reliable Long-Term Operation.

  19. Radial slot flows in solid rocket motors

    NASA Astrophysics Data System (ADS)

    Hilbing, J. H.; Heister, S. D.

    1993-06-01

    A series of parametric numerical solutions have been generated to characterize the two-dimensional flowfield due to the presence of a radial slot in a solid rocket propellant grain. Results have been parameterized in terms of upstream core Mach number, slot contraction ratio, and slot-to-core mass flow and momentum ratios. Numerical solutions of the axisymmetric Euler equations have been obtained on a 'generic' slot geometry using a cell-centered, finite volume scheme. Results indicate that both the stagnation pressure loss and grain suction force on the propellant segment downstream of the slot correlate well with slot-to-core momentum ratio; a parameter which has not been used in previous studies. Significant differences (in stagnation pressure losses) have been identified between the 2-D numerical results and the 1-D methods applied in current state-of-the-art ballistics codes. We anticipate that the correlations derived through this parametric study can be used in preliminary performance and grain stress analyses performed during the motor development process.

  20. Flow velocity analysis for avoidance of solids deposition during transport of Hanford tank waste slurries

    SciTech Connect

    ESTEY, S.D.

    1999-02-25

    This engineering analysis calculates minimum slurry transport velocities intended to maintain suspensions of solid particulate in slurries. This transport velocity is also known as the slurry flow critical velocity. It is not universally recognized that a transfer line flow velocity in excess of the slurry critical velocity is a requirement to prevent solids deposition and possible line plugging. However, slurry critical velocity seems to be the most prevalent objective measure to prevent solids deposition in transfer lines. The following critical velocity correlations from the literature are investigated: Durand (1953), Spells (1955), Sinclair (1962), Zandi and Gavatos (1967), Babcock (1968), Shook (1969), and Oroskar and Turian (1980). The advantage of these critical velocity correlations is that their use is not reliant upon any measure of bulk slurry viscosity. The input parameters are limited to slurry phase densities and mass fractions, pipe diameter, particle diameter, and viscosity of the pure liquid phase of the slurry. Consequently, the critical velocity calculation does not require determination of system pressure drops. Generalized slurry properties can, therefore, be recommended if the slurry can be adequately described by these variables and if the liquid phase viscosity is known. Analysis of these correlations are presented, indicating that the Oroskar and Turian (1980) models appear to be more conservative for smaller particulate sizes, typically those less than 100 microns diameter. This analysis suggests that the current Tank Farms waste compatibility program criteria may be insufficient to prevent particulate solids settling within slurry composition ranges currently allowed by the waste compatibility program. However, in order to relate a critical velocity associated with a certain slurry composition to a system limit, a means of relating the system capabilities to the slurry composition must be found. Generally, this means expressing the bulk

  1. Characterization of Flow Behavior of Semi-Solid Slurries with Low Solid Fractions

    NASA Astrophysics Data System (ADS)

    Chucheep, Thiensak; Wannasin, Jessada; Canyook, Rungsinee; Rattanochaikul, Tanate; Janudom, Somjai; Wisutmethangoon, Sirikul; Flemings, Merton C.

    2013-10-01

    Semi-solid slurry casting is a metal-forming process that involves transforming liquid metal into slurry having a low solid fraction and then forming the slurry into solid parts. To successfully apply this slurry-forming process, it is necessary to fully understand the flow behavior of semi-solid slurries. This present work applied the rapid quenching method and the modified gravity fluidity casting to investigate the flow behavior, which involves characterizations of the initial solid fraction, fluidity, and microstructure of semi-solid slurries. Three commercial aluminum alloys were used in this study: 383 (Al-Si11Cu), 356 (Al-Si7MgFe), and 7075 (Al-Zn6MgCu) alloys. The results show that the initial solid fractions can be controlled by varying the rheocasting time. The rapid quenching mold can be used to determine the initial solid fractions. In this method, it is important to apply the correcting procedure to account for growth during quenching and to include all the solid phases. Results from the fluidity study of semi-solid slurries show that the fluidity decreases as the initial solid fraction increases. The decrease is relatively rapid near the low end of the initial solid fraction curves, but is quite slow near the high end of the curves. All the three alloys follow this trend. The results also demonstrate that the slurries that contain high solid fractions of up to 30 pct can still flow well. The microstructure characterization results show that the solid particles in the slurries flow uniformly in the channel. A uniform and fine microstructure with limited phase segregation is observed in the slurry cast samples.

  2. Radial flow afterburner for event generators and the baryon puzzle

    NASA Astrophysics Data System (ADS)

    Cuautle, E.; Paic, G.

    2008-07-01

    A simple afterburner to add radial flow to the randomized transverse momentum obtained from event generators, PYTHIA and HIJING, has been implemented to calculate the p/π ratios and compare them with available data. A coherent trend of qualitative agreement has been obtained in pp and Au+Au collisions for various centralities. These results indicate that the radial flow does play an important role in the so-called baryon puzzle anomaly.

  3. Low cost, radial flow, solid oxide fuel cell

    SciTech Connect

    Petrik, M.A.

    1993-11-01

    The Interscience Radial Flow (IRF) SOFC is designed to minimize problems in high-temperature operation, and for low-cost fabrication. The cell has planar, non-sintered construction, uses particulate materials to form porous electrodes, and has internal radial flow. This phase was to demonstrate feasibility of multi-cell stack operation. Performance milestone was 15% DC HHV efficiency with hydrogen at > 50 mW/cm{sup 2} over 100 h.

  4. Dynamics of a vortex pair in radial flow

    SciTech Connect

    Bannikova, E. Yu. Kontorovich, V. M. Reznik, G. M.

    2007-10-15

    The problem of vortex pair motion in two-dimensional radial flow is solved. Under certain conditions for flow parameters, the vortex pair can reverse its motion within a bounded region. The vortex-pair translational velocity decreases or increases after passing through the source/sink region, depending on whether the flow is diverging or converging, respectively. The rotational motion of a corotating vortex pair in a quiescent environment transforms into motion along a logarithmic spiral in radial flow. The problem may have applications in astrophysics and geophysics.

  5. The effect of particle-particle interaction forces on the flow properties of silica slurries

    SciTech Connect

    Harbottle, David; Fairweather, Michael; Biggs, Simon; Rhodes, Dominic

    2007-07-01

    Preliminary work has been completed to investigate the effect of particle-particle interaction forces on the flow properties of silica slurries. Classically hydro-transport studies have focused on the flow of coarse granular material in Newtonian fluids. However, with current economical and environmental pressures, the need to increase solid loadings in pipe flow has lead to studies that examine non-Newtonian fluid dynamics. The flow characteristics of non-Newtonian slurries can be greatly influenced through controlling the solution chemistry. Here we present data on an 'ideal' slurry where the particle size and shape is controlled together with the solution chemistry. We have investigated the effect of adsorbed cations on the stability of a suspension, the packing nature of a sediment and the frictional forces to be overcome during re-slurrying. A significant change in the criteria assessed was observed as the electrolyte concentration was increased from 0.1 mM to 1 M. In relation to industrial processes, such delicate control of the slurry chemistry can greatly influence the optimum operating conditions of non-Newtonian pipe flows. (authors)

  6. Effect of the radial buoyancy on a circular Couette flow

    NASA Astrophysics Data System (ADS)

    Meyer, Antoine; Yoshikawa, Harunori N.; Mutabazi, Innocent

    2015-11-01

    The effect of a radial temperature gradient on the stability of a circular Couette flow is investigated when the gravitational acceleration is neglected. The induced radial stratification of the fluid density coupled with the centrifugal acceleration generates radial buoyancy which is centrifugal for inward heating and centripetal for outward heating. This radial buoyancy modifies the Rayleigh discriminant and induces the asymmetry between inward heating and outward heating in flow behavior. The critical modes are axisymmetric and stationary for inward heating while for outward heating, they can be oscillatory axisymmetric or nonaxisymmetric depending on fluid diffusion properties, i.e., on the Prandtl number Pr. The dependence of the critical modes on Pr is explored for different values of the radius ratio of the annulus. The power input of the radial buoyancy is compared with other power terms. The critical frequency of the oscillatory axisymmetric modes is linked to the Brunt-Väisälä frequency due to the density stratification in the radial gravity field induced by the rotation. These modes are associated with inertial waves. The dispersion relation of the oscillatory axisymmetric modes is derived in the vicinity of the critical conditions. A weakly nonlinear amplitude equation with a forcing term is proposed to explain the domination of these axisymmetric oscillatory modes over the stationary centrifugal mode.

  7. Self-sustained radial oscillating flows between parallel disks

    NASA Astrophysics Data System (ADS)

    Mochizuki, S.; Yang, W.-J.

    1985-05-01

    It is pointed out that radial flow between parallel circular disks is of interest in a number of physical systems such as hydrostatic air bearings, radial diffusers, and VTOL aircraft with centrally located downward-positioned jets. The present investigation is concerned with the problem of instability in radial flow between parallel disks. A time-dependent numerical study and experiments are conducted. Both approaches reveal the nucleation, growth, migration, and decay of annular separation bubbles (i.e. vortex or recirculation zones) in the laminar-flow region. A finite-difference technique is utilized to solve the full unsteady vorticity transport equation in the theoretical procedure, while the flow patterns in the experiments are visualized with the aid of dye-injection, hydrogen-bubble, and paraffin-mist methods. It is found that the separation and reattachment of shear layers in the radial flow through parallel disks are unsteady phenomena. The sequence of nucleation, growth, migration, and decay of the vortices is self-sustained.

  8. Longitudinal Dispersivity in a Radial Diverging Flow Field

    NASA Astrophysics Data System (ADS)

    Seaman, J. C.; Wilson, M.; Bertsch, P. M.; Aburime, S. A.

    2005-12-01

    Hydrodynamic dispersion is an important factor controlling contaminant migration in the subsurface environment. However, few comprehensive data sets exist for evaluating the impact of travel distance and site heterogeneity on solute dispersion under non-uniform flow conditions. In addition, anionic tracers are often used to estimate physical transport parameters based on an erroneous assumption of conservative (i.e., non-reactive) behavior. Therefore, a series of field experiments using tritiated water and several other commonly used hydrologic tracers (Br, Cl, FBAs) were conducted in the water-table aquifer on the U.S. Department of Energy's Savannah River Site (Aiken, SC) to evaluate solute transport processes in a diverging radial flow field. For each experiment, tracer-free groundwater was injected for approximately 24 hours at a fixed rate of 56.7 L/min (15 gpm) to establish a forced radial gradient prior to the introduction of a tracer pulse. After the tracer pulse, the forced gradient was maintained throughout the experiment using non-labeled groundwater. Tracer migration was monitored using a set of six sampling wells radially spaced at approximate distances of 1.5, 3, and 4.5 meters from a central injection well. Each sampling well was further divided into three discrete sampling depths that were monitored continuously throughout the course of the tracer experiment. At various time intervals, discrete groundwater samples were collected from all 18 sampling ports for tritium analysis. Longitudinal dispersivity for tritium breakthrough at each sampling location was estimated using analytical approximations of the convection dispersion equation (CDE) for radial flow assuming an instantaneous Dirac pulse and a pulse of known duration. The results were also compared to dispersivity values derived from fitting the tracer data to analytical solutions derived from assuming uniform flow conditions. Tremendous variation in dispersivity values and tracer arrival

  9. Flow of Magnetohydrodynamic Micropolar Fluid Induced by Radially Stretching Sheets

    NASA Astrophysics Data System (ADS)

    Hayat, Tasawar; Nawaz, Muhammad; Hendi, Awatif A.

    2011-02-01

    We investigate the flow of a micropolar fluid between radial stretching sheets. The magnetohydrodynamic (MHD) nonlinear problem is treated using the homotopy analysis method (HAM) and the velocity profiles are predicted for the pertinent parameters. The values of skin friction and couple shear stress coefficients are obtained for various values of Reynolds number, Hartman number, and micropolar fluid parameter.

  10. Radial Plasma Flow Switch on GIT-12 Generator

    NASA Astrophysics Data System (ADS)

    Chaikovsky, S. A.; Kokshenev, V. A.; Rousskikh, A. G.; Shishlov, A. V.; Fedunin, A. V.; Labetsky, A. Yu.; Kurmaev, N. E.; Fursov, F. I.

    2006-01-01

    The preliminary experiments were performed on wire array implosion driven by a radial plasma flow switch on the GIT-12 generator operating in a microsecond mode. Imploding gas puff z-pinch plasma was used to provide fast switching of the current to an aluminum wire array. The experimental results are presented in the paper.

  11. Linear stability of radially-heated circular Couette flow with simulated radial gravity

    NASA Astrophysics Data System (ADS)

    Tagg, Randy; Weidman, Patrick D.

    2007-05-01

    The stability of circular Couette flow between vertical concentric cylinders in the presence of a radial temperature gradient is considered with an effective “radial gravity.” In addition to terrestrial buoyancy - ρg e z we include the term - ρg m f(r)e r where g m f(r) is the effective gravitational acceleration directed radially inward across the gap. Physically, this body force arises in experiments using ferrofluid in the annular gap of a Taylor Couette cell whose inner cylinder surrounds a vertical stack of equally spaced disk magnets. The radial dependence f(r) of this force is proportional to the modified Bessel function K 1(κr), where 2π/κ is the spatial period of the magnetic stack and r is the radial coordinate. Linear stability calculations made to compare with conditions reported by Ali and Weidman (J. Fluid Mech., 220, 1990) show strong destabilization effects, measured by the onset Rayleigh number R, when the inner wall is warmer, and strong stabilization effects when the outer wall is warmer, with increasing values of the dimensionless radial gravity γ = g m /g. Further calculations presented for the geometry and fluid properties of a terrestrial laboratory experiment reveal a hitherto unappreciated structure of the stability problem for differentially-heated cylinders: multiple wavenumber minima exist in the marginal stability curves. Transitions in global minima among these curves give rise to a competition between differing instabilities of the same spiral mode number, but widely separated axial wavenumbers.

  12. Experimental investigation of ice slurry flow pressure drop in horizontal tubes

    SciTech Connect

    Grozdek, Marino; Khodabandeh, Rahmatollah; Lundqvist, Per

    2009-01-15

    Pressure drop behaviour of ice slurry based on ethanol-water mixture in circular horizontal tubes has been experimentally investigated. The secondary fluid was prepared by mixing ethyl alcohol and water to obtain initial alcohol concentration of 10.3% (initial freezing temperature -4.4 C). The pressure drop tests were conducted to cover laminar and slightly turbulent flow with ice mass fraction varying from 0% to 30% depending on test conditions. Results from flow tests reveal much higher pressure drop for higher ice concentrations and higher velocities in comparison to the single phase flow. However for ice concentrations of 15% and higher, certain velocity exists at which ice slurry pressure drop is same or even lower than for single phase flow. It seems that higher ice concentration delay flow pattern transition moment (from laminar to turbulent) toward higher velocities. In addition experimental results for pressure drop were compared to the analytical results, based on Poiseulle and Buckingham-Reiner models for laminar flow, Blasius, Darby and Melson, Dodge and Metzner, Steffe and Tomita for turbulent region and general correlation of Kitanovski which is valid for both flow regimes. For laminar flow and low buoyancy numbers Buckingham-Reiner method gives good agreement with experimental results while for turbulent flow best fit is provided with Dodge-Metzner and Tomita methods. Furthermore, for transport purposes it has been shown that ice mass fraction of 20% offers best ratio of ice slurry transport capability and required pumping power. (author)

  13. Instrumentation to Monitor Transient Periodic Developing Flow in Non-Newtonian Slurries

    SciTech Connect

    Bamberger, Judith A.; Enderlin, Carl W.

    2013-11-15

    Staff at Pacific Northwest National Laboratory have conducted mixing and mobilization experiments with non-Newtonian slurries that exhibit Bingham plastic and shear thinning behavior and shear strength. This paper describes measurement techniques applied to identify the interface between flowing and stationary regions of non-Newtonian slurries that are subjected to transient, periodic, developing flows. Techniques were developed to identify the boundary between the flowing and stationary regions, time to mix, characteristic velocities of the flow field produced by the symmetrically spaced nozzles, and the velocity of the upwell formed in the center of the tank by the intersection of flow from four symmetrically spaced nozzles that impinge upon the tank floor. Descriptions of the instruments and instrument performance are presented. These techniques were an effective approach to characterize mixing phenomena, determine mixing energy required to fully mobilize vessel contents and to determine mixing times for process evaluation.

  14. Analysis and performance of radial flow rotary dessicant dehumidifiers

    SciTech Connect

    Elsayed, M.M.; Chamkha, A.J.

    1997-02-01

    A model is developed to predict the steady periodic performance of a radial flow desiccant wheel. The model is expressed in terms of the same dimensionless parameters that are commonly used in modeling of the conventional axial flow desiccant wheel. In addition a dimensionless geometrical ratio of the volume of the matrix to the volume of the wheel core is found to affect the performance of the wheel. A finite difference technique on staggered grid is used to discretize the governing dimensionless equations. The discretized equations are solved to predict the performance of the desiccant wheel at given values of operation parameters. A sensitivity study is carried out to investigate the effect of changing any of these parameters on the performance of the wheel. The performance of the radial flow desiccant wheel having the same values of the operation parameters.

  15. Non-radial flow in the solar wind

    NASA Technical Reports Server (NTRS)

    Richardson, J. D.; Paularena, K. I.; Gazis, P. R.

    1995-01-01

    Although the radial component of the solar wind dominates the solar wind speed, significant non-radial velocity components are also present. These flows are more difficult to measure accurately, but we now have data sets including the east-west (tangential) and north-south (normal) flows from PVO at Venus, IMP 8 at Earth, and Voyagers 1 and 2 from 1 to 45 AU. We compare the non-radial flow observations from these spacecraft. One of the more interesting features is that the north-south flow angle observed at Earth and Venus oscillates with the period of a local (Earth or Venus) year. These oscillations occur throughout two solar cycles in the IMP 8 data set and are very apparent in the PVO data from 1978 to 1986 but less obvious after this. We will report on the origin of this feature. The tangential flow observed by both IMP 8 and Voyager is on average slightly positive (approximately 1.75 km/s). The magnitudes of the nonradial velocity components decrease with distance from the Sun.

  16. Transport of veterinary antibiotics in overland flow following the application of slurry to arable land.

    PubMed

    Kay, Paul; Blackwell, Paul A; Boxall, Alistair B A

    2005-05-01

    The environment may be exposed to veterinary medicines administered to livestock due to the application of organic fertilisers to land. Slurry is often spread on to fields following the harvest of the previous crop. Despite recommendations to do so, the slurry may not be ploughed into the soil for some time. If precipitation occurs before incorporation then it is likely that the slurry and any antibiotic residues in the slurry will be transported towards surface waters in overland flow. This phenomenon has been investigated in a plot study and transport via 'tramlines' has been compared to that through crop stubble. Three veterinary antibiotics, from the tetracycline, sulphonamide and macrolide groups, were applied to the plots in pig slurry. Twenty four hours after the application the plots were irrigated. Following this the plots received natural rainfall. Sulphachloropyridazine was detected in runoff from the tramline plot at a peak concentration of 703.2 microgl(-1) and oxytetracycline at 71.7 microgl(-1). Peak concentrations from the plot that did not contain a tramline were lower at 415.5 and 32 microgl(-1), respectively. In contrast, tylosin was not detected at all. Mass losses of the compounds were also greater from the tramline plot due to greater runoff generation. These did not exceed 0.42% for sulphachloropyridazine and 0.07% for oxytetracycline however. PMID:15823328

  17. FUEL SUBASSEMBLY CONSTRUCTION FOR RADIAL FLOW IN A NUCLEAR REACTOR

    DOEpatents

    Treshow, M.

    1962-12-25

    An assembly of fuel elements for a boiling water reactor arranged for radial flow of the coolant is described. The ingress for the coolant is through a central header tube, perforated with parallel circumferertial rows of openings each having a lip to direct the coolant flow downward. Around the central tube there are a number of equally spaced concentric trays, closely fitiing the central header tube. Cylindrical fuel elements are placed in a regular pattern around the central tube, piercing the trays. A larger tube encloses the arrangement, with space provided for upward flow of coolart beyond the edge of the trays. (AEC)

  18. Evaluation of Computational Method of High Reynolds Number Slurry Flow for Caverns Backfilling

    SciTech Connect

    Bettin, Giorgia

    2015-05-01

    The abandonment of salt caverns used for brining or product storage poses a significant environmental and economic risk. Risk mitigation can in part be address ed by the process of backfilling which can improve the cavern geomechanical stability and reduce the risk o f fluid loss to the environment. This study evaluate s a currently available computational tool , Barracuda, to simulate such process es as slurry flow at high Reynolds number with high particle loading . Using Barracuda software, a parametric sequence of simu lations evaluated slurry flow at Re ynolds number up to 15000 and loading up to 25%. Li mitations come into the long time required to run these simulation s due in particular to the mesh size requirement at the jet nozzle. This study has found that slurry - jet width and centerline velocities are functions of Re ynold s number and volume fractio n The solid phase was found to spread less than the water - phase with a spreading rate smaller than 1 , dependent on the volume fraction. Particle size distribution does seem to have a large influence on the jet flow development. This study constitutes a first step to understand the behavior of highly loaded slurries and their ultimate application to cavern backfilling.

  19. Measurements of pressure drop and heat transfer in turbulent pipe flows of particulate slurries

    NASA Astrophysics Data System (ADS)

    Liu, K. V.; Choi, U. S.; Kasza, K. E.

    1988-05-01

    Argonne National Laboratory (ANL), under sponsorhip of DOE, Office of Buildings and Community Systems, has been conducting a comprehensive, long-range program to develop high-performance advanced energy transmission fluids for use in district heating and cooling (DHC) systems. The current study focuses on the development of phase-change slurries as advanced energy transmission fluids. The objectives are: (1) to establish proof-of-concept of enhanced heat transfer by a slurry, with and without phase change, relative to heat transfer in a pure carrier liquid; (2) to investigate the effect of particle volumetric loading, size, and flow rate on the slurry pressure drip and heat transfer behavior with and without friction-reducing additives; and (3) to generate pressure drop and heat transfer data needed for the development and design of improved DHC systems. Two types of phase-change materials were used in the experiments: ice slush for cooling, and cross-linked, high- density polyethylene (X-HDPE) particles with diameters of 1/8 and 1/20 in. (3.2 and 1.3 mm) for heating. The friction-reducing additive used in the tests was Separan AP-272 at 65 wppm. This report describes the test facility, discusses the experimental procedures, and presents significant experimental results on flow and heat transfer characteristics of the non-melting slurry flows.

  20. Study of Cold Heat Energy Release Characteristics of Flowing Ice Water Slurry in a Pipe

    NASA Astrophysics Data System (ADS)

    Inaba, Hideo; Horibe, Akihiko; Ozaki, Koichi; Yokota, Maki

    This paper has dealt with melting heat transfer characteristics of ice water slurry in an inside tube of horizontal double tube heat exchanger in which a hot water circulated in an annular gap between the inside and outside tubes. Two kinds of heat exchangers were used; one is made of acrylic resin tube for flow visualization and the other is made of stainless steel tube for melting heat transfer measurement. The result of flow visualization revealed that ice particles flowed along the top of inside tube in the ranges of small ice packing factor and low ice water slurry velocity, while ice particles diffused into the whole of tube and flowed like a plug built up by ice particles for large ice packing factor and high velocity. Moreover, it was found that the flowing ice plug was separated into numbers of small ice clusters by melting phenomenon. Experiments of melting heat transfer were carried out under some parameters of ice packing factor, ice water slurry flow rate and hot water temperature. Consequently, the correlation equation of melting heat transfer was derived as a function of those experimental parameters.

  1. Confirmation test for gas/slurry flow in SRC-I coal liquefaction process. Internal R and D final report

    SciTech Connect

    Moujaes, S.F.

    1983-09-01

    The overall objective of program 12.11.1 was to provide data needed to confirm the design of the transport system, slurry heat exchangers, and slurry feed manifolds for the SRC-I Demonstration Plant. Because of lack of funds, the program was terminated before most of the work was completed. Two studies related to distribution of two-phase flow in the heat exchanger tubes were finished. A special system was designed to measure slurry concentration and flow rate in different tubes. Results showed that withdrawing slurry samples from the sides of the tubes gives a reasonably accurate measure of the concentration. Flow rate was measured indirectly with a photodiode/digital counter arrangement that measured velocity of a gas slug injected in the tube. A simple linear correlation was found to exist between the average slurry velocity and the gas-slug velocity. 1 reference, 25 figures.

  2. Radial flow permeability testing of an argillaceous limestone.

    PubMed

    Selvadurai, A P S; Jenner, L

    2013-01-01

    Argillaceous Lindsay limestone is the geologic storage formation that will be encountered at the site for the construction of a deep ground repository in Ontario, Canada, for the storage of low to intermediate level nuclear waste. The permeability of the Lindsay limestone is a key parameter that will influence the long-term movement of radionuclides from the repository to the geosphere. This paper describes the use of both steady-state and transient radial flow laboratory tests to determine the permeability of this argillaceous limestone. The interpretation of the tests is carried out using both analytical results and computational models of flow problems that exhibit radial symmetry. The results obtained from this research investigation are compared with the data available in the literature for similar argillaceous limestones mainly found in the Lindsay (Cobourg) formation. The experiments give permeabilities in the range of 1.0 × 10(-22) to 1.68 × 10(-19) m(2) for radial flows that are oriented along bedding planes under zero axial stress. The factors influencing transient pulse tests in particular and the interpretation of the results are discussed. PMID:22489872

  3. Macrodispersion by diverging radial flows in randomly heterogeneous porous media

    NASA Astrophysics Data System (ADS)

    Severino, Gerardo; Santini, Alessandro; Sommella, Angelo

    2011-04-01

    Radial flow takes place in a heterogeneous porous formation where the transmissivity T is modelled as a stationary random space function ( RSF). The steady flow is driven by a given rate, and the mean velocity is radial. A pulse-like of a tracer is injected in the porous formation, and the thin plume spreads due to the fluctuations of the velocity which results a RSF as well. Transport is characterized by the mean front, and by the second spatial moment of the plume. We are primarily interested in tracer macrodispersion modelling. With the neglect of pore-scale dispersion, macrodispersion coefficients are computed at the second order of approximation, without neglecting the head-gradient fluctuations. Although transport is non-ergodic at the source, it is shown that ergodicity is achieved at small distances from the source. This is due to the fact that close to the source local velocities are quite large, and therefore solute particles become uncorrelated very soon. Under ergodic conditions, we compare macrodispersion mechanism in radial flows with that occurring in mean uniform flows. At short distances the spreading effect is highly enhanced by the large variability of the flow field, whereas at large distances transport exhibits a lesser dispersion due to the reduction of velocities. This supports the explanation provided by Indelman and Dagan (1999) to justify why the macrodispersivity is found smaller than that pertaining to mean uniform flows. The model is tested against a tracer transport experiment (Fernàndez-Garcia et al., 2004) by comparing the theoretical and experimental breakthrough curves. The accordance with real data, that is achieved without any fitting to concentration values, strengthens the capability of the proposed model to grasp the main features of such an experiment, the approximations as well as experimental uncertainties notwithstanding.

  4. Gas/slurry flow in coal liquefaction processes (fluid dynamics in 3-phase flow columns)

    NASA Astrophysics Data System (ADS)

    Ying, D. H. S.; Sivasubramanian, R.; Givens, E. N.

    1981-02-01

    The need for additional data on behavior of three phase systems in large vessels was addressed. Parameters are investigated at conditions that relate directly to the projected demonstration plant operating conditions. Air/water/sand three phase flow system in both a 5 inch diameter and a 12 inch diameter column is used in this cold flow simulation program. The type of distributor used does not seem to affect the solids distribution profiles. The amount of solids retained in the column increases linearly with decreasing slurry velocity while changes in linear gas velocity does not affect the solids distribution profiles for the conditions studied. It is indicated that withdrawing solids from the bottom of the column results in a decreased amount of solids in the column and the solids concentration profile changes accordingly. It is shown that large particles were preferentially removed by virtue of their faster settling rate. The effects of settled particles and particle/particle interaction on solids accumulation were investigated. It it indicated that the presence of large particles does not influence the accumulation or distribution of fine particles. The column enclosure was completed and tested to identify the organic liquid/liquid which is to be used in the 12 inch diameter column.

  5. The stability of Taylor-Couette flow with radial heating

    NASA Astrophysics Data System (ADS)

    Ali, Mohamed El-Sayed

    The stability of circular Couette flow with radial heating across vertically oriented coaxial cylinders is investigated using linearized stability theory. The physical problem is governed by five parameters: the Taylor number Ta, the Groshof number G, the Prandtl number Pr, the cylinder aspect ration A, and the radius ratio eta. In the model infinite aspect ratio is assumed and critical stability boundaries are calculated for a conduction regime base flow. A rational analysis is made to derive the full governing perturbation equations and test flow stability subject to both axisymmetric and nonaxisymmetric disturbances. The flow may be driven to instability by competition between centrifugal, buoyancy, and shear force mechanisms. In spite of this complexity, the existence of solution symmetries of the perturbation equations with respect to the sense of radial heating and the sense of cylinder rotation are proven. The linear boundary-value problem defined by 16 first-order differential equations is solved using the software package SUPORT in combination with the nonlinear equation solver SNSQE. Critical stability boundaries at fixed Pr and eta were determined by searching for the minimum value of either Ta or G over all wavelengths K and mode numbers n.

  6. Onset of radial flow in p+p collisions

    DOE PAGESBeta

    Jiang, Kun; Zhu, Yinying; Liu, Weitao; Chen, Hongfang; Li, Cheng; Ruan, Lijuan; Tang, Zebo; Xu, Zhangbu

    2015-02-23

    It has been debated for decades whether hadrons emerging from p+p collisions exhibit collective expansion. The signal of the collective motion in p+p collisions is not as clear as in heavy-ion collisions because of the low multiplicity and large fluctuation in p+p collisions. Tsallis Blast-Wave (TBW) model is a thermodynamic approach, introduced to handle the overwhelming correlation and fluctuation in the hadronic processes. We have systematically studied the identified particle spectra in p+p collisions from RHIC to LHC using TBW and found no appreciable radial flow in p+p collisions below √s = 900 GeV. At LHC higher energy of 7more » TeV in p+p collisions, the radial flow velocity achieves an average of (β) = 0.320 ± 0.005. This flow velocity is comparable to that in peripheral (40-60%) Au+Au collisions at RHIC. In addition, breaking of the identified particle spectra mT scaling was also observed at LHC from a model independent test.« less

  7. Radial accretion flows on static spherically symmetric black holes

    NASA Astrophysics Data System (ADS)

    Chaverra, Eliana; Sarbach, Olivier

    2015-08-01

    We analyze the steady radial accretion of matter into a nonrotating black hole. Neglecting the self-gravity of the accreting matter, we consider a rather general class of static, spherically symmetric and asymptotically flat background spacetimes with a regular horizon. In addition to the Schwarzschild metric, this class contains certain deformation of it, which could arise in alternative gravity theories or from solutions of the classical Einstein equations in the presence of external matter fields. Modeling the ambient matter surrounding the black hole by a relativistic perfect fluid, we reformulate the accretion problem as a dynamical system, and under rather general assumptions on the fluid equation of state, we determine the local and global qualitative behavior of its phase flow. Based on our analysis and generalizing previous work by Michel, we prove that for any given positive particle density number at infinity, there exists a unique radial, steady-state accretion flow which is regular at the horizon. We determine the physical parameters of the flow, including its accretion and compression rates, and discuss their dependency on the background metric.

  8. Onset of radial flow in p +p collisions

    NASA Astrophysics Data System (ADS)

    Jiang, Kun; Zhu, Yinying; Liu, Weitao; Chen, Hongfang; Li, Cheng; Ruan, Lijuan; Tang, Zebo; Xu, Zhangbu

    2015-02-01

    It has been debated for decades whether hadrons emerging from p +p collisions exhibit collective expansion. The signal of the collective motion in p +p collisions is not as clear or as clean as in heavy-ion collisions because of the low multiplicity and large fluctuation in p +p collisions. The Tsallis blast-wave (TBW) model is a thermodynamic approach, introduced to handle the overwhelming correlation and fluctuation in the hadronic processes. We have systematically studied the identified particle spectra in p +p collisions from the BNL Relativistic Heavy Ion Collider (RHIC) to the CERN Large Hadron Collider (LHC) using TBW and have found no appreciable radial flow in p +p collisions below √{s }=900 GeV. At the LHC higher energy of 7 TeV in p +p collisions, the radial flow velocity achieves an average value of <β >=0.320 ±0.005 . This flow velocity is comparable to that in peripheral (40-60%) Au +Au collisions at the RHIC. Breaking of the identified particle spectra mT scaling was also observed at the LHC from a model-independent test.

  9. Exact Convex Relaxation of Optimal Power Flow in Radial Networks

    SciTech Connect

    Gan, LW; Li, N; Topcu, U; Low, SH

    2015-01-01

    The optimal power flow (OPF) problem determines a network operating point that minimizes a certain objective such as generation cost or power loss. It is nonconvex. We prove that a global optimum of OPF can be obtained by solving a second-order cone program, under a mild condition after shrinking the OPF feasible set slightly, for radial power networks. The condition can be checked a priori, and holds for the IEEE 13, 34, 37, 123-bus networks and two real-world networks.

  10. Rapid Analysis of Copper Ore in Pre-Smelter Head Flow Slurry by Portable X-ray Fluorescence.

    PubMed

    Burnett, Brandon J; Lawrence, Neil J; Abourahma, Jehad N; Walker, Edward B

    2016-05-01

    Copper laden ore is often concentrated using flotation. Before the head flow slurry can be smelted, it is important to know the concentration of copper and contaminants. The concentration of copper and other elements fluctuate significantly in the head flow, often requiring modification of the concentrations in the slurry prior to smelting. A rapid, real-time analytical method is needed to support on-site optimization of the smelter feedstock. A portable, handheld X-ray fluorescence spectrometer was utilized to determine the copper concentration in a head flow suspension at the slurry origin. The method requires only seconds and is reliable for copper concentrations of 2.0-25%, typically encountered in such slurries. PMID:27006021

  11. A visual study of radial inward choked flow of liquid nitrogen

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Simoneau, R. J.; Hsu, Y. Y.

    1973-01-01

    A visual study of the radial inward choked flow of liquid nitrogen was conducted. Data and high speed moving pictures were obtained. The study indicated the following: (1) steady radial inward choked flow seems equivalent to steady choked flow through axisymmetric nozzles, (2) transient choked flows through the radial gap are not uniform and the discharge pattern appears as nonuniform impinging jets, and (3) the critical mass flow rate data for the transient case appear different from those of the steady case.

  12. Linear and radial flow targets for characterizing downhole flow in perforations

    SciTech Connect

    Deo, M. ); Tariq, S.M. ); Halleck, P.M. )

    1989-08-01

    Two types of sandstone targets are commonly used to test flow efficiency of shaped-charge jet perforations: linear targets, in which flow enters only the unperforated end of the cylindrical sample, and radial targets, in which flow enters through the end and sides of the sample. To determine which of these targets best represents downhole conditions, the flow distribution along the length of a perforation has been studied by three-dimensional (3D) finite-element analyses. Linear and radial laboratory targets have been compared with downhole perforations under varying conditions. For ideal perforations, the low-shot-density (LSD) case is adequately represented by the radial target, while the high-shot-density (HSD) case falls between the two targets. With realistic crushed and damaged zones, the HSD closely matches the linear target, and the LSD case falls between the two targets.

  13. Connecting the Rheological Behavior of Clathrate Hydrate Slurries to Flow Performance

    NASA Astrophysics Data System (ADS)

    Geri, Michela; Venkatesan, Rama; McKinley, Gareth; MIT Team; Chevron ETC Team

    2014-11-01

    Clathrate hydrates represent a major flow assurance issue for deep water drilling operations. To develop a proper constitutive model, an extensive set of rheological measurements has been performed on a model hydrate forming emulsion. Upon hydrate formation a sharp increase in the fluid viscosity is observed (by a factor of 100 to 1000). Steady shear measurements show that the hydrate slurry has a shear thinning behavior as well as a yield stress on the order of 1-10 Pa which increases with aging of the fluid. Thixotropy becomes evident as a hysteretic behavior in the flow curve, even when no rheological aging has occurred. Creep tests also reveal that the fluid microstructure accumulates back stress. Oscillatory measurements show that in the linear viscoelastic region hydrate slurries develop viscoelastic gel-like behavior with the elastic modulus exceeding the viscous modulus. These characteristics guide the development of an elastoviscoplastic constitutive model that can capture the salient dynamic features in simple unidirectional flows (e.g. steady or transient Poiseuille) such as apparent wall slip, plug flow or excessive pressure drop in start-up flow.

  14. Improving Energy Efficiency Via Optimized Charge Motion and Slurry Flow in Plant Scale Sag Mills

    SciTech Connect

    Raj K. Rajamani; Jose Angel Delgadillo

    2006-07-21

    A research team from the University of Utah is working to make inroads into saving energy in these SAG mills. In 2003, Industries of the Future Program of the Department of Energy tasked the University of Utah team to build a partnership between the University and the mining industry for the specific purpose of reducing energy consumption in SAG mills. A partnership was formed with Cortez Gold Mines, Kennecott Utah Copper Corporation, Process Engineering Resources Inc. and Outokumpu Technology. In the current project, Cortez Gold Mines played a key role in facilitating the 26-ft SAG mill at Cortez as a test mill for this study. According to plant personnel, there were a number of unscheduled shut downs to repair broken liners and the mill throughput fluctuated depending on ore type. The University team had two softwares, Millsoft and FlowMod to tackle the problem. Millsoft is capable of simulating the motion of charge in the mill. FlowMod calculates the slurry flow through the grate and pulp lifters. Based on this data the two models were fine-tuned to fit the Cortez SAG will. In the summer of 2004 a new design of shell lifters were presented to Cortez and in September 2004 these lifters were installed in the SAG mill. By December 2004 Cortez Mines realized that the SAG mill is drawing approximately 236-kW less power than before while maintaining the same level of production. In the first month there was extreme cycling and operators had to learn more. Now the power consumption is 0.3-1.3 kWh/ton lower than before. The actual SAG mill power draw is 230-370 kW lower. Mill runs 1 rpm lesser in speed on the average. The recirculation to the cone crusher is reduced by 1-10%, which means more efficient grinding of critical size material is taking place in the mill. All of the savings have resulted in reduction of operating cost be about $0.023-$0.048/ ton. After completing the shell lifter design, the pulp lifter design was taken up. Through a series of mill surveys and

  15. Axial development and radial non-uniformity of flow in packed columns.

    PubMed

    Park, Jaekeun C; Raghavan, Karthik; Gibbs, Stephen J

    2002-02-01

    Flow inhomogeneity and axial development in low-pressure chromatographic columns have been studied by magnetic resonance imaging velocimetry. The columns studied included (a) an 11.7-mm I.D. column packed with either 50 microm diameter porous polyacrylamide, or 99 or 780 microm diameter impermeable polystyrene beads, and (b) a 5-mm I.D. column commercially packed with 10 microm polymeric beads. The packing methods included gravity settling, slurry packing, ultrasonication, and dry packing with vibration. The magnetic resonance method used averaged apparent fluid velocity over both column cross-sections and fluid displacements greater than one particle diameter and hence permits assessment of macroscopic flow non-uniformities. The results confirm that now non-uniformities induced by the conical distributor of the 11.7-mm I.D. column or the presence of voids at the column entrance relax on a length scale of the column radius. All of the 11.7-mm I.D. columns examined exhibit near wall channeling within a few particle diameters of the wall. The origins of this behavior are demonstrated by imaging of the radial dependence of the local porosity for a column packed with 780 microm beads. Columns packed with the 99-microm beads exhibit reduced flow in a region extending from ten to three-to-five particle diameters from the wall. This velocity reduction is consistent with a reduced porosity of 0.35 in this region as compared to approximately 0.43 in the bulk of the column. Ultrasonicated and dry-packed columns exhibit enhanced flow in a region located between approximately eight and 20 particle diameters from the wall. This enhancement maybe caused by packing density inhomogeneity and/or particle size segregation caused by vibration during the packing process. No significant non-uniformities on length scales of 20 microm or greater were observed in the commercially packed column packed with 10 microm particles. PMID:11860146

  16. Using the refractive index matched technique to study the flow properties of slurries

    SciTech Connect

    Wildman, D J; Ekmann, J M; Kadambi, J R; Chen, R C

    1991-01-01

    In this study, Laser Doppler Velocimetry (LDV) is used to measure liquid and solid axial velocity profiles for slurries with solids loadings as great as 25 volume percent. Axial velocity profiles were measured during flow through straight horizontal pipe and through concentric contractions. These results are presented and compared. These same solid-liquid mixtures have been rheologically characterized. Yield stresses and shear thinning behavior have been observed in mixtures with solids loadings of 15 volume percent or greater. The theoretical analyses of Hanks and Dadia and Hanks and Ricks were applied to the flow data though the constant-diameter pipe where appropriate. The effect of the rheological properties on the flow properties through horizontal, constant-diameter pipe and concentric contraction geometry are discussed.

  17. Boiling radial flow in fractures of varying wall porosity

    SciTech Connect

    Barnitt, Robb Allan

    2000-06-01

    The focus of this report is the coupling of conductive heat transfer and boiling convective heat transfer, with boiling flow in a rock fracture. A series of experiments observed differences in boiling regimes and behavior, and attempted to quantify a boiling convection coefficient. The experimental study involved boiling radial flow in a simulated fracture, bounded by a variety of materials. Nonporous and impermeable aluminum, highly porous and permeable Berea sandstone, and minimally porous and permeable graywacke from The Geysers geothermal field. On nonporous surfaces, the heat flux was not strongly coupled to injection rate into the fracture. However, for porous surfaces, heat flux, and associated values of excess temperature and a boiling convection coefficient exhibited variation with injection rate. Nucleation was shown to occur not upon the visible surface of porous materials, but a distance below the surface, within the matrix. The depth of boiling was a function of injection rate, thermal power supplied to the fracture, and the porosity and permeability of the rock. Although matrix boiling beyond fracture wall may apply only to a finite radius around the point of injection, higher values of heat flux and a boiling convection coefficient may be realized with boiling in a porous, rather than nonporous surface bounded fracture.

  18. An investigation of radial tracer flow in naturally fractured reservoirs

    SciTech Connect

    Jetzabeth, Ramirez-Sabag; Fernando, Samaniego V.; Jesus, Rivera R.; Fernando Rodriguez

    1991-01-01

    This study presents a general solution for the radial flow of tracers in naturally fractured reservoirs. Continuous and finite step injection of chemical and radioactive tracers are considered. The reservoir is treated as being composed of two regions: a mobile region where longitudinal dispersion and convection take place and a stagnant region where only diffusion and adsorption are allowed. Radioactive decay is considered in both regions. The model of this study is thoroughly compared to those previously presented in literature by Moench and Ogata, Tang et al., Chen et al., and Hsieh et al. The solution is numerically inverted by means of the Crump algorithm. A detailed validation of the model with respect to solutions previously presented and/or simplified physical conditions solutions (i.e., homogeneous case) or limit solutions (i.e., for short times) was carried out. The influence of various dimensionless parameters that enter into the solution was investigated. A discussion of results obtained through the Crump and Stehfest algorithm is presented, concluding that the Crump method provides more reliable tracer concentrations.

  19. Evaluation of the role of a cationic surfactant on the flow characteristics of fly ash slurry.

    PubMed

    Naik, H K; Mishra, M K; Rao Karanam, U M; Deb, D

    2009-09-30

    Transportation of fly ash is a major problem in its efficient disposal. The main problem associated with fly ash transportation is that the particles settle down sooner than desired. The primary objective of this research is that not only the fly ash particles should remain floated till it reaches the end but also settle down after that. In this investigation the role of a drag-reducing cationic surfactant and a counter-ion has been evaluated to achieve the objectives. The experimental results show encouraging trends of surfactant helping fly ash particles to remain water-borne. The material exhibited Newtonian behavior. This paper describes these in term of shear rates, shear stress, temperature, concentration and viscosity. Rheological tests were conducted using Advanced Computerized Rheometer. Zeta potential was measured to test the stability of the colloidal fly ash particles using Malvern Zeta Sizer instrument. Surface tension was also measured to know the drag reduction behavior of the fly ash slurry by using Surface Tensiometer. The test results and flow diagrams were generated using Rheoplus software and are presented in this paper. Surfactant concentration of 0%, 0.1%, 0.2%, 0.3%, 0.4% and 0.5% by weight was mixed with equal amount of counter-ion and the slurry was prepared by adding fly ash with ordinary tap water to achieve the desired solid concentration of 20% (by weight). PMID:19345482

  20. A visual study of radial inward choked flow of liquid nitrogen.

    NASA Technical Reports Server (NTRS)

    Hendricks, R. C.; Simoneau, R. J.; Hsu, Y. Y.

    1973-01-01

    Data and high speed movies were acquired on pressurized subcooled liquid nitrogen flowing radially inward through a 0.0076 cm gap. The stagnation pressure ranged from 0.7 to 4 MN/sq m. Steady radial inward choked flow appears equivalent to steady choked flow through axisymmetric nozzles. Transient choked flows through the radial gap are not uniform and the discharge pattern appears as nonuniform impinging jets. The critical mass flow rate data for the transient case appear different from those for the steady case. On the mass flow rate vs pressure map, the slope and separation of the isotherms appear to be less for transient than for steady radial choked flow.

  1. Computational investigations of axial and radial flow compressor aeromechanics

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, Kishore

    The focus of this research is aeromechanics issues in advanced compressors of the type used in modern day high thrust-to-weight ratio aircraft gas turbine engines. The driving factor for the studies undertaken is the High Cycle Fatigue (HCF) failure of gas turbine blades. HCF is a key technology issue in the development and endurance of gas turbine engines that arises primarily due to resonant response of turbomachine blading to unsteady aerodynamic excitation. Because it is a truly coupled nonlinear fluid-structure problem, predicting HCF requires a unified approach to modeling both the fluid and the structure. Considering the serious nature of HCF and the inadequacy of lower order design systems to accurately predict blade vibratory stress, the need to develop advanced predictive tools is pressing. The first aspect of this research therefore addresses the development of a turbomachinery coupled fluid-structure interaction tool to predict flow-induced blade vibration. To this end, the TAM-ALE3D solver is further developed as a derivative of the ALE3D code of Lawrence Livermore National Laboratory. In the second aspect of this research, TAM-ALE3D is validated by predicting viscous blade row unsteady aerodynamics and the modal properties of the stator vane in the baseline configuration of the Purdue Transonic Compressor. It is then used to predict the vane vibratory response excited by rotor wakes at resonance, with the resulting stresses in the range expected. For radial flow compressors, a very limited knowledge base exists on the unsteady aerodynamic and aeroelastic mechanisms that result in HCF. The bulk of this research is thus directed at the understanding of these fundamental unsteady phenomena using TAM-ALE3D as an investigative tool. The energy transfer from the downstream diffuser generated forcing function to the impeller blading is addressed by means of unsteady aerodynamic and aeroelastic analyses. From these computational investigations, the details of

  2. Buoyancy-driven flow reversal phenomena in radially rotating serpentine ducts

    SciTech Connect

    Hwang, J.J.; Wang, W.J.; Chen, C.K.

    2000-02-01

    Convective characteristics are analyzed numerically in a rotating multipass square duct connecting with 180-deg sharp returns. Isoflux is applied to each duct wall and periodic conditions are used between the entrance and exit of a typical two-pass module. Emphasis is placed on the phenomenon of buoyancy-driven reversed flow in the serpentine duct. Predictions reveal that the radial distance from the rotational axis to the location of flow separation in the radial-outward duct decreases with increasing the Richardson number. In addition, the local buoyancy that is required to yield the radial flow reversal increases with increasing the rotation number. This buoyancy-driven reversed flow in the radial-outward duct always results in local hot spots in the cooling channels. The critical buoyancy for the initiation of flow reversal is therefore concluded for the design purpose.

  3. One-dimensional analysis of plane and radial thin film flows including solid-body rotation

    NASA Technical Reports Server (NTRS)

    Thomas, S.; Hankey, W.; Faghri, A.; Swanson, T.

    1989-01-01

    The flow of a thin liquid film with a free surface along a horizontal plate which emanates from a pressurized vessel is examined by integrating the equations of motion across the thin liquid layer and discretizing the integrated equations using finite difference techniques. The effects of 0-g and solid-body rotation will be discussed. The two cases of interest are plane flow and radial flow. In plane flow, the liquid is considered to be flowing along a channel with no change in the width of the channel, whereas in radial flow the liquid spreads out radially over a disk, so that the area changes along the radius. It is desired to determine the height of the liquid film at any location along the plate of disk, so that the heat transfer from the plate or disk can be found. The possibility that the flow could encounter a hydraulic jump is accounted for.

  4. Radial Motions in Disk Stars: Ellipticity or Secular Flows?

    NASA Astrophysics Data System (ADS)

    López-Corredoira, M.; González-Fernández, C.

    2016-06-01

    Average stellar orbits of the Galactic disk may have some small intrinsic ellipticity which breaks the exact axisymmetry and there may also be some migration of stars inwards or outwards. Both phenomena can be detected through kinematic analyses. We use the red clump stars selected spectroscopically from the APO Galactic Evolution Experiment, with known distances and radial velocities, to measure the radial component of the Galactocentric velocities within 5 kpc < R < 16 kpc, | b| \\lt 5^\\circ , and within 20° from the Sun–Galactic center line. The average Galactocentric radial velocity is VR = (1.48 ± 0.35)[R(kpc) ‑ (8.8 ± 2.7)] km s‑1 outwards in the explored range, with a higher contribution from stars below the Galactic plane. Two possible explanations can be given for this result: (i) the mean orbit of the disk stars is intrinsically elliptical with a Galactocentric radial gradient of eccentricity around 0.01 kpc‑1 or (ii) there is a net secular expansion of the disk, in which stars within R ≈ 9–11 kpc are migrating to the region R ≳ 11 kpc at the rate of ∼2 M⊙ yr‑1, and stars with R ≲ 9 kpc are falling toward the center of the Galaxy. This migration ratio would be unattainable for a long time and should decelerate, otherwise the Galaxy would fade away in around 1 Gyr. At present, both hypotheses are speculative and one would need data on the Galactocentric radial velocities for other azimuths different to the center or anticenter in order to confirm one of the scenarios.

  5. On the Problem of Theoretical Pressure of a Radial-Flow Pump Unit

    NASA Astrophysics Data System (ADS)

    Pavlechko, V. N.; Protasov, S. K.

    2014-11-01

    An analysis has been made of the velocity of motion of a medium in the wheel of a radial-flow pump unit under the action of a centrifugal force and overcoming the medium's inertial force with its blades. Relations for the pressure produced by the radial-flow pump unit as a function of the angle of inclination of its blades have been derived. The well-known Euler equation describing the dynamic pressure of the radial-flow pump unit has been supplemented to determine its static pressure. An analysis of the obtained results has shown that the pressure of the radial-flow pump unit is maximum at an angle of inclination of its blades of 110o and negative at 140o or larger angles.

  6. Computer program for the analysis of the cross flow in a radial inflow turbine scroll

    NASA Technical Reports Server (NTRS)

    Hamed, A.; Abdallah, S.; Tabakoff, W.

    1977-01-01

    A computer program was used to solve the governing of the potential flow in the cross sectional planes of a radial inflow turbine scroll. A list of the main program, the subroutines, and typical output example are included.

  7. A methodology to define the flow rate and pressure requirements for transfer of double-shell tank waste slurries. Strategy plan

    SciTech Connect

    Bamberger, J.A.; Liljegren, L.M.

    1993-04-01

    This document presents an analysis of the pressure drop and flow rate double-shell tank slurries. Experiments to requirements for transport of characterize the transport of double-shell tank slurries through piping networks and to resuspend materials that settle during pump outages are proposed. Reported values of physical properties of double-shell tank slurries were analyzed to evaluate the flow regimes that are likely to occur during transport. The results of these evaluations indicate that the slurry will be pseudohomogeneous during transport and that the slurry rheology is sufficiently non-Newtonian to affect both the pressure drop achieved during transport and the critical Reynolds number. The transport data collected in the non-Newtonian experiment will be used to determine whether a non-Newtonian correlation developed by Hanks (1978) adequately describes the experimental results.

  8. Radial and elliptic flow at RHIC: Further predictions

    SciTech Connect

    Huovinen, Pasi; Kolb, Peter F.; Heinz, Ulrich; Ruuskanen, P.V.; Voloshin, Sergei A.

    2001-01-30

    Using a hydrodynamic model, we predict the transverse momentum dependence of the spectra and the elliptic flow for different hadrons in Au+Au collisions at sqrt(s)=130 AGeV. The dependence of the differential and p{_}t-integrated elliptic flow on the hadron mass, equation of state and freeze-out temperature is studied both numerically and analytically.

  9. Slurry bubble column hydrodynamics

    NASA Astrophysics Data System (ADS)

    Rados, Novica

    Slurry bubble column reactors are presently used for a wide range of reactions in both chemical and biochemical industry. The successful design and scale up of slurry bubble column reactors require a complete understanding of multiphase fluid dynamics, i.e. phase mixing, heat and mass transport characteristics. The primary objective of this thesis is to improve presently limited understanding of the gas-liquid-solid slurry bubble column hydrodynamics. The effect of superficial gas velocity (8 to 45 cm/s), pressure (0.1 to 1.0 MPa) and solids loading (20 and 35 wt.%) on the time-averaged solids velocity and turbulent parameter profiles has been studied using Computer Automated Radioactive Particle Tracking (CARPT). To accomplish this, CARPT technique has been significantly improved for the measurements in highly attenuating systems, such as high pressure, high solids loading stainless steel slurry bubble column. At a similar set of operational conditions time-averaged gas and solids holdup profiles have been evaluated using the developed Computed Tomography (CT)/Overall gas holdup procedure. This procedure is based on the combination of the CT scans and the overall gas holdup measurements. The procedure assumes constant solids loading in the radial direction and axially invariant cross-sectionally averaged gas holdup. The obtained experimental holdup, velocity and turbulent parameters data are correlated and compared with the existing low superficial gas velocities and atmospheric pressure CARPT/CT gas-liquid and gas-liquid-solid slurry data. The obtained solids axial velocity radial profiles are compared with the predictions of the one dimensional (1-D) liquid/slurry recirculation phenomenological model. The obtained solids loading axial profiles are compared with the predictions of the Sedimentation and Dispersion Model (SDM). The overall gas holdup values, gas holdup radial profiles, solids loading axial profiles, solids axial velocity radial profiles and solids

  10. Transient radial flow to a well in an unconfined aquifer

    SciTech Connect

    Narasimhan, T.N.; Zhu, Ming.

    1991-08-01

    The analytic solutions of Boulton (1954) and Neuman (1972) for transient flow to a well in an unconfined aquifer are based on the assumption that the role of the unsaturated zone can be adequately accounted for by restricting attention to the release of water from the zone through which the water table moves. Both researchers mathematically treat this released water as a time-dependent source term. The differences between the models of Boulton and Neuman are that the former neglects vertical components of flow in the aquifer, but allows for an exponential process for the release of water as a function of time, whereas the latter assumes instantaneous release from storage, but accounts for vertical components of flow. Given this set of assumptions, we examine the applicability of these two methods using a general purpose numerical model through a process of verification extension and comparison. The issues addressed include: the role of well-bore storage in masking intermediate-time behavior, combined effects of exponential release as well as vertical flow, logic for vertical averaging of drawdowns, and the sensitivity of system response to the magnitude of specific yield. The issue of how good the assumptions of Boulton and Neuman are in the context of the general theory of unsaturated flow is addressed in part 2 of this two-part series of reports.

  11. IMPROVING ENERGY EFFICIENCY VIA OPTIMIZED CHARGE MOTION AND SLURRY FLOW IN PLANT SCALE SAG MILLS

    SciTech Connect

    Raj K. Rajamani; Sanjeeva Latchireddi; Sravan K. Prathy; Trilokyanath Patra

    2005-12-01

    The U.S. mining industry operates approximately 80 semi-autogenesis grinding mills (SAG) throughout the United States. Depending on the mill size the SAG mills draws between 2 MW and 17 MW. The product from the SAG mill is further reduced in size using pebble crushers and ball mills. Hence, typical gold or copper ore requires between 2.0 and 7.5 kWh per ton of energy to reduce the particle size. Considering a typical mining operation processes 10,000 to 100,000 tons per day the energy expenditure in grinding is 50 percent of the cost of production of the metal. A research team from the University of Utah is working to make inroads into saving energy in these SAG mills. In 2003, Industries of the Future Program of the Department of Energy tasked the University of Utah team to build a partnership between the University and the mining industry for the specific purpose of reducing energy consumption in SAG mills. A partnership was formed with Cortez Gold Mines, Kennecott Utah Copper Corporation, Process Engineering Resources Inc. and others. In the current project, Cortez Gold Mines played a key role in facilitating the 26-ft SAG mill at Cortez as a test mill for this study. According to plant personnel, there were a number of unscheduled shut downs to repair broken liners and the mill throughput fluctuated depending on ore type. The University team had two softwares, Millsoft and FlowMod to tackle the problem. Millsoft is capable of simulating the motion of charge in the mill. FlowMod calculates the slurry flow through the grate and pulp lifters. Based on this data the two models were fine-tuned to fit the Cortez SAG will. In the summer of 2004 a new design of shell lifters were presented to Cortez and in September 2004 these lifters were installed in the SAG mill. By December 2004 Cortez Mines realized that the SAG mill is drawing approximately 236-kW less power than before while maintaining the same level of production. In the first month there was extreme cycling

  12. Three Phase Probabilistic Load Flow in Radial Distribution Networks

    SciTech Connect

    Melhorn, Alexander C; Dimitrovski, Aleksandar D; Tomsovic, Kevin L

    2012-01-01

    Probabilistic load flow is a helpful tool in accounting for inconsistent or unknown loads and generation. This is especially true with the push for renewable generation and demand response. This paper proposes an improved version of the probabilistic load flow solution for balanced distribution systems and takes the next step by applying it to unbalanced three phase systems. It is validated by comparing the solutions to that obtained by Monte Carlo simulation. The proposed method provides an accurate and practical way for finding the solution to the stochastic problems occurring in power distribution system analysis today.

  13. Phase Change Effects on Immiscible Flow Displacements in Radial Injection

    NASA Astrophysics Data System (ADS)

    Ahmadlouydarab, Majid; Azaiez, Jalel; Chen, Zhangxin

    2014-11-01

    We report a systematic simulation of immiscible fluid-fluid displacements in radial injection in the presence of phase change. Due to the presence of two fluid-fluid interfaces in the system, a special treatment has been adopted. To track the leading interface position, two highly accurate methods including Level Set and Immersed Interface Method were used, while for locating the trailing interface an energy equation was adopted assuming the existence of a constant thin condensate layer. Dimensional analysis led to three important dimensionless groups including capillary number (Ca), Jacob number (Ja) and viscosity ratios (M) of the three fluids. Simulation results indicate significant influences of these parameters on the development of the instability and the interfacial morphology of fingers. Increasing Ca or M tends to amplify the interfacial instability, fingertip splitting, and results in longer fingers. In contrast, increasing Ja has stabilizing effects due to an increase of the thickness of the condensate layer. On the other hand at lower viscosity ratios as well as lower Ca, because of compensation effects of the phase change, both leading and trailing interfaces are found to be less unstable. Moreover accumulated condensate and oil saturation depletion curves show increasing and decreasing trends, respectively, when the Ca increases. Although viscosity ratio and Ja have similar effects on the accumulated condensate, they do not show any effect on the oil depletion saturation.

  14. Investigations on the Aerodynamic Characteristics and Blade Excitations of the Radial Turbine with Pulsating Inlet Flow

    NASA Astrophysics Data System (ADS)

    Liu, Yixiong; Yang, Ce; Yang, Dengfeng; Zhang, Rui

    2016-04-01

    The aerodynamic performance, detailed unsteady flow and time-based excitations acting on blade surfaces of a radial flow turbine have been investigated with pulsation flow condition. The results show that the turbine instantaneous performance under pulsation flow condition deviates from the quasi-steady value significantly and forms obvious hysteretic loops around the quasi-steady conditions. The detailed analysis of unsteady flow shows that the characteristic of pulsation flow field in radial turbine is highly influenced by the pulsation inlet condition. The blade torque, power and loading fluctuate with the inlet pulsation wave in a pulse period. For the blade excitations, the maximum and the minimum blade excitations conform to the wave crest and wave trough of the inlet pulsation, respectively, in time-based scale. And toward blade chord direction, the maximum loading distributes along the blade leading edge until 20% chord position and decreases from the leading to trailing edge.

  15. Flow behavior in inlet guide vanes of radial turbines

    NASA Technical Reports Server (NTRS)

    Sokhey, J.; Tabakoff, W.; Hosny, W. M.

    1975-01-01

    Scroll flow is discussed. Streamline pattern and velocity distribution in the guide vanes are calculated. The blade surface temperature distribution is also determined. The effects of the blade shapes and the nozzle channel width on the velocity profiles at inlet to the guide vanes are investigated.

  16. Fluctuations of harmonic and radial flow in heavy ion collisions with principal components

    NASA Astrophysics Data System (ADS)

    Mazeliauskas, Aleksas; Teaney, Derek

    2016-02-01

    We analyze the spectrum of harmonic flow, vn(pT) for n =0 -5 , in event-by-event hydrodynamic simulations of Pb+Pb collisions at the CERN Large Hadron Collider (√{sN N}=2.76 TeV ) with principal component analysis (PCA). The PCA procedure finds two dominant contributions to the two-particle correlation function. The leading component is identified with the event plane vn(pT) , while the subleading component is responsible for factorization breaking in hydrodynamics. For v0, v1, and v3 the subleading flow is a response to the radial excitation of the corresponding eccentricity. By contrast, for v2 the subleading flow in peripheral collisions is dominated by the nonlinear mixing between the leading elliptic flow and radial flow fluctuations. In the v2 case, the sub-sub-leading mode more closely reflects the response to the radial excitation of ɛ2. A consequence of this picture is that the elliptic flow fluctuations and factorization breaking change rapidly with centrality, and in central collisions (where the leading v2 is small and nonlinear effects can be neglected) the sub-sub-leading mode becomes important. Radial flow fluctuations and nonlinear mixing also play a significant role in the factorization breaking of v4 and v5. We construct good geometric predictors for the orientation and magnitudes of the leading and subleading flows based on a linear response to the geometry, and a quadratic mixing between the leading principal components. Finally, we suggest a set of measurements involving three point correlations which can experimentally corroborate the nonlinear mixing of radial and elliptic flow and its important contribution to factorization breaking as a function of centrality.

  17. Preprocessor and postprocessor computer programs for a radial-flow finite-element model

    USGS Publications Warehouse

    Pucci, A.A., Jr.; Pope, D.A.

    1987-01-01

    Preprocessing and postprocessing computer programs that enhance the utility of the U.S. Geological Survey radial-flow model have been developed. The preprocessor program: (1) generates a triangular finite element mesh from minimal data input, (2) produces graphical displays and tabulations of data for the mesh , and (3) prepares an input data file to use with the radial-flow model. The postprocessor program is a version of the radial-flow model, which was modified to (1) produce graphical output for simulation and field results, (2) generate a statistic for comparing the simulation results with observed data, and (3) allow hydrologic properties to vary in the simulated region. Examples of the use of the processor programs for a hypothetical aquifer test are presented. Instructions for the data files, format instructions, and a listing of the preprocessor and postprocessor source codes are given in the appendixes. (Author 's abstract)

  18. Travel time statistics under radially converging flow in single fractures

    NASA Astrophysics Data System (ADS)

    Gotovac, Hrvoje; Srzic, Veljko; Cvetkovic, Vladimir; Kekez, Toni; Malenica, Luka

    2015-04-01

    A stochastic methodology based on Adaptive Fup Monte Carlo Method is used to investigate transport of a conservative solute by steady flow to a single pumping well in two-dimensional randomly heterogeneous single fractures. The spatially variable hydraulic transmissivity is modeled as a stationary random function for three different correlation structures (multi-Gaussian, connected and disconnected fields with correlated mean, high and low lnT values, respectively, according to the Zinn and Harvey, 2003) and heterogeneity levels (lnT variance is 1 and 8). Initially, solute particles are injected at outer circle located at 32 correlation lengths from well according to the in flux and resident injection mode. Therefore, breakthrough curve (BTC) statistics in single well due to different spatial structures, heterogeneity levels, injection modes and dispersion influence is considered. For small heterogeneity, all considered effects have small influences on BTC and related moments. As expected in single fractures, high lnT variance is more usual case which considerably changes flow patterns including channelling effect and fact that only few narrow channels carry out most pumping flow rate. Channelling implies significant differences between different injection modes. Resident mode uniformly injects particles implying that most particles pass through "slower" zones that especially increase late arrivals and contribute to the non-Fickian behaviour of transport. Contrary, "in flux" mode drastically reduces first arrivals and mean values, especially for connected correlation fields. The results from two injection modes lie on different sides of homogeneous mean travel time solution and give complementary information for complete representation of conservative transport. For advection transport, correlation structure and especially lnT variance seems to have major influence on BTC characteristics. On the other side, influence of longitudinal and lateral local scale

  19. 3-D model of a radial flow sub-watt methanol fuel processor

    SciTech Connect

    Holladay, J. D.; Wang, Y.

    2015-10-01

    A 3-D model is presented for a novel sub-watt packed bed reactor. The reactor uses an annular inlet flow combined with a radial flow packed bed reactor. The baseline reactor is compared to a reactor with multiple outlets and a reactor with 3 internal fins. Increasing the outlets from 1 to 4 did improve the flow distribution, but did not increase the performance in the simulation. However, inserting fins allowed a decrease in temperature with same inlet flow of approximately 35K. Or the inlet flow rate could be increased by a factor of 2.8x while maintaining >99% conversion.

  20. Origin and stability of radial density stratification in vortical flow

    NASA Astrophysics Data System (ADS)

    Dixit, Harish; Govindarajan, Rama

    2009-11-01

    A density interface near a vortex winds into a spiral. In the absence of gravity we have shown numerically and through stability analysis that this leads to spiral Kelvin-Helmholtz and centrifugal Rayleigh-Taylor (CRT) instabilities, often reducing the life-time of the vortex dramatically. In this talk we focus on CRT instability, which is driven by centrifugal forces, so flows where the vortex core is heavier than the surroundings are expected to be unstable. Indeed, Sipp et al. (JFM, 2005) and Joly et al. (JFM, 2005), prescribing Gaussian vorticity and density profiles, find no instability in light-cored vortices. Surprisingly however, for some range of parameters, with a Rankine vortex and a step circular density jump we find that making the core lighter can lead to instability. The sharpness of the profiles are thus relevant. The mechanism for this instability, studied by constructing planar analogues in the form of stratified shear flows, bearing similarities with Craik & Adams (JFM, 1979), will be discussed. So will the nonlinear stages of these instabilities from our direct numerical simulations.

  1. EXPERIMENTAL CHARACTERIZATION OF COHERENT, RADIALLY-SHEARED ZONAL FLOWS IN THE DIII-D TOKAMAK

    SciTech Connect

    MCKEE,GR; FONCK,RJ; JAKUBOWSKI,M; BURRELL,KH; HALLATSCHEK,K; MOYER,RA; NEVINS,W; PORTER,GD; RUDAKOV,DL; XU,X

    2002-11-01

    A271 EXPERIMENTAL CHARACTERIZATION OF COHERENT, RADIALLY-SHEARED ZONAL FLOWS IN THE DIII-D TOKAMAK. Application of time-delay-estimation techniques to two-dimensional measurements of density fluctuations, obtained with beam emission spectroscopy in DIII-D plasmas, has provided temporally and spatially resolved measurements of the turbulence flow-field. Features that are characteristic of self-generated zonal flows are observed in the radial region near 0.85 {<=} r/a {<=} 1.0. These features include a coherent oscillation (approximately 15 kHz) in the poloidal flow of density fluctuations that has a long poloidal wavelength, possibly m = 0, narrow radial extent (k{sub r}{rho}{sub I} < 0.2), and whose frequency varies monotonically with the local temperature. The approximate effective shearing rate, dv{sub {theta}}/dr, of the flow is of the same order of magnitude as the measured nonlinear decorrelation rate of the turbulence, and the density fluctuation amplitude is modulated at the frequency of the observed flow oscillation. Some phase coherence is observed between the higher wavenumber density fluctuations and low frequency poloidal flow fluctuations, suggesting a Reynolds stress contribution. These characteristics are consistent with predicted features of zonal flows, specifically identified as geodesic acoustic modes, observed in 3-D Braginskii simulations of core/edge turbulence.

  2. Slurry flow and structures formation in a magma mush: the Basement Sill, McMurdo Dry Valleys, Antarctica

    NASA Astrophysics Data System (ADS)

    Petford, N.; Jerram, D.; Davidson, J.

    2005-12-01

    The McMurdo Dry Valleys magmatic system, Antarctica, forming part of the Ferrar dolerite Large Igneous Province, comprises a vertical stack of four interconnected sills linked to surface flows of the Kirkpatrick flood basalts1. The lowermost intrusion, the Basement Sill, offers unprecedented exposure through a magmatic slurry flow (congested melt-particle mixture), comprised of abundant Opx pheoncrysts (MgO up to 20%). The overall geometry of the axially confined slurry is tongue-like, with the sill margins relatively aphiric2. The 3D nature of the exposure (100%) permits petrographical and structural observations to be made in unprecedented detail. Key properties of the Opx tongue that have bearing upon emplacement and solidification include microscale matrix properties (grain size, roughness, porosity and permeability, packing density and fluctuations), and the assumed fluid properties (viscosity and density) of the intergranular melt phase. These and other structures related to transport phenomena and deformation of the slurry during flow constitute the initial conditions for sophisticated physics-based modeling of the magma emplacement process. Initial results of a 2D numerical model employing a generalised form of the Navier- Stokes equations will be presented. It is noteworthy that features long recognized in classical layered intrusions formed here on a timescale (short) governed by the local cooling rate of a c. 300 m thick sill. A distinction between structures formed during transport, where the shearing regime dominates, and post- emplacement features due to mechanical compaction of the mush, is required. Information on conditions under which the touching Opx framework may collapse to expel interstitial fluid is also under investigation. 1. Marsh, B. (2004), Eos, 85, 497-502, 2004. 2. Charrier, A & Marsh, B. (2004), Eos Trans AGU 85, v24A-03.

  3. Modelling of turbulent flow in a radial reactor with fixed bed

    NASA Astrophysics Data System (ADS)

    Zhapbasbayev, U. K.; Ramazanova, G. I.; Kenzhaliev, O. B.

    2015-03-01

    The data of the computation of turbulent flow in the CF- π and CP- π configurations of the radial reactor with a fixed bed are presented. The Reynolds motion equations have been solved jointly with the k- ɛ turbulence model. To couple the parameters of flows at the interface free part-fixed bed the classical continuity equations were used. The computational data are obtained for the averaged and turbulent characteristics, and it is shown that the flow in the fixed bed causes the generation of the turbulence kinetic energy and its dissipation rate; the flow in the CF- π configuration is distributed more uniformly as compared to the CP- π configuration of the radial reactor. Computed data are compared with the experimental ones.

  4. Prediction of heat transfer to a thin liquid film in plane and radially spreading flows

    NASA Technical Reports Server (NTRS)

    Rahman, M. M.; Faghri, A.; Hankey, W. L.; Swanson, T. D.

    1990-01-01

    The energy equation is incorporated in the solution algorithm of Rahman et al. (1990) to compute the heat transfer to a thin film in the presence or absence of gravity. For a plane flow under zero gravity, it is found that, for both isothermal and uniformly heated walls, the heat transfer coefficient gradually decreases downstream, with Nu-asterisk (the Nusselt number in terms of film height) remaining approximately constant except for regions very close to the entrance. In the case of radial flow under zero gravity, Nu-asterisk is found to decrease monotonically when the plane is uniformly heated. Two different flow regimes are identified in the presence of gravity for both plane and radial flows. The results of the study may be applicable to the design of space-based cooling systems.

  5. Mathematical modeling of three-phase slurry bubble column reactors

    SciTech Connect

    Gamwo, I.K.; Soong, Y.; Schehl, R.R.; Zarochak, M.F.

    1994-12-31

    The behavior of gas-solid-liquid flow in a slurry bubble column reactor was simulated using a well-posed hydrodynamic model. The three phases under study are nitrogen, 5-{mu}m iron oxide, and SASOL wax. The phases volume fractions at various axial and radial positions in the column were computed. Preliminary results of axial solid volume fractions are consistent with experimental observations and demonstrate the potential of this method for design of such reactors. The overall objective of this study is to develop experimentally verified hydrodynamic and Fisher-Tropsch reaction models for slurry bubble column reactors.

  6. Radial Flow Fludized Filter Finds Niche as a Pretreatment System for Surface Water in Small Communities

    EPA Science Inventory

    An emerging technology called radial flow fluidized filter (R3f) has been developed as a low cost simplistic filtration technology for small communities of less than 10,000 people. Fouling is a major impediment to the sustainability of membrane technology particularly for small ...

  7. Solids removal from a coldwater recirculating system - comparison of swirl separator and radial-flow settlers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solids removal across two settling devices, i.e., a swirl separator and a radial-flow settler, and across a microscreen drum filter was evaluated in a fully recirculating system containing a single 150 m3 'Cornell-type' dual-drain tank during the production of food-size Arctic char and rainbow trout...

  8. Response of a radial-bladed centrifugal pump to sinusoidal disturbances for noncavitating flow

    NASA Technical Reports Server (NTRS)

    Anderson, D. A.; Blade, R. J.; Stevans, W.

    1971-01-01

    A radial-bladed centrifugal pump was run in water with sinusoidal fluctuations of pressure and flow rate imposed at the pump inlet. Since the flow was noncavitating, zero gain was assumed in computing pump impedance. The inertive reactance became greater than the resistance at relatively low frequencies. An electric circuit model was developed in order to explain the trends of inertance and resistance with frequency.

  9. Designing and updating the flow part of axial and radial-axial turbines through mathematical modeling

    NASA Astrophysics Data System (ADS)

    Rusanov, Andrey; Rusanov, Roman; Lampart, Piotr

    2015-10-01

    The paper describes an algorithm for the design of axial and radial-axial type turbines. The algorithm is based on using mathematical models of various levels of complexity - from 1D to 3D. Flow path geometry is described by means of analytical methods of profiling using a limited number of parameters. 3D turbulent flow model is realised in the program complex IPMFlow, developed based on the earlier codes FlowER and FlowER-U. Examples of developed or modernized turbines for differentpurpose power machines are presented. They are: an expansion turbine, ORC turbine and cogeneration mediumpressure turbine.

  10. Laminar flow between a stationary and a rotating disk with radial throughflow

    SciTech Connect

    Nesreddine, H.; Nguyen, C.T.; Vo-Ngoc, D.

    1995-05-01

    The problem of axisymmetric laminar flow of a viscous incompressible fluid that occurs between a stationary and a rotating disk subjected to a uniform radial throughflow has been numerically investigated for a large range of flow parameters. Results show that the basic flow structure is rather complex and depends strongly on both the rotational and the flow structure is rather complex and depends strongly on both the rotational and the throughflow Reynolds numbers. In general, the basic unicellular structure has been observed. With the increase of the throughflow Reynolds number, a multicellular flow structure may be found. The phenomenon of multiple solutions has been clearly observed for cases with sufficiently high rational Re and/or high throughflow Re. Among these solutions, stable as well as unstable solutions have been determined by applying Rayleigh`s stability criterion. The influence of the starting conditions on the stability of the flow has also been investigated for various ranges of flow parameters.

  11. A model of unsteady spatially inhomogeneous flow in a radial-axial blade machine

    NASA Astrophysics Data System (ADS)

    Ambrozhevich, A. V.; Munshtukov, D. A.

    A two-dimensional model of the gasdynamic process in a radial-axial blade machine is proposed which allows for the instantaneous local state of the field of flow parameters, changes in the set angles along the median profile line, profile losses, and centrifugal and Coriolis forces. The model also allows for the injection of cooling air and completion of fuel combustion in the flow. The model is equally applicable to turbines and compressors. The use of the method of singularities provides for a unified and relatively simple description of various factors affecting the flow and, therefore, for computational efficiency.

  12. Simulating MODFLOW-based reactive transport under radially symmetric flow conditions.

    PubMed

    Wallis, Ilka; Prommer, Henning; Post, Vincent; Vandenbohede, Alexander; Simmons, Craig T

    2013-01-01

    Radially symmetric flow and solute transport around point sources and sinks is an important specialized topic of groundwater hydraulics. Analysis of radial flow fields is routinely used to determine heads and flows in the vicinity of point sources or sinks. Increasingly, studies also consider solute transport, biogeochemical processes, and thermal changes that occur in the vicinity of point sources/sinks. Commonly, the analysis of hydraulic processes involves numerical or (semi-) analytical modeling methods. For the description of solute transport, analytical solutions are only available for the most basic transport phenomena. Solving advanced transport problems numerically is often associated with a significant computational burden. However, where axis-symmetry applies, computational cost can be decreased substantially in comparison with full three-dimensional (3D) solutions. In this study, we explore several techniques of simulating conservative and reactive transport within radial flow fields using MODFLOW as the flow simulator, based on its widespread use and ability to be coupled with multiple solute and reactive transport codes of different complexity. The selected transport simulators are MT3DMS and PHT3D. Computational efficiency and accuracy of the approaches are evaluated through comparisons with full 2D/3D model simulations, analytical solutions, and benchmark problems. We demonstrate that radial transport models are capable of accurately reproducing a wide variety of conservative and reactive transport problems provided that an adequate spatial discretization and advection scheme is selected. For the investigated test problems, the computational load was substantially reduced, with the improvement varying, depending on the complexity of the considered reaction network. PMID:22900478

  13. Full-scale cold-flow modelling of the SRC-I slurry fired heater at Creare, Inc

    SciTech Connect

    Mehta, D.C.

    1983-09-01

    The slurry fired heater is a crucial piece of equipment in the SRC-I Demonstration Plant. The design of the fired heater has not been tested in any other plant under a similar combination of operating severity and multiphase flow. The cold-flow modelling experiments were conducted to confirm the fired heater design and to develop acceptable boundaries of flow rates for proper operation of the fired heater. The primary objectives were to identify the flow regimes, estimate pressure drops and measure heat transfer coefficients at a variety of fired heater operating conditions. The results definitively confirm the presence of a slug flow regime in the fired heater at the full range of operating conditions. Slug flow is desirable to avoid coking and excessive temperature gradients in the heater pipes and because of its relatively low pressure drop. The gas holdup predictions by the Hughmark correlation were in good agreement with the experimental results. A simplified correlation was developed to calculate gas holdup in the SRC-I fired heater pipes. The pressure drop results also confirmed that the experimental values were less than the design values. The Hughmark correlation was able to predict the pressure drop for the viscous fluids within +-20% of the measured value. The heat transfer coefficients calculated from the experiments were almost twice as high as those used in the design of the fired heater. The tests were successful based on the data developed, and the results confirm the fired heater design and indicate flexibilities in its operation.

  14. Stability results for multi-layer radial Hele-Shaw and porous media flows

    NASA Astrophysics Data System (ADS)

    Gin, Craig; Daripa, Prabir

    2015-01-01

    Motivated by stability problems arising in the context of chemical enhanced oil recovery, we perform linear stability analysis of Hele-Shaw and porous media flows in radial geometry involving an arbitrary number of immiscible fluids. Key stability results obtained and their relevance to the stabilization of fingering instability are discussed. Some of the key results, among many others, are (i) absolute upper bounds on the growth rate in terms of the problem data; (ii) validation of these upper bound results against exact computation for the case of three-layer flows; (iii) stability enhancing injection policies; (iv) asymptotic limits that reduce these radial flow results to similar results for rectilinear flows; and (v) the stabilizing effect of curvature of the interfaces. Multi-layer radial flows have been found to have the following additional distinguishing features in comparison to rectilinear flows: (i) very long waves, some of which can be physically meaningful, are stable; and (ii) eigenvalues can be complex for some waves depending on the problem data, implying that the dispersion curves for one or more waves can contact each other. Similar to the rectilinear case, these results can be useful in providing insight into the interfacial instability transfer mechanism as the problem data are varied. Moreover, these can be useful in devising smart injection policies as well as controlling the complexity of the long-term dynamics when drops of various immiscible fluids intersperse among each other. As an application of the upper bound results, we provide stabilization criteria and design an almost stable multi-layer system by adding many layers of fluid with small positive jumps in viscosity in the direction of the basic flow.

  15. Lapping slurry

    DOEpatents

    Simandl, R.F.; Upchurch, V.S.; Leitten, M.E.

    1999-01-05

    Improved lapping slurries provide for easier and more thorough cleaning of alumina work pieces, as well as inhibit corrosion of the lapping table and provide for easier cleaning of the lapping equipment. The unthickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, and triethanolamine. The thickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, triethanolamine, a water soluble silicate, and acid. 1 fig.

  16. Lapping slurry

    DOEpatents

    Simandl, Ronald F.; Upchurch, Victor S.; Leitten, Michael E.

    1999-01-01

    Improved lapping slurries provide for easier and more thorough cleaning of alumina workpieces, as well as inhibit corrosion of the lapping table and provide for easier cleaning of the lapping equipment. The unthickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, and triethanolamine. The thickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, triethanolamine, a water soluble silicate, and acid.

  17. Slurry pipelines

    SciTech Connect

    Wasp, E.J.

    1983-11-01

    Slurry pipelines are now transporting metal ores and coal/water suspensions. Their greatest potential is for transporting coal from Western states to power stations in other parts of the country. The physics of slurry transport encompases the principles of fluid dynamics and hydrostatics that were studied by Archimedes, but commercial slurry systems date only since World War II. An overview of their development covers policy debates and technological problems associated with existing and proposed pipeline projects. The author examines the tradeoffs of low sulfur content versus longer distances for transport, and describes the process of preparing coal slurries. 7 figures.

  18. Radial artery cannulation--the influence of method on blood flow after decannulation.

    PubMed

    Cronin, K D; Davies, M J; Domaingue, C M; Worner, M J; Koumoundouros, E

    1986-11-01

    A prospective randomised study of two hundred patients undergoing open-heart surgery was carried out to determine if the method of radial artery cannulation (direct threading or transfixion) had any influence on the incidence of abnormal flow after decannulation. A standard 20-gauge non-tapered teflon-coated cannula was used and the groups were well matched for age, sex, wrist circumference, duration of cannulation and haematoma formation, all of which have been postulated to influence thrombosis rate. We were unable to demonstrate a statistically significant difference between the two methods of cannulation. The overall abnormal flow rate at five days assessed by Doppler ultrasound was low at 5%. PMID:2952029

  19. Laser velocimeter measurements in shrouded and unshrouded radial flow pump impellers

    NASA Technical Reports Server (NTRS)

    Hamkins, C. P.; Flack, R. D.

    1986-01-01

    Shrouded and unshrouded versions of a four-vaned radial flow impeller with a design flow coefficient of 0.063 were tested in a volute pump using a two-component frequency-shifted laser velocimeter. Velocity profiles were measured at six flow rates and at four radial and six circumferential positions in the volute. The variations of the velocity from blade to blade and in the axial direction were measured and are presented. A passage vortex caused by tip leakage and relative casing wall velocity was found in the unshrouded impeller. The tip leakage did not accumulate in the suction wake region; the suction wake region was only 30 to 50 percent as large in the unshrouded impeller as compared to the shrouded impeller. The slip was 30 percent higher in the unshrouded impeller and the variation of slip with flow rate is presented. At no measured position in the impellers did the slip factor reach unity; the closest approach was 0.90. Reverse loadings of the vanes at outer radii were found for flow rates below the impeller/volute matching point for both impellers.

  20. DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

    SciTech Connect

    Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

    2010-09-01

    The Hybrid Energy Systems Testing (HYTEST) Laboratory is being established at the Idaho National Laboratory to develop and test hybrid energy systems with the principal objective to safeguard U.S. Energy Security by reducing dependence on foreign petroleum. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions will be performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. SBCRs are cylindrical vessels in which gaseous reactants (for example, synthesis gas or syngas) is sparged into a slurry of liquid reaction products and finely dispersed catalyst particles. The catalyst particles are suspended in the slurry by the rising gas bubbles and serve to promote the chemical reaction that converts syngas to a spectrum of longer chain hydrocarbon products, which can be upgraded to gasoline, diesel or jet fuel. These SBCRs operate in the churn-turbulent flow regime which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer, that effect reactor performance. The purpose of this work is to develop a computational multiphase fluid dynamic (CMFD) model to aid in understanding the physico-chemical processes occurring in the SBCR. Our team is developing a robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) that includes twelve species: (1) CO reactant, (2) H2 reactant, (3) hydrocarbon product, and (4) H2O product in small bubbles, large bubbles, and the bulk fluid. Properties of the hydrocarbon product were specified by vapor liquid equilibrium calculations. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is determined based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield [1]. The

  1. Comparison of the flows and radial electric field in the HSX stellarator to neoclassical calculations

    NASA Astrophysics Data System (ADS)

    Briesemeister, A.; Zhai, K.; Anderson, D. T.; Anderson, F. S. B.; Talmadge, J. N.

    2013-01-01

    Intrinsic flow velocities of up to ˜20 km s-1 have been measured using charge exchange recombination spectroscopy (CHERS) in the quasi-helically symmetric HSX stellarator and are compared with the neoclassical values calculated using an updated version (Lore 2010 Measurement and Transport Modeling with Momentum Conservation of an Electron Internal Transport Barrier in HSX (Madison, WI: University of Wisconsin); Lore et al 2010 Phys. Plasmas 17 056101) of the PENTA code (Spong 2005 Phys. Plasmas. 12 056114). PENTA uses the monoenergetic transport coefficients calculated by the drift kinetic equation solver code (Hirshman et al 1986 Phys. Fluids 29 2951; van Rij and Hirshman 1989 Phys. Fluids B 1 563), but corrects for momentum conservation. In the outer half of the plasma good agreement is seen between the measured parallel flow profile and the calculated neoclassical values when momentum correction is included. The flow velocity in HSX is underpredicted by an order of magnitude when this momentum correction is not applied. The parallel flow is calculated to be approximately equal for the majority hydrogen ions and the C6+ ions used for the CHERS measurements. The pressure gradient of the protons is the primary drive of the calculated parallel flow for a significant portion of the outer half of the plasma. The values of the radial electric field calculated with and without momentum correction were similar, but both were smaller than the measured values in the outer half of the plasma. Differences between the measured and predicted radial electric field are possibly a result of uncertainty in the composition of the ion population and sensitivity of the ion flux calculation to resonances in the radial electric field.

  2. An analysis of the viscous flow through a compact radial turbine by the average passage approach

    NASA Technical Reports Server (NTRS)

    Heidmann, James D.; Beach, Timothy A.

    1990-01-01

    A steady, three-dimensional viscous average passage computer code is used to analyze the flow through a compact radial turbine rotor. The code models the flow as spatially periodic from blade passage to blade passage. Results from the code using varying computational models are compared with each other and with experimental data. These results include blade surface velocities and pressures, exit vorticity and entropy contour plots, shroud pressures, and spanwise exit total temperature, total pressure, and swirl distributions. The three computational models used are inviscid, viscous with no blade clearance, and viscous with blade clearance. It is found that modeling viscous effects improves correlation with experimental data, while modeling hub and tip clearances further improves some comparisons. Experimental results such as a local maximum of exit swirl, reduced exit total pressures at the walls, and exit total temperature magnitudes are explained by interpretation of the flow physics and computed secondary flows. Trends in the computed blade loading diagrams are similarly explained.

  3. Design and flow field calculations for transonic and supersonic radial inflow turbine guide vanes

    SciTech Connect

    Reichert, A.W.; Simon, H.

    1997-01-01

    The design of radial inflow turbine guide vanes depends very much on the discharge conditions desired, especially if the choking mass flow is reached. Because of the choking mass flow condition and supersonic discharge Mach numbers, an inverse design procedure based on the method of characteristics is presented. Various designs corresponding to different discharge Mach numbers are shown. Viscous and inviscid flow field calculations for varying discharge conditions show the properties of the guide vanes at design and off-design conditions. In a previous paper (Reichert and Simon, 1994), an optimized design for transonic discharge conditions has been published. In the present paper, additional results concerning the optimum design are presented. For this optimum design an advantageous adjusting mechanism for a variable geometry guide vane has been developed. The effect of guide vane adjustment on the discharge conditions has been investigated using viscous flow field calculations.

  4. Technique to Measure the Coronal Electron Temperature and Radial Flow Speed

    NASA Astrophysics Data System (ADS)

    Reginald, N. L.; Davila, J. M.; St Cyr, O. C.

    2011-12-01

    During the March 2006 total solar eclipse we conducted an imaging experiment using the Imaging Spectrograph of Coronal Electrons (ISCORE) to determine the coronal electron temperature and its radial flow speed in the low solar corona. This technique required taking images of the solar eclipse through four broadband filters centered at 385.0, 398.7, 410.0 and 423.3 nm. The K-coronal temperature is determined from intensity ratios from the 385.0 and 410.0 nm filters, and the K-coronal radial flow speed is determined from intensity ratios from the 398.7 and 423.3 nm filters. The theoretical model for this technique assumes a symmetric corona devoid of any features like streamers that might alter the coronal symmetry. The model also requires an isothermal temperature and a uniform outflow speed all along the line of sight. We will call this the Constant Parameter Thomson Scattering Model (CPTSM). The latter assumption may sound unreasonable but in the symmetric corona with rapid fall of the electron density with height in the solar corona, the major contributions to the K-coronal intensity along a given line of sight comes from the plasma properties in the vicinity of the plane of the sky. But the pressing question is how is the derived plasma properties by ISCORE compare with the nature of the true corona. For this we turn to the CORHEL model by Predictive Science Inc. which used magnetogram data to create a realistic model of the solar corona that are made available through the Community Coordinated Modeling Center (CCMC) at GSFC. That team has consistently produced the expected coronal image days prior to many total eclipses where the major coronal features from their model matched actual coronal image on the day of the eclipse. Using the CORHEL model data we have calculated the K-coronal intensities at 385.0, 398.7, 410.0 and 423.3 nm using the electron density, plasma temperature (assumed to be electron temperature) and the flow speeds of the plasma along the line

  5. Cyclic and radial variation of ultrasonic backscatter from flowing porcine blood

    NASA Astrophysics Data System (ADS)

    Paeng, Dong-Guk

    The ultrasonic backscattering from flowing blood was investigated using several hemodynamic parameters and a physiological parameter. Acceleration was hypothesized to enhance the aggregation of red blood cells (RBCs), and this is the first time that acceleration is suggested and experimentally verified as having an effect on aggregation of RBC. Two interesting phenomena, the 'Black Hole (BH)' phenomenon and the 'Bright Collapsing Ring (BCR)' phenomenon, were observed under pulsatile flow in B-mode cross sectional images. The BH phenomenon describes a dark hypoechoic hole at the center of the tube surrounded by a bright hyperechoic zone in B-mode cross sectional images, and the BCR phenomenon describes the appearance of a bright hyperechoic ring at the periphery of the tube at early systole and its convergence from the periphery to the center of the tube, finally collapsing as flow develops. Doppler power variation was observed only from porcine whole blood, which led to a conclusion that the ultrasonic backscattering was mainly dependent on the RBC aggregation under steady and pulsatile flow. The pattern of the cyclic variation of the Doppler power to have a maximum power at peak systole was mainly due to the enhanced rouleaux formation by acceleration. The BCR phenomenon was observed from the cyclic variation pattern of the Doppler power at different radial positions; the Doppler power peak was observed at early systole at the periphery of the tube and lagged the flow as close from the periphery to the center of the tube. The BCR phenomenon from porcine whole blood in a mock flow loop was further examined in real time in B-mode images under pulsatile flow. At low hematocrit of 12%, no BCR phenomenon was discernable although it was observed at higher hematocrits. The pattern of the nonlinear relationship between echogenicity and hematocrit varied with radial positions. The BH phenomenon was also observed under certain hemodynamic conditions and varied over a

  6. On the nature of radial transport across sheared zonal flows in electrostatic ion-temperature-gradient gyrokinetic tokamak turbulence

    SciTech Connect

    Sanchez, Raul; Newman, David E; Leboeuf, Jean-Noel; Carreras, Benjamin A; Decyk, Viktor

    2009-01-01

    It is argued that the usual understanding of the suppression of radial turbulent transport across a sheared zonal flow based on a reduction in effective transport coefficients is, by itself, incomplete. By means of toroidal gyrokinetic simulations of electrostatic, ion-temperature-gradient turbulence, it is found instead that the character of the radial transport is altered fundamentally by the presence of a sheared zonal flow, changing from diffusive to anticorrelated and subdiffusive. Furthermore, if the flows are self-consistently driven by the turbulence via the Reynolds stresses (in contrast to being induced externally), radial transport becomes non-Gaussian as well. These results warrant a reevaluation of the traditional description of radial transport across sheared flows in tokamaks via effective transport coefficients, suggesting that such description is oversimplified and poorly captures the underlying dynamics, which may in turn compromise its predictive capabilities.

  7. On the nature of radial transport across sheared zonal flows in electrostatic ion-temperature-gradient gyrokinetic tokamak plasma turbulence

    SciTech Connect

    Sanchez, R.; Newman, D. E.; Leboeuf, J.-N.; Carreras, B. A.; Decyk, V. K.

    2009-05-15

    It is argued that the usual understanding of the suppression of radial turbulent transport across a sheared zonal flow based on a reduction in effective transport coefficients is, by itself, incomplete. By means of toroidal gyrokinetic simulations of electrostatic, ion-temperature-gradient turbulence, it is found instead that the character of the radial transport is altered fundamentally by the presence of a sheared zonal flow, changing from diffusive to anticorrelated and subdiffusive. Furthermore, if the flows are self-consistently driven by the turbulence via the Reynolds stresses (in contrast to being induced externally), radial transport becomes non-Gaussian as well. These results warrant a reevaluation of the traditional description of radial transport across sheared flows in tokamaks via effective transport coefficients, suggesting that such description is oversimplified and poorly captures the underlying dynamics, which may in turn compromise its predictive capabilities.

  8. Direct numerical simulation of Taylor-Couette flow subjected to a radial temperature gradient

    NASA Astrophysics Data System (ADS)

    Teng, Hao; Liu, Nansheng; Lu, Xiyun; Khomami, Bamin

    2015-12-01

    Direct numerical simulations have been performed to study the Taylor-Couette (TC) flow between two rotating, coaxial cylinders in the presence of a radial temperature gradient. Specifically, the influence of the buoyant force and the outer cylinder rotation on the turbulent TC flow system with the radius ratio η = 0.912 was examined. For the co-rotating TC flows with Rei (inner cylinder) =1000 and Reo (outer cylinder) =100, a transition pathway to highly turbulent flows is realized by increasing σ, a parameter signifying the ratio of buoyant to inertial force. This nonlinear flow transition involves four intriguing states that emerge in sequence as chaotic wavy vortex flow for σ = 0, wavy interpenetrating spiral flows for σ = 0.02 and 0.05, intermittent turbulent spirals for σ = 0.1 and 0.2, and turbulent spirals for σ = 0.4. Overall, the fluid motion changes from a centrifugally driven flow regime characterized by large-scale wavy Taylor vortices (TVs) to a buoyancy-dominated flow regime characterized by small-scale turbulent vortices. Commensurate changes in turbulence statistics and heat transfer are seen as a result of the weakening of large-scale TV circulations and enhancement of turbulent motions. Additionally, the influence of variation of the outer cylinder rotation, -500 < Reo < 500 in presence of buoyancy (σ = 0.1) with Rei = 1000, has been considered. Specifically, it is demonstrated that this variation strongly influences the azimuthal and axial mean flows with a weaker influence on the fluctuating fluid motions. Of special interest, here are the turbulent dynamics near the outer wall where a marked decrease of turbulence intensity and a sign inversion of the Reynolds stress Rrz are observed for the strongly counter-rotating regimes (Reo = - 300 and -500). To this end, it has been shown that the underlying flow physics for this drastic modification are associated with the modification of the correlation between the radial and axial fluctuating

  9. Direct numerical simulation of Taylor-Couette flow subjected to a radial temperature gradient

    SciTech Connect

    Teng, Hao; Liu, Nansheng Lu, Xiyun; Khomami, Bamin

    2015-12-15

    Direct numerical simulations have been performed to study the Taylor-Couette (TC) flow between two rotating, coaxial cylinders in the presence of a radial temperature gradient. Specifically, the influence of the buoyant force and the outer cylinder rotation on the turbulent TC flow system with the radius ratio η = 0.912 was examined. For the co-rotating TC flows with Re{sub i} (inner cylinder) =1000 and Re{sub o} (outer cylinder) =100, a transition pathway to highly turbulent flows is realized by increasing σ, a parameter signifying the ratio of buoyant to inertial force. This nonlinear flow transition involves four intriguing states that emerge in sequence as chaotic wavy vortex flow for σ = 0, wavy interpenetrating spiral flows for σ = 0.02 and 0.05, intermittent turbulent spirals for σ = 0.1 and 0.2, and turbulent spirals for σ = 0.4. Overall, the fluid motion changes from a centrifugally driven flow regime characterized by large-scale wavy Taylor vortices (TVs) to a buoyancy-dominated flow regime characterized by small-scale turbulent vortices. Commensurate changes in turbulence statistics and heat transfer are seen as a result of the weakening of large-scale TV circulations and enhancement of turbulent motions. Additionally, the influence of variation of the outer cylinder rotation, −500 < Re{sub o} < 500 in presence of buoyancy (σ = 0.1) with Re{sub i} = 1000, has been considered. Specifically, it is demonstrated that this variation strongly influences the azimuthal and axial mean flows with a weaker influence on the fluctuating fluid motions. Of special interest, here are the turbulent dynamics near the outer wall where a marked decrease of turbulence intensity and a sign inversion of the Reynolds stress R{sub rz} are observed for the strongly counter-rotating regimes (Re{sub o} = − 300 and −500). To this end, it has been shown that the underlying flow physics for this drastic modification are associated with the modification of the correlation

  10. Application of radial-equilibrium condition to axial-flow compressor and turbine design

    NASA Technical Reports Server (NTRS)

    Wu, Chung-Hua; Wolfenstein, Lincoln

    1950-01-01

    Basic general equations governing the three-dimensional compressible flow of gas through a compressor or turbine are given in terms of total enthalpy, entropy, and velocity components of the gas. Two methods of solution are obtained for the simplified, steady axially symmetric flow; one involves the use of a number of successive planes normal to the axis of the machine and short distances apart, and the other involves only three stations for a stage in which an appropriate radial-flow path is used. Methods of calculation for the limiting cases of zero and infinite blade aspect ratios and an approximate method of calculation for finite blade aspect ratio are also given. In these methods, the blade loading and the shape of the annular passage wall may be arbitrarily specified.

  11. Intrapericardial denervation - Radial artery blood flow and heart rate responses to LBNP

    NASA Technical Reports Server (NTRS)

    Mckeever, Kenneth H.; Skidmore, Michael G.; Keil, Lanny C.; Sandler, Harold

    1990-01-01

    The effects of intrapericardial denervation on the radial artery blood flow velocity (RABFV) and heart rate (HR) responses to LBNP in rhesus monkeys were investigated by measuring the RABFV transcutaneously by a continuous-wave Doppler ultrasonic flowmeter in order to derive an index of forearm blood flow response to low (0 to -20 mm Hg) and high (0 to -60 mm Hg) ramp exposures during supine LBNP. Four of the eight subjects were subjected to efferent and afferent cardiac denervation. It was found that, during low levels of LBNP, monkeys with cardiac denervation exhibited no cardiopulmonary baroreceptor-mediated change in the RABFV or HR, unlike the intact animals, which showed steady decreases in RABFV during both high- and low-pressure protocols. It is suggested that forearm blood flow and HR responses to low-level LBNP, along with pharmacological challenge, are viable physiological tests for verifying the completeness of atrial and cardiopulmonary baroreceptor denervation.

  12. An analytical solution for transient radial flow through unsaturated fractured porous media

    SciTech Connect

    Wu, Yu-Shu; Pan, Lehua

    2004-02-13

    This paper presents analytical solutions for one-dimensional radial transient flow through horizontal, unsaturated fractured rock formation. In these solutions, unsaturated flow through fractured media is described by a linearized Richards' equation, while fracture-matrix interaction is handled using the dual-continuum concept. Although linearizing Richards' equation requires a specially correlated relationship between relative permeability and capillary pressure functions for both fractures and matrix, these specially formed relative permeability and capillary pressure functions are still physically meaningful. These analytical solutions can thus be used to describe the transient behavior of unsaturated flow in fractured media under the described model conditions. They can also be useful in verifying numerical simulation results, which, as demonstrated in this paper, are otherwise difficult to validate.

  13. Estimating vertical velocity and radial flow from Doppler radar observations of tropical cyclones

    NASA Astrophysics Data System (ADS)

    Lee, J. L.; Lee, W. C.; MacDonald, A. E.

    2006-01-01

    The mesoscale vorticity method (MVM) is used in conjunction with the ground-based velocity track display (GBVTD) to derive the inner-core vertical velocity from Doppler radar observations of tropical cyclone (TC) Danny (1997). MVM derives the vertical velocity from vorticity variations in space and in time based on the mesoscale vorticity equation. The use of MVM and GBVTD allows us to derive good correlations among the eye-wall maximum wind, bow-shaped updraught and echo east of the eye-wall in Danny. Furthermore, we demonstrate the dynamically consistent radial flow can be derived from the vertical velocity obtained from MVM using the wind decomposition technique that solves the Poisson equations over a limited-area domain. With the wind decomposition, we combine the rotational wind which is obtained from Doppler radar wind observations and the divergent wind which is inferred dynamically from the rotational wind to form the balanced horizontal wind in TC inner cores, where rotational wind dominates the divergent wind. In this study, we show a realistic horizontal and vertical structure of the vertical velocity and the induced radial flow in Danny's inner core. In the horizontal, the main eye-wall updraught draws in significant surrounding air, converging at the strongest echo where the maximum updraught is located. In the vertical, the main updraught tilts vertically outwards, corresponding very well with the outward-tilting eye-wall. The maximum updraught is located at the inner edge of the eye-wall clouds, while downward motions are found at the outer edge. This study demonstrates that the mesoscale vorticity method can use high-temporal-resolution data observed by Doppler radars to derive realistic vertical velocity and the radial flow of TCs. The vorticity temporal variations crucial to the accuracy of the vorticity method have to be derived from a high-temporal-frequency observing system such as state-of-the-art Doppler radars.

  14. Coal slurry fuel supply and purge system

    DOEpatents

    McDowell, Robert E.; Basic, Steven L.; Smith, Russel M.

    1994-01-01

    A coal slurry fuel supply and purge system for a locomotive engines is disclosed which includes a slurry recirculation path, a stand-by path for circulating slurry during idle or states of the engine when slurry fuel in not required by the engine, and an engine header fluid path connected to the stand-by path, for supplying and purging slurry fuel to and from fuel injectors. A controller controls the actuation of valves to facilitate supply and purge of slurry to and from the fuel injectors. A method for supplying and purging coal slurry in a compression ignition engine is disclosed which includes controlling fluid flow devices and valves in a plurality of fluid paths to facilitate continuous slurry recirculation and supply and purge of or slurry based on the operating state of the engine.

  15. Radial flow fuel nozzle for a combustor of a gas turbine

    DOEpatents

    Means, Gregory Scott; Boardman, Gregory Allen; Berry, Jonathan Dwight

    2016-07-05

    A combustor for a gas turbine generally includes a radial flow fuel nozzle having a fuel distribution manifold, and a fuel injection manifold axially separated from the fuel distribution manifold. The fuel injection manifold generally includes an inner side portion, an outer side portion, and a plurality of circumferentially spaced fuel ports that extend through the outer side portion. A plurality of tubes provides axial separation between the fuel distribution manifold and the fuel injection manifold. Each tube defines a fluid communication path between the fuel distribution manifold and the fuel injection manifold.

  16. Proton/pion ratios and radial flow in pp and peripheral heavy ion collisions

    NASA Astrophysics Data System (ADS)

    Cuautle, E.; Paić, G.

    2006-09-01

    The production of baryon and mesons in the RHIC heavy-ion experiments has received a lot of attention lately. Although not widely known, the pp data measured concurrently with heavy ion collisions do not find a convincing explanation in terms of simple models. We present the results of an afterburner to Pythia and Hijing event generators, simulating radial flow which seems to qualitatively explain the experimental results when applied to the pp collision data from RHIC at 200 GeV center-of-mass energy.

  17. Proton/pion ratios and radial flow in pp and peripheral heavy ion collisions

    SciTech Connect

    Cuautle, E.; Paic, G.

    2006-09-25

    The production of baryon and mesons in the RHIC heavy-ion experiments has received a lot of attention lately. Although not widely known, the pp data measured concurrently with heavy ion collisions do not find a convincing explanation in terms of simple models. We present the results of an afterburner to Pythia and Hijing event generators, simulating radial flow which seems to qualitatively explain the experimental results when applied to the pp collision data from RHIC at 200 GeV center-of-mass energy.

  18. Why is the radial flow in central pA collisions stronger than in AA?

    NASA Astrophysics Data System (ADS)

    Kalaydzhyan, Tigran; Shuryak, Edward

    2014-11-01

    Both the transverse size and entropy density per area in central pA collisions is smaller than in central AA, and yet the radial flow is stronger. We propose an explanation to this puzzle. Using a weak attraction between strings through the σ-meson exchange, fitted to the lattice data, we find collective implosion of the "spaghetti" multi-string state. Collectivization of the sigma field of the strings is the QCD analog of the black hole formation occurring in holographic models.

  19. Single stage high pressure centrifugal slurry pump

    DOEpatents

    Meyer, John W.; Bonin, John H.; Daniel, Arnold D.

    1984-03-27

    Apparatus is shown for feeding a slurry to a pressurized housing. An impeller that includes radial passages is mounted in the loose fitting housing. The impeller hub is connected to a drive means and a slurry supply means which extends through the housing. Pressured gas is fed into the housing for substantially enveloping the impeller in a bubble of gas.

  20. Flow mechanism of Forchheimer's cubic equation in high-velocity radial gas flow through porous media

    SciTech Connect

    Ezeudembah, A.S.; Dranchuk, P.M.

    1982-01-01

    Formal derivation of Forchheimer's cubic equation is made by considering the kinetic energy equation of mean flow and dimensional relations for one-dimensional, linear, incompressible fluid flow. By the addition of the cubic term, this equation is regarded as a modified Forchheimer's quadratic equation which accounts for the flow rates obtained beyond the laminar flow condition. The cubic equation spans a wide range of flow rates and regimes. For suitable use in gas flow studies, this equation has been adapted, modified, and corrected for the gas slippage effect. The physical basis of the cubic term has been established by using boundary layer theory to explain the high-velocity, high-pressure flow behavior through a porous path. Gamma, the main parameter in the cubic term, is related directly to a characteristic, dimensionless shape factor which is significant at higher flow rates. It is inversely related to viscosity, but has no dependence on the gas slippage coefficient in the higher flow regime. 25 references.

  1. Eigenmodes of Ducted Flows With Radially-Dependent Axial and Swirl Velocity Components

    NASA Technical Reports Server (NTRS)

    Kousen, Kenneth A.

    1999-01-01

    This report characterizes the sets of small disturbances possible in cylindrical and annular ducts with mean flow whose axial and tangential components vary arbitrarily with radius. The linearized equations of motion are presented and discussed, and then exponential forms for the axial, circumferential, and time dependencies of any unsteady disturbances are assumed. The resultant equations form a generalized eigenvalue problem, the solution of which yields the axial wavenumbers and radial mode shapes of the unsteady disturbances. Two numerical discretizations are applied to the system of equations: (1) a spectral collocation technique based on Chebyshev polynomial expansions on the Gauss-Lobatto points, and (2) second and fourth order finite differences on uniform grids. The discretized equations are solved using a standard eigensystem package employing the QR algorithm. The eigenvalues fall into two primary categories: a discrete set (analogous to the acoustic modes found in uniform mean flows) and a continuous band (analogous to convected disturbances in uniform mean flows) where the phase velocities of the disturbances correspond to the local mean flow velocities. Sample mode shapes and eigensystem distributions are presented for both sheared axial and swirling flows. The physics of swirling flows is examined with reference to hydrodynamic stability and completeness of the eigensystem expansions. The effect of assuming exponential dependence in the axial direction is discussed.

  2. Effect of Radial Density Configuration on Wave Field and Energy Flow in Axially Uniform Helicon Plasma

    NASA Astrophysics Data System (ADS)

    Chang, Lei; Li, Qingchong; Zhang, Huijie; Li, Yinghong; Wu, Yun; Zhang, Bailing; Zhuang, Zhong

    2016-08-01

    The effect of the radial density configuration in terms of width, edge gradient and volume gradient on the wave field and energy flow in an axially uniform helicon plasma is studied in detail. A three-parameter function is employed to describe the density, covering uniform, parabolic, linear and Gaussian profiles. It finds that the fraction of power deposition near the plasma edge increases with density width and edge gradient, and decays in exponential and “bump-on-tail” profiles, respectively, away from the surface. The existence of a positive second-order derivative in the volume density configuration promotes the power deposition near the plasma core, which to our best knowledge has not been pointed out before. The transverse structures of wave field and current density remain almost the same during the variation of density width and gradient, confirming the robustness of the m=1 mode observed previously. However, the structure of the electric wave field changes significantly from a uniform density configuration, for which the coupling between the Trivelpiece-Gould (TG) mode and the helicon mode is very strong, to non-uniform ones. The energy flow in the cross section of helicon plasma is presented for the first time, and behaves sensitive to the density width and edge gradient but insensitive to the volume gradient. Interestingly, the radial distribution of power deposition resembles the radial profile of the axial component of current density, suggesting the control of the power deposition profile in the experiment by particularly designing the antenna geometry to excite a required axial current distribution. supported by National Natural Science Foundation of China (No. 11405271)

  3. A PC-based inverse design method for radial and mixed flow turbomachinery

    NASA Technical Reports Server (NTRS)

    Skoe, Ivar Helge

    1991-01-01

    An Inverse Design Method suitable for radial and mixed flow turbomachinery is presented. The codes are based on the streamline curvature concept; therefore, it is applicable for current personal computers from the 286/287 range. In addition to the imposed aerodynamic constraints, mechanical constraints are imposed during the design process to ensure that the resulting geometry satisfies production consideration and that structural considerations are taken into account. By the use of Bezier Curves in the geometric modeling, the same subroutine is used to prepare input for both aero and structural files since it is important to ensure that the geometric data is identical to both structural analysis and production. To illustrate the method, a mixed flow turbine design is shown.

  4. Evidence for Radial Flow of Thermal Dileptons in High-Energy Nuclear Collisions

    SciTech Connect

    Arnaldi, R.; Colla, A.; Cortese, P.; Ferretti, A.; Oppedisano, C.; Scomparin, E.; Banicz, K.; Damjanovic, S.; Castor, J.; Devaux, A.; Fargeix, J.; Force, P.; Manso, F.; Chaurand, B.; Cicalo, C.; Falco, A. de; Floris, M.; Masoni, A.; Puddu, G.; Serci, S.

    2008-01-18

    The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158A GeV In-In collisions. An excess of pairs above the known meson decays has been reported before. We now present precision results on the associated transverse momentum spectra. The slope parameter T{sub eff} extracted from the spectra rises with dimuon mass up to the {rho}, followed by a sudden decline above. While the initial rise is consistent with the expectations for radial flow of a hadronic decay source, the decline signals a transition to an emission source with much smaller flow. This may well represent the first direct evidence for thermal radiation of partonic origin in nuclear collisions.

  5. Radially dependent large-scale dynamos in global cylindrical shear flows and the local cartesian limit

    NASA Astrophysics Data System (ADS)

    Ebrahimi, F.; Blackman, E. G.

    2016-06-01

    For cylindrical differentially rotating plasmas, we study large-scale magnetic field generation from finite amplitude non-axisymmetric perturbations by comparing numerical simulations with quasi-linear analytic theory. When initiated with a vertical magnetic field of either zero or finite net flux, our global cylindrical simulations exhibit the magnetorotational instability (MRI) and large-scale dynamo growth of radially alternating mean fields, averaged over height and azimuth. This dynamo growth is explained by our analytic calculations of a non-axisymmetric fluctuation-induced electromotive force that is sustained by azimuthal shear of the fluctuating fields. The standard `Ω effect' (shear of the mean field by differential rotation) is unimportant. For the MRI case, we express the large-scale dynamo field as a function of differential rotation. The resulting radially alternating large-scale fields may have implications for angular momentum transport in discs and corona. To connect with previous work on large-scale dynamos with local linear shear and identify the minimum conditions needed for large-scale field growth, we also solve our equations in local Cartesian coordinates. We find that large-scale dynamo growth in a linear shear flow without rotation can be sustained by shear plus non-axisymmetric fluctuations - even if not helical, a seemingly previously unidentified distinction. The linear shear flow dynamo emerges as a more restricted version of our more general new global cylindrical calculations.

  6. Flow regimes in a vertical Taylor-Couette system with a radial thermal gradient

    NASA Astrophysics Data System (ADS)

    Guillerm, R.; Kang, C.; Savaro, C.; Lepiller, V.; Prigent, A.; Yang, K.-S.; Mutabazi, I.

    2015-09-01

    A rich variety of flow regimes in a Newtonian fluid inside a vertical large-aspect ratio and a wide-gap Taylor-Couette system with a radial temperature gradient has been determined in experiments and in direct numerical simulations (DNSs). Compared to previous experiments and numerical studies, a wider range of temperature differences (i.e., of the Grashof number Gr) and of the rotation rate (the Taylor number Ta) has been covered. The combined effect of rotation and of the radial temperature gradient is the occurrence of helicoidal vortices or modulated waves at the onset. Stationary axisymmetric vortices are found for very weak temperature differences. A good agreement was found for critical states between results from experiments, linear stability analysis, and DNS. Higher instability modes have been determined for a wide range of parameters and a state diagram of observable flow regimes has been established in the plane spanned by Gr and Ta. Some higher states observed in experiments were retrieved in DNS.

  7. NMR imaging and hydrodynamic analysis of neutrally buoyant non-Newtonian slurry flows

    SciTech Connect

    Bouillard, J.X.; Sinton, S.W.

    1995-02-01

    The flow of solids loaded suspension in cylindrical pipes has been the object of intense experimental and theoretical investigations in recent years. These types of flows are of great interest in chemical engineering because of their important use in many industrial manufacturing processes. Such flows are for example encountered in the manufacture of solid-rocket propellants, advanced ceramics, reinforced polymer composites, in heterogenous catalytic reactors, and in the pipeline transport of liquid-solids suspensions. In most cases, the suspension microstructure and the degree of solids dispersion greatly affect the final performance of the manufactured product. For example, solid propellant pellets need to be extremely-well dispersed in gel matrices for use as rocket engine solid fuels. The homogeneity of pellet dispersion is critical to allow good uniformity of the burn rate, which in turn affects the final mechanical performance of the engine. Today`s manufacturing of such fuels uses continuous flow processes rather than batch processes. Unfortunately, the hydrodynamics of such flow processes is poorly understood and is difficult to assess because it requires the simultaneous measurements of liquid/solids phase velocities and volume fractions. Due to the recent development in pulsed Fourier Transform NMR imaging, NMR imaging is now becoming a powerful technique for the non intrusive investigation of multi-phase flows. This paper reports and exposes a state-of-the-art experimental and theoretical methodology that can be used to study such flows. The hydrodynamic model developed for this study is a two-phase flow shear thinning model with standard constitutive fluid/solids interphase drag and solids compaction stresses. this model shows good agreement with experimental data and the limitations of this model are discussed.

  8. DEVELOPMENT OF A COMPUTATIONAL MULTIPHASE FLOW MODEL FOR FISCHER TROPSCH SYNTHESIS IN A SLURRY BUBBLE COLUMN REACTOR

    SciTech Connect

    Donna Post Guillen; Tami Grimmett; Anastasia M. Gribik; Steven P. Antal

    2011-12-01

    The Hybrid Energy Systems Testing (HYTEST) Laboratory at the Idaho National Laboratory was established to develop and test hybrid energy systems with the principal objective of reducing dependence on imported fossil fuels. A central component of the HYTEST is the slurry bubble column reactor (SBCR) in which the gas-to-liquid reactions are performed to synthesize transportation fuels using the Fischer Tropsch (FT) process. These SBCRs operate in the churn-turbulent flow regime, which is characterized by complex hydrodynamics, coupled with reacting flow chemistry and heat transfer. Our team is developing a research tool to aid in understanding the physicochemical processes occurring in the SBCR. A robust methodology to couple reaction kinetics and mass transfer into a four-field model (consisting of the bulk liquid, small bubbles, large bubbles and solid catalyst particles) consisting of thirteen species, which are CO reactant, H2 reactant, hydrocarbon product, and H2O product in small bubbles, large bubbles, and the bulk fluid plus catalyst is outlined. Mechanistic submodels for interfacial momentum transfer in the churn-turbulent flow regime are incorporated, along with bubble breakup/coalescence and two-phase turbulence submodels. The absorption and kinetic models, specifically changes in species concentrations, have been incorporated into the mass continuity equation. The reaction rate is based on the macrokinetic model for a cobalt catalyst developed by Yates and Satterfield. The model includes heat generation produced by the exothermic chemical reaction, as well as heat removal from a constant temperature heat exchanger. A property method approach is employed to incorporate vapor-liquid equilibrium (VLE) in a robust manner. Physical and thermodynamic properties as functions of changes in both pressure and temperature are obtained from VLE calculations performed external to the CMFD solver. The novelty of this approach is in its simplicity, as well as its

  9. Investigation of two-phase flow processes in coal slurry/hydrogen heaters. Final report

    SciTech Connect

    Sam, R.G.; Crowley, C.J.

    1986-08-01

    Experimental and analytical results are presented for two-phase slug flow in a horizontal, transparent pipe at large diameter (6.75 in.) at high gas density (20 times the density of air at atmospheric pressure) and at liquid viscosities ranging from 1 to 1000 centipoise. The test section replicates 1 1/2 rectangular coils (40 ft by 10 ft) of a fired heater in a coal liquefaction plant. Regime transtion, pressure drop, void fraction, and slug characteristic data have been obtained for liquid superficial velocities ranging from 0.2 to 6 ft/s and gas superficial velocities ranging from 0.2 to 12 ft/s. Regime transition results have been compared with the Taitel-Dukler analytical flow regime map. The transition from stratified to slug flow, which is underpredicted by the original analysis, has been studied in particular. Comparison with the dimensionless transition criterion (gas Froude number) shows that increased liquid viscosity increases the liquid level at which the transition occurs. Pressure drop data at the transition have been used to evaluate the interfacial shear and to show that it is greater than is assumed in the Taitel-Dukler analysis. Sensitivity studies for the transition criterion and interfacial shear illustrate exactly why the transition is underpredicted on the flow regime map and how the predictions can be improved. Photos of the flow patterns illustrate the mechanism of slug formation at high viscosity compared with low viscosity. Pressure drop, void fraction, and slug characteristic results are compared with an analysis for pressure drop in slug flow, demonstrating better predictive capability of this model at large pipe size, high gas density, and high viscosity, compared with correlations from the literature. The pressure drop model is also shown to be in excellent agreement with coal liquefaction pilot plant data. 34 refs.

  10. Width and rugosity of the topological plasma flow structures and their relation to the radial flights of particle tracers

    NASA Astrophysics Data System (ADS)

    García, L.; Llerena Rodríguez, I.; Carreras, B. A.

    2015-09-01

    An analysis of the distributions of the width and rugosity of topological plasma flow structures is presented for some resistive pressure-gradient-driven turbulence results. The distributions of the radial excursions of particle tracers during trappings are compared with those of the width and rugosity of the flow structures.

  11. Red blood cells radial dispersion in blood flowing through microchannels: The role of temperature.

    PubMed

    Pinho, Diana; Rodrigues, Raquel O; Faustino, Vera; Yaginuma, Tomoko; Exposto, José; Lima, Rui

    2016-07-26

    The behavior of suspensions of individual blood cells, such as red blood cells (RBCs), flowing through microvessels and microfluidic systems depend strongly on the hematocrit (Hct), microvessel topology and cell properties. Although it is well known that blood rheological properties are temperature dependent, to the best of our knowledge no work has studied the role of the temperature on the RBCs dispersion. A powerful way to investigate this latter effect is through a high-speed video microscopy system, which provides detailed flow measurements of each individual RBC. Hence, the effect of temperature on the RBCs dispersion flowing through a 100μm glass capillary was examined by means of a confocal micro-PTV system. Hundreds of labeled RBCs were tracked at moderate Hct (12%) and at four different temperatures, i.e., 25°C, 32°C, 37°C and 42°C. The results yielded an enhancement of the RBCs diffusion as the temperature increases. Hence, our findings show that RBCs radial dispersion is temperature dependent and as a result the temperature should not be ignored in future blood flow studies. We believe that this finding is important for a better understanding of blood mass transport mechanisms under both physiological and pathological conditions. PMID:26671221

  12. An interactive grid generation procedure for axial and radial flow turbomachinery

    NASA Technical Reports Server (NTRS)

    Beach, Timothy A.

    1989-01-01

    A combination algebraic/elliptic technique is presented for the generation of three dimensional grids about turbo-machinery blade rows for both axial and radial flow machinery. The technique is built around use of an advanced engineering workstation to construct several two dimensional grids interactively on predetermined blade-to-blade surfaces. A three dimensional grid is generated by interpolating these surface grids onto an axisymmetric grid. On each blade-to-blade surface, a grid is created using algebraic techniques near the blade to control orthogonality within the boundary layer region and elliptic techniques in the mid-passage to achieve smoothness. The interactive definition of bezier curves as internal boundaries is the key to simple construction. This procedure lends itself well to zonal grid construction, an important example being the tip clearance region. Calculations done to date include a space shuttle main engine turbopump blade, a radial inflow turbine blade, and the first stator of the United Technologies Research Center large scale rotating rig. A finite Navier-Stokes solver was used in each case.

  13. An interactive grid generation procedure for axial and radial flow turbomachinery

    NASA Astrophysics Data System (ADS)

    Beach, T. A.

    1990-01-01

    A combination algebraic/elliptic technique is presented for the generation of three dimensional grids about turbo-machinery blade rows for both axial and radial flow machinery. The technique is built around use of an advanced engineering workstation to construct several two dimensional grids interactively on predetermined blade-to-blade surfaces. A three dimensional grid is generated by interpolating these surface grids onto an axisymmetric grid. On each blade-to-blade surface, a grid is created using algebraic techniques near the blade to control orthogonality within the boundary layer region and elliptic techniques in the mid-passage to achieve smoothness. The interactive definition of bezier curves as internal boundaries is the key to simple construction. This procedure lends itself well to zonal grid construction, an important example being the tip clearance region. Calculations done to date include a space shuttle main engine turbopump blade, a radial inflow turbine blade, and the first stator of the United Technologies Research Center large scale rotating rig. A finite Navier-Stokes solver was used in each case.

  14. Radial-radial single rotor turbine

    DOEpatents

    Platts, David A.

    2006-05-16

    A rotor for use in turbine applications has a radial compressor/pump having radially disposed spaced apart fins forming passages and a radial turbine having hollow turbine blades interleaved with the fins and through which fluid from the radial compressor/pump flows. The rotor can, in some applications, be used to produce electrical power.

  15. Three-dimensional flow in radial turbomachinery and its impact on design

    NASA Technical Reports Server (NTRS)

    Tan, Choon S.; Hawthorne, William

    1993-01-01

    In the two papers on the 'Theory of Blade Design for Large Deflections' published in 1984, a new inverse design technique was presented for designing the shape of turbomachinery blades in three-dimensional flow. The technique involves the determination of the blade profile from the specification of a distribution of the product of the radius and the pitched averaged tangential velocity (i.e., r bar-V(sub theta), the mean swirl schedule) within the bladed region. This is in contrast to the conventional inverse design technique for turbomachinery blading in two dimensional flow in which the blade surface pressure or velocity distribution is specified and the blade profile determined as a result; this is feasible in two-dimensional flow because the streamlines along the blade surfaces are known a priori. However, in three-dimensional flow, the stream surface is free to deform within the blade passage so that the streamlines on the blade surfaces are not known a priori; thus it is difficult and not so useful to prescribe the blade surface pressure or velocity distribution and determine the resulting blade profile. It therefore seems logical to prescribe the swirl schedule within the bladed region for designing a turbomachinery blade profile in three-dimensional flow. Furthermore, specifying r bar-V(sub theta) has the following advantages: (1) it is related to the circulation around the blade (i.e., it is an aerodynamic quantity); (2) the work done or extracted is approximately proportional to the overall change in r bar-V(sub theta) across a given blade row (Euler turbine equation); and (3) the rate of change of r bar-V(sub theta) along the mean streamline at the blade is related to the pressure jump across the blade and therefore the blade loading. Since the publications of those two papers, the technique has been applied to the design of a low speed as well as a high speed radial inflow turbine (for turbocharger applications) both of which showed definite

  16. Comparisons between seismic Earth structures and mantle flow models based on radial correlation functions.

    PubMed

    Jordan, T H; Puster, P; Glatzmaier, G A; Tackley, P J

    1993-09-10

    Three-dimensional numerical simulations were conducted of mantle convection in which flow through the transition zone is impeded by either a strong chemical change or an endothermic phase change. The temperature fields obtained from these models display a well-defined minimum in the vertical correlation length at or near the radius where the barrier is imposed, even when the fields were filtered to low angular and radial resolutions. However, evidence for such a feature is lacking in the shear-velocity models derived by seismic tomography. This comparison suggests that any stratification induced by phase or chemical changes across the mid-mantle transition zone has a relatively small effect on the large-scale circulation of mantle material. PMID:17745353

  17. Accurate evaluation of viscoelasticity of radial artery wall during flow-mediated dilation in ultrasound measurement

    NASA Astrophysics Data System (ADS)

    Sakai, Yasumasa; Taki, Hirofumi; Kanai, Hiroshi

    2016-07-01

    In our previous study, the viscoelasticity of the radial artery wall was estimated to diagnose endothelial dysfunction using a high-frequency (22 MHz) ultrasound device. In the present study, we employed a commercial ultrasound device (7.5 MHz) and estimated the viscoelasticity using arterial pressure and diameter, both of which were measured at the same position. In a phantom experiment, the proposed method successfully estimated the elasticity and viscosity of the phantom with errors of 1.8 and 30.3%, respectively. In an in vivo measurement, the transient change in the viscoelasticity was measured for three healthy subjects during flow-mediated dilation (FMD). The proposed method revealed the softening of the arterial wall originating from the FMD reaction within 100 s after avascularization. These results indicate the high performance of the proposed method in evaluating vascular endothelial function just after avascularization, where the function is difficult to be estimated by a conventional FMD measurement.

  18. Estimated Performance of Radial-Flow Exit Nozzles for Air in Chemical Equilibrium

    NASA Technical Reports Server (NTRS)

    Englert, Gerald W.; Kochendorfer, Fred D.

    1959-01-01

    The thrust, boundary-layer, and heat-transfer characteristics were computed for nozzles having radial flow in the divergent part. The working medium was air in chemical equilibrium, and the boundary layer was assumed to be all turbulent. Stagnation pressure was varied from 1 to 32 atmospheres, stagnation temperature from 1000 to 6000 R, and wall temperature from 1000 to 3000 R. Design pressure ratio was varied from 5 to 320, and operating pressure ratio was varied from 0.25 to 8 times the design pressure ratio. Results were generalized independent of divergence angle and were also generalized independent of stagnation pressure in the temperature range of 1000 to 3000 R. A means of determining the aerodynamically optimum wall angle is provided.

  19. Evaluating the Uncertainty of Regional Flow by Using Radial Basis Function Network and Bootstrap Methods

    NASA Astrophysics Data System (ADS)

    Kan, P.

    2011-12-01

    This study employs radial basis function network (RBFNN) to simulate regional runoff in the future climate condition in Taiwan and bootstrap sampling technique to evaluate uncertainties of RBFNN. The hydrological and meteorological data (such as rainfall, river flow) in northern area of Taiwan during 1981 to 1999 are adopted as the training dataset to RBFNN, in which the parameters of RBFNN are optimized with genetic algorithm (GA). Meanwhile, the bootstrap sampling technique is applied for uncertainty analysis of RBFNN. The simulated results show that RBFNN with GA simulating the regional runoff reveals good performance and corresponding uncertainty can be evaluated by the bootstrap sampling technique. The results also illustrate that selecting training datasets randomly and repeatedly can reduce the possibility of model over-fitting of RBFNN. The regional runoff in the future can be estimated into an interval representing the possibility of the runoff by the proposed approach.

  20. Experiments on Thermal Convection in Rotating Spherical Shells With Radial Gravity: The Geophysical Fluid Flow Cell

    NASA Technical Reports Server (NTRS)

    Hart, John E.

    1996-01-01

    Experiments designed to study the fluid dynamics of buoyancy driven circulations in rotating spherical shells were conducted on the United States Microgravity Laboratory 2 spacelab mission. These experiments address several aspects of prototypical global convection relevant to large scale motions on the Sun, Earth, and on the giant planets. The key feature is the consistent modeling of radially directed gravity in spherical geometry by using dielectric polarization forces. Imagery of the planforms of thermally driven flows for rapidly-rotating regimes shows an initial separation and eventual merger of equatorial and polar convection as the heating (i.e. the Rayleigh number) is increased. At low rotation rates, multiple-states of motion for the same external parameters were observed.

  1. Flow patterns in a slurry-bubble-column reactor under reaction conditions

    SciTech Connect

    Toselane, B.A.; Brown, D.M.; Zou, B.S.; Dudukovic, M.P.

    1995-12-31

    The gas and liquid radioactive tracer response curves obtained in an industrial bubble column reactor of height to diameter ratio of 10 are analyzed and the suitability of the axial dispersion model for interpretation of the results is discussed. The relationship between the tracer concentration distribution and measured detector response of the soluble gas tracer (Ar-41) is possibly dominated by the dissolved gas. The one dimensional axial dispersion model cannot match all the experimental observations well and the flow pattern of the undissolved gas cannot be determined with certainty.

  2. Aerodynamic design of turbomachinery blading in three-dimensional flow - An application to radial inflow turbines

    NASA Technical Reports Server (NTRS)

    Yang, Y. L.; Tan, C. S.; Hawthorne, W. R.

    1992-01-01

    A computational method, based on a theory for turbomachinery blading design in three-dimensional inviscid flow, is applied to a parametric design study of a radial inflow turbine wheel. As the method requires the specification of swirl distribution, a technique for its smooth generation within the blade region is proposed. Excellent agreements have been obtained between the computed results from this design method and those from direct Euler computations, demonstrating the correspondence and consistency between the two. The computed results indicate the sensitivity of the pressure distribution to a lean in the stacking axis and a minor alteration in the hub/shroud profiles. Analysis based on Navier-Stokes solver shows no breakdown of flow within the designed blade passage and agreement with that from design calculation; thus the flow in the designed turbine rotor closely approximates that of an inviscid one. These calculations illustrate the use of a design method coupled to an analysis tool for establishing guidelines and criteria for designing turbomachinery blading.

  3. Performance back-deduction from a loading to flow coefficient map: Application to radial turbine

    NASA Astrophysics Data System (ADS)

    Carbonneau, Xavier; Binder, Nicolas

    2012-12-01

    Radial turbine stages are often used for applications requiring off-design operation, as turbocharging for instance. The off-design ability of such stages is commonly analyzed through the traditional turbine map, plotting the reduced mass-flow against the pressure-ratio, for reduced-speed lines. However, some alternatives are possible, such as the flow-coefficient ( Ψ) to loading-coefficient ( φ) diagram where the pressure-ratio lines are actually straight lines, very convenient property to perform prediction. A robust method re-creating this map from a predicted Ψ-φ diagram is needed. Recent work has shown that this back-deduction quality, without the use of any loss models, depends on the knowledge of an intermediate pressure-ratio. A modelization of this parameter is then proposed. The comparison with both experimental and CFD results is presented, with quite good agreement for mass flow rate and rotational speed, and for the intermediate pressure ratio. The last part of the paper is dedicated to the application of the intermediate pressure-ratio knowledge to the improvement of the deduction of the pressure ratio lines in the Ψ-φ diagram. Beside this improvement, the back-deduction method of the classical map is structured, applied and evaluated.

  4. PIV investigation of the flow induced by a passive surge control method in a radial compressor

    NASA Astrophysics Data System (ADS)

    Guillou, Erwann; Gancedo, Matthieu; Gutmark, Ephraim; Mohamed, Ashraf

    2012-09-01

    Due to recent emission regulations, the use of turbochargers for force induction of internal combustion engines has increased. Actually, the trend in diesel engines is to downsize the engine by use of turbochargers that operate at higher pressure ratios. Unfortunately, increasing the impeller rotational speed of turbocharger radial compressors tends to reduce their range of operation, which is limited at low mass flow rate by the occurrence of surge. In order to extend the operability of turbochargers, compressor housings can be equipped with a passive surge control device such as a "ported shroud." This specific casing treatment has been demonstrated to enhance the surge margin with minor negative impact on the compressor efficiency. However, the actual working mechanisms of the system remain not well understood. Hence, in order to optimize the design of the ported shroud, it is crucial to identify the dynamic flow changes induced by the implementation of the device to control instabilities. From the full dynamic survey of the compressor performance characteristics obtained with and without ported shroud, specific points of operation were selected to carry out planar flow visualization. At normal working, both standard and stereoscopic particle imaging velocimetry (PIV) measurements were performed to evaluate instantaneous and mean velocity flow fields at the inlet of the compressor. At incipient and full surge, phase-locked PIV measurements were added. As a result, satisfying characterization of the compressor instabilities was provided at different operational speeds. Combining transient pressure data and PIV measurements, the time evolution of the complex flow patterns occurring at surge was reconstructed and a better insight into the bypass mechanism was achieved.

  5. The Potential Effects of a Biofeedback Writing Exercise on Radial Artery Blood Flow and Neck Mobility

    PubMed Central

    Krullaards, Rob L.; Pel, Johan J. M.; Snijders, Chris J.; Kleinrensink, Gert-Jan

    2009-01-01

    Background: It has been suggested that sustained contraction of the deep neck muscles may reduce axial cervical range of motion (CROM) and radial artery blood flow velocity (vrad.art.mean). No studies have reported both phenomena in relation to acute hand, shoulder or neck trauma. Procedures: The CROM and vrad.art.mean were measured in 20 police officers prior to and immediately after a 2-hours drive on a motorcycle and immediately after a 1-minute writing exercise using biofeedback. The CROM was measured using separate inclinometers and the vrad.art.mean was measured in both arms just proximal to the wrist using echo-Doppler. Findings: During the study, one officer had a motorcycle accident resulting in acute symptoms of neck trauma. His vrad.art.mean was acutely reduced by 73% (right arm) and 45% (left arm). Writing with biofeedback increased his vrad.art.mean by 150% (right arm) and 80% (left arm). In the remaining 19 officers, the CROM to the right was significantly increased after the 2-hours driving task (p<0.05; paired subject t-test). Writing with biofeedback increased their CROM in both directions and vrad.art.mean in both arms (p<001). Conclusions: A 2-hours drive showed modest physical changes in the upper extremities. Biofeedback in writing tasks might relate to the influence of relaxation and diverting attention for neck mobility and arterial blood flow improvement. PMID:23675136

  6. Travel time approach to kinetically sorbing solute by diverging radial flows through heterogeneous porous formations

    NASA Astrophysics Data System (ADS)

    Severino, Gerardo; de Bartolo, Samuele; Toraldo, Gerardo; Srinivasan, Gowri; Viswanathan, Hari

    2012-12-01

    Diverging radial flow takes place in a heterogeneous porous medium where the log conductivity Y = ln K is modeled as a stationary random space function (RSF). The flow is steady, and is generated by a fully penetrating well. A linearly sorbing solute is injected through the well envelope, and we aim at computing the average flux concentration (breakthrough curve). A relatively simple solution for this difficult problem is achieved by adopting, similar to Indelman and Dagan (1999), a few simplifying assumptions: (i) a thick aquifer of large horizontal extent, (ii) mildly heterogeneous medium, (iii) strongly anisotropic formation, and (iv) large Peclet number. By introducing an appropriate Lagrangian framework, three-dimensional transport is mapped onto a one-dimensional domain (τ, t) where τ and t represent the fluid travel and current time, respectively. Central for this approach is the probability density function of the RSF τthat is derived consistently with the adopted assumptions stated above. Based on this, it is shown that the travel time can be regarded as a Gaussian random variable only in the far field. The breakthrough curves are analyzed to assess the impact of the hydraulic as well as reactive parameters. Finally, the travel time approach is tested against a forced-gradient transport experiment and shows good agreement.

  7. Flow-Mediated Change in Viscoelastic Property of Radial Arterial Wall Measured by 22 MHz Ultrasound

    NASA Astrophysics Data System (ADS)

    Ikeshita, Kazuki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2009-07-01

    The endothelial dysfunction is considered to be an initial step in atherosclerosis. Additionally, it was reported that the smooth muscle, which constructs the media of the artery, changes its characteristics owing to atherosclerosis. Therefore, it is essential to develop a method of assessing the regional endothelial function and mechanical properties of the arterial wall. To evaluate the endothelial function, a conventional technique of measuring the transient change in the diameter of the brachial artery caused by flow-mediated dilation (FMD) after the release of avascularization is used. However, this method can not evaluate the mechanical properties of the wall. We previously developed a method for the simultaneous measurements of waveforms of radial strain and blood pressure in the radial artery. In this study, the viscoelasticity of the arterial wall was estimated from the measured stress-strain relationship using the least-squares method and the transient changes in the mechanical properties of the arterial wall ware revealed. From in vivo experimental results, the stress-strain relationship showed a hysteresis loop and viscoelasticity was estimated by the proposed method. The slope of the loop decreased owing to FMD, which resulted in the decrease in estimated elastic modulus. The increase in the area of the loop occurred after recirculation, which corresponds to the increase in the ratio of the loss modulus (depends on viscosity) to the elastic modulus when the Voigt model is assumed. In this study, the variance in estimates was evaluated by in vivo measurement for 10 min. The temporal decrease in static elasticity after recirculation due to FMD was much larger than the evaluated variance. These results show a potential of the proposed method for the thorough analysis of the transient change in viscoelasticity due to FMD.

  8. Tribological Properties Of Coal Slurries

    NASA Technical Reports Server (NTRS)

    Fusaro, Robert L.; Schrubens, Dale L.

    1988-01-01

    Report describes study of tribological properties of coal/methanol slurries with pin-on-disk tribometer. Coefficients of friction, rates of wear of steel pin, and morphological studies of worn surfaces conducted on pins and disks of AISI 440C HT stainless steel and M-50 tool steel, both used as bearing steels. Coal slurries considered as replacement fuels in terrestrial oil-burning facilities and possible fuels for future aircraft turbine engines. Rates of wear of metallic components through which slurries flow limit such practical applications.

  9. Study of Radially Varying Magnetic Field on Blood Flow through Catheterized Tapered Elastic Artery with Overlapping Stenosis

    NASA Astrophysics Data System (ADS)

    Nadeem, S.; Ijaz, S.

    2015-11-01

    A precise model has been developed for studying the influence of metallic nanoparticles on blood flow through catheterized tapered elastic arteries with radially varying magnetic field. The model is solved under the mild stenosis approximation by considering blood as viscous fluid. The influence of different flow parameters associated with this problem such as Hartmann number, nanoparticle volume fraction, Grashof number and heat source or sink parameter is analyzed by plotting the graphs of the wall shear stress, resistance impedance to blood flow and stream lines. The influence of the radially varying magnetic field on resistance impedance to flow is analyzed and it is observed that the significantly strong magnetic force tends to increase in resistance.

  10. Evaluation of Radial Flow Fluidized Filter (R3F) Followed by Microfiltration and Ultrafiltration Systems in Calimesa, California

    EPA Science Inventory

    U.S. EPA coordinated a field study with South Mesa Water Utility to look for treatment alternatives for California State Project Water in the small community of Calimesa, California. EPA evaluated the performance of a system comprised of Radial Flow Fluidized Filtration (R3f) fo...

  11. 1r2dinv: A finite-difference model for inverse analysis of two dimensional linear or radial groundwater flow

    USGS Publications Warehouse

    Bohling, G.C.; Butler, J.J., Jr.

    2001-01-01

    We have developed a program for inverse analysis of two-dimensional linear or radial groundwater flow problems. The program, 1r2dinv, uses standard finite difference techniques to solve the groundwater flow equation for a horizontal or vertical plane with heterogeneous properties. In radial mode, the program simulates flow to a well in a vertical plane, transforming the radial flow equation into an equivalent problem in Cartesian coordinates. The physical parameters in the model are horizontal or x-direction hydraulic conductivity, anisotropy ratio (vertical to horizontal conductivity in a vertical model, y-direction to x-direction in a horizontal model), and specific storage. The program allows the user to specify arbitrary and independent zonations of these three parameters and also to specify which zonal parameter values are known and which are unknown. The Levenberg-Marquardt algorithm is used to estimate parameters from observed head values. Particularly powerful features of the program are the ability to perform simultaneous analysis of heads from different tests and the inclusion of the wellbore in the radial mode. These capabilities allow the program to be used for analysis of suites of well tests, such as multilevel slug tests or pumping tests in a tomographic format. The combination of information from tests stressing different vertical levels in an aquifer provides the means for accurately estimating vertical variations in conductivity, a factor profoundly influencing contaminant transport in the subsurface. ?? 2001 Elsevier Science Ltd. All rights reserved.

  12. Flow Characterization and Dynamic Analysis of a Radial Compressor with Passive Method of Surge Control

    NASA Astrophysics Data System (ADS)

    Guillou, Erwann

    Due to recent emission regulations, the use of turbochargers for force induction of internal combustion engines has increased. Actually, the trend in diesel engines is to downsize the engine by use of turbochargers that operate at higher pressure ratio. Unfortunately, increasing the rotational speed tends to reduce the turbocharger radial compressor range of operation which is limited at low mass flow rate by the occurrence of surge. In order to extent the operability of turbochargers, compressor housings can be equipped with a passive surge control device also known as ported shroud. This specific casing treatment has been demonstrated to enhance surge margin with minor negative impact on the compressor efficiency. However, the actual working mechanisms of the bypass system remain not well understood. In order to optimize the design of the ported shroud, it is then crucial to identify the dynamic flow changes induced by the implementation of the device to control instabilities. Experimental methods were used to assess the development of instabilities from stable, stall and eventually surge regimes of a ported shroud centrifugal compressor. Systematic comparison was conducted with the same compressor design without ported shroud. Hence, the full pressure dynamic survey of both compressors' performance characteristics converged toward two different and probably interrelated driving mechanisms to the development and/or propagation of unsteadiness within each compressor. One related the pressure disturbances at the compressor inlet, and notably the more apparent development of perturbations in the non-ported compressor impeller, whereas the other was attributed to the pressure distortions induced by the presence of the tongue in the asymmetric design of the compressor volute. Specific points of operation were selected to carry out planar flow measurements. At normal working, both standard and stereoscopic particle imaging velocimetry (PIV) measurements were performed

  13. Experimental evaluation of connectivity influence on dispersivity under confined and unconfined radial convergent flow conditions

    NASA Astrophysics Data System (ADS)

    Guzzi, Silvia; Molinari, Antonio; Fallico, Carmine; Pedretti, Daniele

    2014-05-01

    Heterogeneity and connectivity have a significant impact on the fate and transport of contaminants due to the occurrence of formations with largest permeability than the surrounding geological materials, which can originate preferential pathways in groundwater system. These issues are usually addressed by tracer tests and a radial convergent (RC) flow setting is typically selected for convenience but more complicated for model interpretation than uniform flow transport. An experimental investigation was performed using RC tracer tests in a 3D intermediate scale physical model to illustrate the role of connected features on the estimation of dispersivity using the classical Sauty solution and the method of moments, under confined and unconfined aquifer conditions. The physical model consists of 26 piezometers located at difference distances from a constant-discharge central pumping well. The box is filled with gravel channels embedded in a sandy matrix and organized in different layers. Materials have been well characterized before and after the test. For the confined configuration, a silt layer was placed above the previous layers. Tracer tests were performed using potassium iodide solutions with concentration of 3•10-3 M and under a constant pumping flow rate of 0.05 L/s. To mimic a pulse injection in each piezometer we used syringes and pipes, whereas a probe allowed continuous measuring of tracer concentration. Average velocity and longitudinal dispersion coefficient were defined from the first and second central moment of the observed breakthrough curves for each piezometer (integrated over the outflow boundary of the domain) and using the classical curve matching from the Sauty's solution at different Péclet numbers. Results reveal in some cases that estimates of hydrodynamic parameters from the Sauty solution and the method of moments seem to be different. This is related to the different basic assumptions of the two methods applied, and especially because

  14. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of As, Cd, and Hg in cereals.

    PubMed

    Chen, Feng-Yi; Jiang, Shiuh-Jen

    2009-08-12

    A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of As, Cd, and Hg in cereals using flow injection chemical vapor generation (VG) as the sample introduction system. A slurry containing 6% m/v flour, 0.7% m/v thiourea, 0.4 microg mL(-1) Co(II), and 2.5% v/v HCl was injected into a VG-ICP-MS system for the determination of As, Cd, and Hg without dissolution and mineralization. Because the sensitivities of the elements studied in the slurry and that of aqueous solution were quite different, a standard addition method and an isotope dilution method were used for the determination of As, Cd, and Hg in selected cereal samples. The influences of vapor generation conditions and slurry preparation on the ion signals were reported. The effectiveness of the vapor generation sample introduction technique in alleviating various spectral interferences in ICP-MS analysis has been demonstrated. This method has been applied for the determination of As, Cd, and Hg in NIST SRM 1567a Wheat Flour reference material, NIST SRM 1568a Rice Flour reference material, and cereal samples obtained from local market. The As, Cd, and Hg analysis results of the reference materials agreed with the certified values. The method detection limits estimated from standard addition curves were about 0.10, 0.16, and 0.07 ng g(-1) for As, Cd, and Hg, respectively, in the original cereal samples. PMID:19606866

  15. Theoretical analysis of inertially irrotational and solenoidal flow in two-dimensional radial-flow pump and turbine impellers with equiangular blades

    NASA Astrophysics Data System (ADS)

    Visser, F. C.; Brouwers, J. J. H.; Badie, R.

    1994-06-01

    Using the theory of functions of a complex variable, in particular the method of conformal mapping, the irrotational and solenoidal flow in two-dimensional radial-flow pump and turbine impellers fitted with equiangular blades is analyzed. Exact solutions are given for the fluid velocity along straight radial pump and turbine impeller blades, while for logarithmic spiral pump impeller blades solutions are given which hold asymptotically as (r(sub 1)/r(sub 2))(exp n) approaches 0, in which r(sub 1) is impeller inner radius, r(sub 2) is impeller outer radius, and n is the number of blades. Both solutions are given in terms of a Fourier series, with the Fourier coefficients being given by the (Gauss) hypergeometric function and the beta function respectively. The solutions are used to derive analytical expressions for a number of parameters which are important for practical design of radial turbomachinery, and which reflect the two-dimensional nature of the flow field. Parameters include rotational slip of the flow leaving radial impellers, conditions to avoid reverse flow between impeller blades, and conditions for shockless flow at impeller entry, with the number of blades and blade curvature as variables. Furthermore, analytical extensions to classical one-dimensional Eulerian-based expressions for developed head of pumps and delivered work of turbines are given.

  16. A Miniature Radial-Flow Wind Turbine Using Piezoelectric Transducers and Magnetic Excitation

    NASA Astrophysics Data System (ADS)

    Fu, H.; Yeatman, E. M.

    2015-12-01

    This paper presents a miniature radial-flow piezoelectric wind turbine for harvesting airflow energy. The turbine's transduction is achieved by magnetic “plucking”of a piezoelectric beam by the passing rotor. The magnetic coupling is formed by two magnets on the beam's free end and on the rotor plate. Frequency up-conversion is realized by the magnetic excitation, allowing the rotor to rotate at any low frequency while the beam can vibrate at its resonant frequency after each plucking. The operating range of the device is, therefore, expanded by this mechanism. Two arrangements of magnetic orientation have been investigated, showing that the repulsive arrangement has higher output power. The influence of the vertical gap between magnets was also examined, providing guidance for the final design. A prototype was built and tested in a wind tunnel. A peak power output of 159 μW was obtained with a 270 kΩ load at 2.7 m/s airflow speed. The device started working at 3.5 m/s and kept operating when the airflow speed fell to 1.84 m/s.

  17. Linear stability of a circular Couette flow under a radial thermoelectric body force

    NASA Astrophysics Data System (ADS)

    Yoshikawa, H. N.; Meyer, A.; Crumeyrolle, O.; Mutabazi, I.

    2015-03-01

    The stability of the circular Couette flow of a dielectric fluid is analyzed by a linear perturbation theory. The fluid is confined between two concentric cylindrical electrodes of infinite length with only the inner one rotating. A temperature difference and an alternating electric tension are applied to the electrodes to produce a radial dielectrophoretic body force that can induce convection in the fluid. We examine the effects of superposition of this thermoelectric force with the centrifugal force including its thermal variation. The Earth's gravity is neglected to focus on the situations of a vanishing Grashof number such as microgravity conditions. Depending on the electric field strength and of the temperature difference, critical modes are either axisymmetric or nonaxisymmetric, occurring in either stationary or oscillatory states. An energetic analysis is performed to determine the dominant destabilizing mechanism. When the inner cylinder is hotter than the outer one, the circular Couette flow is destabilized by the centrifugal force for weak and moderate electric fields. The critical mode is steady axisymmetric, except for weak fields within a certain range of the Prandtl number and of the radius ratio of the cylinders, where the mode is oscillatory and axisymmetric. The frequency of this oscillatory mode is correlated with a Brunt-Väisälä frequency due to the stratification of both the density and the electric permittivity of the fluid. Under strong electric fields, the destabilization by the dielectrophoretic force is dominant, leading to oscillatory nonaxisymmetric critical modes with a frequency scaled by the frequency of the inner-cylinder rotation. When the outer cylinder is hotter than the inner one, the instability is again driven by the centrifugal force. The critical mode is axisymmetric and either steady under weak electric fields or oscillatory under strong electric fields. The frequency of the oscillatory mode is also correlated with the

  18. Approximate theory for radial filtration/consolidation

    SciTech Connect

    Tiller, F.M.; Kirby, J.M.; Nguyen, H.L.

    1996-10-01

    Approximate solutions are developed for filtration and subsequent consolidation of compactible cakes on a cylindrical filter element. Darcy`s flow equation is coupled with equations for equilibrium stress under the conditions of plane strain and axial symmetry for radial flow inwards. The solutions are based on power function forms involving the relationships of the solidosity {epsilon}{sub s} (volume fraction of solids) and the permeability K to the solids effective stress p{sub s}. The solutions allow determination of the various parameters in the power functions and the ratio k{sub 0} of the lateral to radial effective stress (earth stress ratio). Measurements were made of liquid and effective pressures, flow rates, and cake thickness versus time. Experimental data are presented for a series of tests in a radial filtration cell with a central filter element. Slurries prepared from two materials (Microwate, which is mainly SrSO{sub 4}, and kaolin) were used in the experiments. Transient deposition of filter cakes was followed by static (i.e., no flow) conditions in the cake. The no-flow condition was accomplished by introducing bentonite which produced a nearly impermeable layer with negligible flow. Measurement of the pressure at the cake surface and the transmitted pressure on the central element permitted calculation of k{sub 0}.

  19. The origins of radial fracture systems and associated large lava flows on Venus

    NASA Technical Reports Server (NTRS)

    Parfitt, Elisabeth A.; Wilson, Lionel; Head, James W., III

    1992-01-01

    Magellan images have revealed the existence of systems of radial fractures on venus that are very similar in form to terrestrial dike swarms such as the Mackenzie swarm in Northern Canada. The association of many of the fracture systems with lava flows, calderas, and volcanic edifices further support the idea of a dike emplacement origin. A global survey of the Magellan images has allowed the location of 300 such fracture systems. Two types of fracture systems are defined. A series of models were developed to simulate the emplacement of dikes on Venus. Observations of fracture lengths and widths were then used to constrain the emplacement conditions. The model results show that the great length and relatively large width of the fractures can only be explained if the dikes that produce them were emplaced in high driving pressure (pressure buffered) conditions. Such conditions imply high rates of melt production, which is consistent with the melt being derived directly from a plume head. We have recently modeled the vertical emplacement of a dike from the top of a mantle plume and calculated the eruption rates such a dike would produce on reaching the surface. This modeling shows that eruption rates of approximately 0.1 cu km/hr can readily be generated by such a dike, consistent with the above results. However, the sensitivity of the model to dike width and therefore driving pressure means that eruption rates from dikes emplaced from the base of the crust or the head of a mantle plume could be orders of magnitude higher than this. Clearly, therefore, the model needs to be refined in order to better constrain eruption conditions. However, it is worth noting here that the initial results do show that even for moderate dike widths, eruption rates could be at least on the order of those estimated for terrestrial flood basalts.

  20. Investigations of Particle Velocities in a Slurry Pump Using PIV. Part 1; The Tongue and Adjacent Channel Flow

    NASA Technical Reports Server (NTRS)

    Kadambi, Jaikrishnan R.; Charoenngam, Pathom; Subramanian, Amirthaganesh; Wernet, Mark P.; Sankovic, John M.; Addie, Graeme; Courtwright, Robert

    2004-01-01

    Transport of solid-liquid slurries in pipeline transport over short and medium distances is very important in many industries, including mining related processes. The particle image velocimetry technique was successfully utilized to investigate the velocities and kinetic energy fluctuations of slurry particles at the tongue region of an optically-clear centrifugal pump. The experiments were conducted using 500 micron glass beads at volumetric Concentrations of 2.5% and 5% and at pump speeds of 725 rpm and 1000 rpm. The fluctuation kinetic energy increased approximately 200% to 500% as the pump speed was increased from 725 rpm to IO00 rpm. The directional impingement mechanism is more significant at the pressure side of the blade, tongue and the casing. This mechanism becomes more important as the speed increases. This suggests that the impeller; tongue and the casing of the slurry pump can wear out quickly, especially with an increase in speed. In this paper the emphasis is on the tongue region. The random impingement mechanism caused by the fluctuation kinetic energy of the solids can play an important role on the erosion of the tongue area.

  1. Self-Organization in Granular Slurries

    NASA Astrophysics Data System (ADS)

    Ottino, Julio M.; Jain, Nitin; Lueptow, Richard M.; Khakhar, Devang V.

    2000-11-01

    Mixtures of tumbled granular materials under flow exhibit various intriguing types of un-mixing or self-organization. Small differences in particles' density, size or shape may trigger the effect. Nearly all studies to date have addressed the case of dry granular media, where the interparticle fluid is typically air. Here we report the existence of self-organization in wet granular media or slurries, mixtures of particles of different sizes dispersed in a lower density liquid. Technological examples appear in cement, ceramics, fine chemicals, and in the food industry; examples in nature appear in evolution of landslides and transport in river sediments. In spite of significantly different physics at the particle level, both axial banding (alternating bands rich in small and large particles in a long rotating cylinder) and radial segregation (in quasi 2D containers) are observed in slurries. However, axial segregation is significantly faster and the spectrum of outcomes is richer. Moreover, experiments with suitable fluids, reveal, for the first time, the internal structure of axially segregated systems, something that up to now has been accessible only via magnetic resonance imaging (MRI) experimentation.

  2. Aerothermal investigations of mixing flow phenomena in case of radially inclined ejection holes at the leading edge

    SciTech Connect

    Bohn, D.E.; Kusterer, K.A.

    2000-04-01

    A leading edge cooling configuration is investigated numerically by application of a three-dimensional conjugate fluid flow and heat transfer solver, CHT-flow. The code has been developed at the Institute of Steam and Gas Turbines, Aachen University of Technology. It works on the basis of an implicit finite volume method combined with a multi-block technique. The cooling configuration is an axial turbine blade cascade with leading edge ejection through two rows of cooling holes. The rows are located in the vicinity of the stagnation line, one row on the suction side, the other row is on the pressure side. the cooling holes have a radial ejection angle of 45 degrees. This configuration has been investigated experimentally by other authors and the results have been documented as a test case for numerical calculations of ejection flow phenomena. The numerical investigations focus on the aerothermal mixing process in the cooling jets and the impact on the temperature distribution on the blade surface. The radial ejection angles lead to a fully three-dimensional and asymmetric jet flow field. Within a secondary flow analysis, the cooling fluid jets are investigated in detail. The secondary flow fields include asymmetric kidney vortex systems with one dominating vortex on the back side of the jets. The numerical and experimental data show a respectable agreement concerning the vortex development.

  3. Characterization of azimuthal and radial velocity fields induced by rotors in flows with a low Reynolds number

    NASA Astrophysics Data System (ADS)

    Köhler, J.; Friedrich, J.; Ostendorf, A.; Gurevich, E. L.

    2016-02-01

    We theoretically and experimentally investigate the flow field that emerges from a rodlike microrotor rotating about its center in a nonaxisymmetric manner. A simple theoretical model is proposed that uses a superposition of two rotlets as a fundamental solution to the Stokes equation. The predictions of this model are compared to measurements of the azimuthal and radial microfluidic velocity field components that are induced by a rotor composed of fused microscopic spheres. The rotor is driven magnetically and the fluid flow is measured with the help of a probe particle fixed by an optical tweezer. We find considerable deviations of the mere azimuthal flow pattern induced by a single rotating sphere as it has been reported by Di Leonardo et al. [Phys. Rev. Lett. 96, 134502 (2006), 10.1103/PhysRevLett.96.134502]. Notably, the presence of a radial velocity component that manifests itself by an oscillation of the probe particle with twice the rotor frequency is observed. These findings open up a way to discuss possible radial transport in microfluidic devices.

  4. Characterization of azimuthal and radial velocity fields induced by rotors in flows with a low Reynolds number.

    PubMed

    Köhler, J; Friedrich, J; Ostendorf, A; Gurevich, E L

    2016-02-01

    We theoretically and experimentally investigate the flow field that emerges from a rodlike microrotor rotating about its center in a nonaxisymmetric manner. A simple theoretical model is proposed that uses a superposition of two rotlets as a fundamental solution to the Stokes equation. The predictions of this model are compared to measurements of the azimuthal and radial microfluidic velocity field components that are induced by a rotor composed of fused microscopic spheres. The rotor is driven magnetically and the fluid flow is measured with the help of a probe particle fixed by an optical tweezer. We find considerable deviations of the mere azimuthal flow pattern induced by a single rotating sphere as it has been reported by Di Leonardo et al. [Phys. Rev. Lett. 96, 134502 (2006)]. Notably, the presence of a radial velocity component that manifests itself by an oscillation of the probe particle with twice the rotor frequency is observed. These findings open up a way to discuss possible radial transport in microfluidic devices. PMID:26986414

  5. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of trace Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions.

    PubMed

    Chen, Wei-Ni; Jiang, Shiuh-Jen; Chen, Yen-Ling; Sahayam, A C

    2015-02-20

    A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions using flow injection (FI) vapor generation (VG) as the sample introduction system. A slurry containing 2% m/v lotion, 2% m/v thiourea, 0.05% m/v L-cysteine, 0.5 μg mL(-1) Co(II), 0.1% m/v Triton X-100 and 1.2% v/v HCl was injected into a VG-ICP-MS system for the determination of Ge, As, Cd, Sb, Hg and Bi without dissolution and mineralization. Because the sensitivities of the analytes in the slurry and that of aqueous solution were quite different, an isotope dilution method and a standard addition method were used for the determination. This method has been validated by the determination of Ge, As, Cd, Sb, Hg and Bi in GBW09305 Cosmetic (Cream) reference material. The method was also applied for the determination of Ge, As, Cd, Sb, Hg and Bi in three cosmetic lotion samples obtained locally. The analysis results of the reference material agreed with the certified value and/or ETV-ICP-MS results. The detection limit estimated from the standard addition curve was 0.025, 0.1, 0.2, 0.1, 0.15, and 0.03 ng g(-1) for Ge, As, Cd, Sb, Hg and Bi, respectively, in original cosmetic lotion sample. PMID:25682241

  6. Process for heating coal-oil slurries

    DOEpatents

    Braunlin, W.A.; Gorski, A.; Jaehnig, L.J.; Moskal, C.J.; Naylor, J.D.; Parimi, K.; Ward, J.V.

    1984-01-03

    Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec[sup [minus]1]. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72. 29 figs.

  7. Process for heating coal-oil slurries

    DOEpatents

    Braunlin, Walter A.; Gorski, Alan; Jaehnig, Leo J.; Moskal, Clifford J.; Naylor, Joseph D.; Parimi, Krishnia; Ward, John V.

    1984-01-03

    Controlling gas to slurry volume ratio to achieve a gas holdup of about 0.4 when heating a flowing coal-oil slurry and a hydrogen containing gas stream allows operation with virtually any coal to solvent ratio and permits operation with efficient heat transfer and satisfactory pressure drops. The critical minimum gas flow rate for any given coal-oil slurry will depend on numerous factors such as coal concentration, coal particle size distribution, composition of the solvent (including recycle slurries), and type of coal. Further system efficiency can be achieved by operating with multiple heating zones to provide a high heat flux when the apparent viscosity of the gas saturated slurry is highest. Operation with gas flow rates below the critical minimum results in system instability indicated by temperature excursions in the fluid and at the tube wall, by a rapid increase and then decrease in overall pressure drop with decreasing gas flow rate, and by increased temperature differences between the temperature of the bulk fluid and the tube wall. At the temperatures and pressures used in coal liquefaction preheaters the coal-oil slurry and hydrogen containing gas stream behaves essentially as a Newtonian fluid at shear rates in excess of 150 sec.sup. -1. The gas to slurry volume ratio should also be controlled to assure that the flow regime does not shift from homogeneous flow to non-homogeneous flow. Stable operations have been observed with a maximum gas holdup as high as 0.72.

  8. Filtering reprecipitated slurry

    SciTech Connect

    Morrissey, M.F.

    1992-12-31

    As part of the Late Washing Demonstration at Savannah River Technology Center, Interim Waste Technology has filtered reprecipitated and non reprecipitated slurry with the Experimental Laboratory Filter (ELF) at TNX. Reprecipitated slurry generates higher permeate fluxes than non reprecipitated slurry. Washing reprecipitated slurry may require a defoamer because reprecipitation encourages foaming.

  9. Filtering reprecipitated slurry

    SciTech Connect

    Morrissey, M.F.

    1992-01-01

    As part of the Late Washing Demonstration at Savannah River Technology Center, Interim Waste Technology has filtered reprecipitated and non reprecipitated slurry with the Experimental Laboratory Filter (ELF) at TNX. Reprecipitated slurry generates higher permeate fluxes than non reprecipitated slurry. Washing reprecipitated slurry may require a defoamer because reprecipitation encourages foaming.

  10. Results from Evaluation of Representative ASME AG-1 Section FK Radial Flow Dimple Pleated HEPA Filters Under Elevated Conditions - 12002

    SciTech Connect

    Giffin, Paxton K.; Parsons, Michael S.; Rickert, Jaime G.; Waggoner, Charles A.

    2012-07-01

    The American Society of Mechanical Engineers (ASME) has recently added Section FK establishing requirements for radial flow HEPA filters to the Code on Nuclear Air and Gas Treatment (AG-1). Section FK filters are expected to be a major element in the HEPA filtration systems across the US Department of Energy (DOE) complex. Radial flow filters have been used in Europe for some time, however a limited amount of performance evaluation data exists with respect to these new AG-1 Section FK units. In consultation with a technical working group, the Institute for Clean Energy Technology (ICET) at Mississippi State University (MSU)has evaluated a series of representative AG-1 Section FK dimple pleated radial flow HEPA filters. The effects of elevated relative humidity and temperature conditions on these filters are particularly concerning. Results from the evaluation of Section FK filters under ambient conditions have been presented at the 2011 waste management conference. Additions to the previous test stand to enable high temperature and high humidity testing, a review of the equipment used, the steps taken to characterize the new additions, and the filter test results are presented in this study. Test filters were evaluated at a volumetric flow rate of 56.6 m{sup 3}/min (2000 cfm) and were challenged under ambient conditions with Alumina, Al(OH){sub 3}, until reaching a differential pressure of 1 kPa (4 in. w.c.), at which time the filters were tested, unchallenged with aerosol, at 54 deg. C (130 deg. F) for approximately 1 hour. At the end of that hour water was sprayed near the heat source to maximize vaporization exposing the filter to an elevated relative humidity up to 95%. Collected data include differential pressure, temperature, relative humidity, and volumetric flow rate versus time. (authors)

  11. Determination of As, Hg and Pb in herbs using slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry.

    PubMed

    Tai, Chia-Yi; Jiang, Shiuh-Jen; Sahayam, A C

    2016-02-01

    Analysis of herbs for As, Hg and Pb has been carried out using slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) with flow injection vapor generation. Slurry containing 0.5% m/v herbal powder, 0.1% m/v citric acid and 2% v/v HCl was injected into the VG-ICP-MS system for the determination of As, Hg and Pb that obviate dissolution and mineralization. Standard addition and isotope dilution methods were used for quantifications in selected herbal powders. This method has been validated by the determination of As, Hg and Pb in NIST standard reference materials SRM 1547 Peach Leaves and SRM 1573a Tomato Leaves. The As, Hg and Pb analysis results of the reference materials agreed with the certified values. The precision obtained by the reported procedure was better than 7% for all determinations. The detection limit estimated from standard addition curve was 0.008, 0.003, and 0.007 ng mL(-1) for As, Hg and Pb, respectively. PMID:26304347

  12. A comparison of the calculated and experimental off-design performance of a radial flow turbine

    NASA Technical Reports Server (NTRS)

    Tirres, Lizet

    1992-01-01

    Off design aerodynamic performance of the solid version of a cooled radial inflow turbine is analyzed. Rotor surface static pressure data and other performance parameters were obtained experimentally. Overall stage performance and turbine blade surface static to inlet total pressure ratios were calculated by using a quasi-three dimensional inviscid code. The off design prediction capability of this code for radial inflow turbines shows accurate static pressure prediction. Solutions show a difference of 3 to 5 points between the experimentally obtained efficiencies and the calculated values.

  13. A comparison of the calculated and experimental off-design performance of a radial flow turbine

    NASA Technical Reports Server (NTRS)

    Tirres, Lizet

    1991-01-01

    Off design aerodynamic performance of the solid version of a cooled radial inflow turbine is analyzed. Rotor surface static pressure data and other performance parameters were obtained experimentally. Overall stage performance and turbine blade surface static to inlet total pressure ratios were calculated by using a quasi-three dimensional inviscid code. The off design prediction capability of this code for radial inflow turbines shows accurate static pressure prediction. Solutions show a difference of 3 to 5 points between the experimentally obtained efficiencies and the calculated values.

  14. Multi-stage slurry system used for grinding and polishing materials

    DOEpatents

    Hed, P. Paul; Fuchs, Baruch A.

    2001-01-01

    A slurry system draws slurry from a slurry tank via one of several intake pipes, where each pipe has an intake opening at a different depth in the slurry. The slurry is returned to the slurry tank via a bypass pipe in order to continue the agitation of the slurry. The slurry is then diverted to a delivery pipe, which supplies slurry to a polisher. The flow of slurry in the bypass pipe is stopped in order for the slurry in the slurry tank to begin to settle. As the polishing continues, slurry is removed from shallower depths in order to pull finer grit from the slurry. When the polishing is complete, the flow in the delivery pipe is ceased. The flow of slurry in the bypass pipe is resumed to start agitating the slurry. In another embodiment, the multiple intake pipes are replaced by a single adjustable pipe. As the slurry is settling, the pipe is moved upward to remove the finer grit near the top of the slurry tank as the polishing process continues.

  15. A Galerkin finite-element flow model to predict the transient response of a radially symmetric aquifer

    USGS Publications Warehouse

    Reilly, Thomas E.

    1984-01-01

    A computer program developed to evaluate radial flow of ground water, such as at a pumping well, recharge basin, or injection well, is capable of simulating anisotropic, inhomogenous, confined, or pseudo-unconfined (constant saturated thickness) conditions. Results compare well with those calculated from published analytical and model solutions. The program is based on the Galerkin finite-element technique. A sample model run is presented to illustrate the use of the program; supplementary material provides the program listing as well as a sample problem data set and output. From the text and other material presented, one can use the program to predict drawdowns from pumping and ground-water buildups from recharge in a radially symmetric ground-water system.

  16. Full-scale cold-flow modelling of the SRC-I slurry fired heater at Creare, Inc. mixing and 1/sup 0/ downslope studies

    SciTech Connect

    Mehta, D.C.

    1984-05-01

    One of the major pieces of equipment in the SRC-I Demonstration Plant is the slurry fired heater. Because of the absence of any plant data at comparable combinations of operating severity, a cold-flow modelling experimental program was initiated at Creare, Inc. The first phase of the test program confirmed the fired heater design and established reliable boundaries of flow rates for proper operation of the fired heater. An experimental setup was designed and built at Creare to duplicate the piping arrangement and flow conditions of the fired heater. The pipe dimensions, flow rates, and fluid properties were selected to minimize areas of scale-up and extrapolation. This follow-up test program was developed to resolve concerns raised from the observations made in the first phase. Tests were conducted to establish the extent of mixing between the liquid carpet and the fast-moving liquid slugs above it. The other segment of the test program was designed to develop the flow regime and pressure drop data in the 1/sup 0/ downslope configuration. The results demonstrated a significant amount of mixing between the liquid carpet and the liquid slugs for water and the 400-cP fluid at the design flow conditions. The extent of mixing improved with increasing liquid and gas velocities and decreasing liquid viscosities. Adequate mixing was observed at liquid flow rates as low as 50% of the design flow conditions. Slug flow was observed at design conditions in the 1/sup 0/ downslope configuration. Although adequate mixing is expected in heater pipes, different techniques should be investigated to improve the extent of mixing, especially near the transition boundary. 4 references, 5 figures, 8 tables.

  17. A design methodology for a magnetorheological fluid damper based on a multi-stage radial flow mode

    NASA Astrophysics Data System (ADS)

    Liao, C. R.; Zhao, D. X.; Xie, L.; Liu, Q.

    2012-08-01

    In this paper, a magnetorheological (MR) fluid damper based on a multi-stage radial flow mode is put forward, compared with traditional ones with annular damping channel which are of low magnetic field utilization and high energy consumption. The equivalent magnetic circuit model is derived, along with the relation between the magnetic induction at the working gap and the exciting current in the field coils. The finite-element software ANYSY is used to analyze the distribution of the magnetic field in the MR valve. The flow differential equation for a MR fluid in radial flow is theoretically set up, and the numerical solution is validated by means of the Herschel-Bulkley constitutive model. A MR damper was designed and fabricated in Chongqing University in accordance with the technical requirements of a railway vehicle anti-yaw damper, and the force-displacement characteristic of the damper was tested with J95-I type shock absorber test-bed. The results show that the experimental damping forces are in good agreement with the analytical ones, and the methodology is believed to help predict the damping force of a MR damper.

  18. Onset of radial flow in p+p collisions

    SciTech Connect

    Jiang, Kun; Zhu, Yinying; Liu, Weitao; Chen, Hongfang; Li, Cheng; Ruan, Lijuan; Tang, Zebo; Xu, Zhangbu

    2015-02-23

    It has been debated for decades whether hadrons emerging from p+p collisions exhibit collective expansion. The signal of the collective motion in p+p collisions is not as clear as in heavy-ion collisions because of the low multiplicity and large fluctuation in p+p collisions. Tsallis Blast-Wave (TBW) model is a thermodynamic approach, introduced to handle the overwhelming correlation and fluctuation in the hadronic processes. We have systematically studied the identified particle spectra in p+p collisions from RHIC to LHC using TBW and found no appreciable radial flow in p+p collisions below √s = 900 GeV. At LHC higher energy of 7 TeV in p+p collisions, the radial flow velocity achieves an average of (β) = 0.320 ± 0.005. This flow velocity is comparable to that in peripheral (40-60%) Au+Au collisions at RHIC. In addition, breaking of the identified particle spectra mT scaling was also observed at LHC from a model independent test.

  19. Thermal stresses due to a uniform heat flow past a circular hole with a radial edge crack

    SciTech Connect

    Edmonds, G.F.

    1987-01-01

    The problem solved here is that of finding the stresses in an isotropic, linear, thermoelastic solid when a uniform heat flow is disturbed by the presence of an insulated circular hole with a radial edge crack. By superimposing a Mellin-transform solution of the equations of thermoelasticity on a Michell series solution the author reduces the problem to a pair of singular integral equations which are then solved numerically. The stress-intensity factors and crack-formation energies, quantities of interest to workers in fracture mechanics, are then calculated.

  20. Multi-stage slurry system used for grinding and polishing materials

    SciTech Connect

    Hed, P. Paul; Fuchs, Baruch A.

    2000-03-01

    A slurry system draws slurry from a slurry tank via one of several intake pipes, where each pipe has an intake opening at a different depth in the slurry. The slurry is returned to the slurry tank via a bypass pipe in order to continue the agitation of the slurry. The slurry is then diverted to a delivery pipe, which supplies slurry to a polisher. The flow of shiny in the bypass pipe is stopped in order for the slurry in the slurry tank to begin to settle. As the polishing continues, slurry is removed from shallower depths in order to pull finer grit from the slurry. When the polishing is complete, the flow in the delivery pipe is ceased. The flow of slurry in the bypass pipe is resumed to start agitating the slurry. In another embodiment, the multiple intake pipes are replaced by a single adjustable pipe. As the slurry is settling, the pipe is moved upward to remove the finer grit near the top of the slurry tank as the polishing process continues.

  1. Final Technical Report: Numerical and Experimental Investigation of Turbulent Transport Control via Shaping of Radial Plasma Flow Profiles

    SciTech Connect

    Schuster, Eugenio

    2014-05-02

    The strong coupling between the different physical variables involved in the plasma transport phenomenon and the high complexity of its dynamics call for a model-based, multivariable approach to profile control where those predictive models could be exploited. The overall objective of this project has been to extend the existing body of work by investigating numerically and experimentally active control of unstable fluctuations, including fully developed turbulence and the associated cross-field particle transport, via manipulation of flow profiles in a magnetized laboratory plasma device. Fluctuations and particle transport can be monitored by an array of electrostatic probes, and Ex B flow profiles can be controlled via a set of biased concentric ring electrodes that terminate the plasma column. The goals of the proposed research have been threefold: i- to develop a predictive code to simulate plasma transport in the linear HELCAT (HELicon-CAThode) plasma device at the University of New Mexico (UNM), where the experimental component of the proposed research has been carried out; ii- to establish the feasibility of using advanced model-based control algorithms to control cross-field turbulence-driven particle transport through appropriate manipulation of radial plasma flow profiles, iii- to investigate the fundamental nonlinear dynamics of turbulence and transport physics. Lehigh University (LU), including Prof. Eugenio Schuster and one full-time graduate student, has been primarily responsible for control-oriented modeling and model-based control design. Undergraduate students have also participated in this project through the National Science Foundation Research Experience for Undergraduate (REU) program. The main goal of the LU Plasma Control Group has been to study the feasibility of controlling turbulence-driven transport by shaping the radial poloidal flow profile (i.e., by controlling flow shear) via biased concentric ring electrodes.

  2. Experimental consideration of capillary chromatography based on tube radial distribution of ternary mixture carrier solvents under laminar flow conditions.

    PubMed

    Jinno, Naoya; Hashimoto, Masahiko; Tsukagoshi, Kazuhiko

    2011-01-01

    A capillary chromatography system has been developed based on the tube radial distribution of the carrier solvents using an open capillary tube and a water-acetonitrile-ethyl acetate mixture carrier solution. This tube radial distribution chromatography (TRDC) system works under laminar flow conditions. In this study, a phase diagram for the ternary mixture carrier solvents of water, acetonitrile, and ethyl acetate was constructed. The phase diagram that included a boundary curve between homogeneous and heterogeneous solutions was considered together with the component ratios of the solvents in the homogeneous carrier solutions required for the TRDC system. It was found that the TRDC system performed well with homogeneous solutions having component ratios of the solvents that were positioned near the homogeneous-heterogeneous solution boundary of the phase diagram. For preparing the carrier solutions of water-hydrophilic/hydrophobic organic solvents for the TRDC system, we used for the first time methanol, ethanol, 1,4-dioxane, and 1-propanol, instead of acetonitrile (hydrophilic organic solvent), as well as chloroform and 1-butanol, instead of ethyl acetate (hydrophobic organic solvent). The homogeneous ternary mixture carrier solutions were prepared near the homogeneous-heterogeneous solution boundary. Analyte mixtures of 2,6-naphthalenedisulfonic acid and 1-naphthol were separated with the TRDC system using these homogeneous ternary mixture carrier solutions. The pressure change in the capillary tube under laminar flow conditions might alter the carrier solution from homogeneous in the batch vessel to heterogeneous, thus affecting the tube radial distribution of the solvents in the capillary tube. PMID:21415507

  3. A radial flow microfluidic device for ultra-high-throughput affinity-based isolation of circulating tumor cells.

    PubMed

    Murlidhar, Vasudha; Zeinali, Mina; Grabauskiene, Svetlana; Ghannad-Rezaie, Mostafa; Wicha, Max S; Simeone, Diane M; Ramnath, Nithya; Reddy, Rishindra M; Nagrath, Sunitha

    2014-12-10

    Circulating tumor cells (CTCs) are believed to play an important role in metastasis, a process responsible for the majority of cancer-related deaths. But their rarity in the bloodstream makes microfluidic isolation complex and time-consuming. Additionally the low processing speeds can be a hindrance to obtaining higher yields of CTCs, limiting their potential use as biomarkers for early diagnosis. Here, a high throughput microfluidic technology, the OncoBean Chip, is reported. It employs radial flow that introduces a varying shear profile across the device, enabling efficient cell capture by affinity at high flow rates. The recovery from whole blood is validated with cancer cell lines H1650 and MCF7, achieving a mean efficiency >80% at a throughput of 10 mL h(-1) in contrast to a flow rate of 1 mL h(-1) standardly reported with other microfluidic devices. Cells are recovered with a viability rate of 93% at these high speeds, increasing the ability to use captured CTCs for downstream analysis. Broad clinical application is demonstrated using comparable flow rates from blood specimens obtained from breast, pancreatic, and lung cancer patients. Comparable CTC numbers are recovered in all the samples at the two flow rates, demonstrating the ability of the technology to perform at high throughputs. PMID:25074448

  4. Viscoelastic flow-focusing in microchannels: scaling properties of the particle radial distributions.

    PubMed

    Romeo, Giovanni; D'Avino, Gaetano; Greco, Francesco; Netti, Paolo A; Maffettone, Pier Luca

    2013-07-21

    Particles suspended in non-Newtonian liquids flowing in channels may migrate transversally to the main flow direction as a result of normal stress gradients. Viscoelasticity-induced migration has proven to be an efficient mechanism to promote 3D flow-focusing in cylindrical microchannels, avoiding the need for complex and expensive apparati. In this work, we demonstrate the existence of a single dimensionless number (Θ) that governs the migration dynamics of particles in viscoelastic liquids flowing in micropipes at low Deborah numbers (Deborah number is the ratio of fluid and flow characteristic times). The definition of Θ in terms of the relevant fluid, flow and geometrical quantities is obtained by generalizing the particle migration velocity expression given in previous asymptotic analytical theories through numerical simulations. An extensive experimental investigation quantitatively confirms the novel predictions: the experimental particle distributions along the channel axial direction collapse on a single curve when rescaled in terms of the proposed dimensionless number. The results reported in this work give a simple and general way to define the flow-focusing conditions promoted by viscoelastic effects. PMID:23670133

  5. Radial Hele-Shaw flow with suction: Fully nonlinear pattern formation

    NASA Astrophysics Data System (ADS)

    Chen, Ching-Yao; Huang, Yu-Sheng; Miranda, José A.

    2014-05-01

    We study the development of intricate, fully nonlinear immiscible interfacial patterns in the suction-driven radial Hele-Shaw problem. The complex-shaped, contracting fluid-fluid interface arises when an initially circular blob of more viscous fluid, surrounded by less viscous one, is drawn into an eccentric point sink. We present sophisticated numerical simulations, based on a diffuse interface model, that capture the most prominent interfacial features revealed by existing experimental studies of the problem. The response of the system to changes in the capillary number is investigated, accurately revealing the occurrence of finger competition phenomena, and correctly describing the velocity behavior of both inward- and outward-pointing fingers. For the large-capillary-number regime, a set of complex interfacial features (finger merging, shielding, and pinch-off) whose experimental realization is still not available, are predicted.

  6. Universality Results for Multi-layer Radial Hele-Shaw Flows

    NASA Astrophysics Data System (ADS)

    Daripa, Prabir; Gin, Craig; Daripa Research Team

    2014-03-01

    Saffman-Taylor instability is a well known viscosity driven instability of an interface separating two immiscible fluids. We study linear stability of this displacement process in multi-layer radial Hele-Shaw geometry involving an arbitrary number of immiscible fluid phases. Universal stability results have been obtained and applied to design displacement processes that are considerably less unstable than the pure Saffman-Taylor case. In particular, we derive universal formula which gives specific values of the viscosities of the fluid layers corresponding to smallest unstable band. Other similar universal results will also be presented. The talk is based on ongoing work. Supported by an NPRP Grant # 08-777-1-141 from the Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors.

  7. The investigation of flow instabilities on a rotating disk with curvature in the radial direction

    NASA Technical Reports Server (NTRS)

    Intemann, P. A.; Clarkson, M. H.

    1982-01-01

    The major objective is to explore any visible differences of the flow field with wall curvature of the test body, including possible interaction between Taylor-Gortler instabilities present along concave walls and the inflexional instabilities investigated here. An experimental study was conducted with emphasis placed on making visual observations and recording photographically the flow instabilities present under three different rotating bodies: a flat disk, a concave paraboloid, and a convex paraboloid. The data collected for the three test bodies lead to the conclusion that the wall curvature of the concave and convex paraboloids did not alter the observed flow field significantly from that observed on the flat disk.

  8. Simultaneous effects of radial magnetic field and wall properties on peristaltic flow of Carreau-Yasuda fluid in curved flow configuration

    NASA Astrophysics Data System (ADS)

    Hayat, T.; Tanveer, A.; Alsaadi, F.

    2015-12-01

    The objective of present article is to address the magnetohydrodynamic (MHD) peristaltic flow of Carreau-Yasuda fluid in a curved geometry. The channel boundaries satisfy wall slip and compliant properties. The fluid is electrically conducting through an applied magnetic field in the radial direction. Heat transfer is also studied. Governing equation comprised the viscous dissipation effects. The non-linear expressions are first obtained and then approximated using long wavelength and low Reynolds number considerations. The resulting systems are solved for the series solutions. The expressions of velocity, temperature, heat transfer coefficient and stream function are obtained and analyzed via graphical illustrations.

  9. Sizing pumps for slurries

    SciTech Connect

    Akhtar, S.Z.

    1996-11-01

    Slurry characteristics have a significant impact on centrifugal pump performance. For instance, as particle size increases or the percent solids concentration increases, pump head and efficiency decrease. Therefore, before a slurry pump is selected, it is important to define the slurry characteristics as accurately as possible. The effect of the slurry characteristics on the head and efficiency of the centrifugal pump will be emphasized (the effect on flowrate is less significant). The effect of slurry characteristics is more predominant in smaller pumps (with smaller diameter impellers) than in larger pumps. The data and relationship between the various slurry parameters have been developed from correlations and nomographs published by pump vendors from their field data and test results. The information helps to avoid specifying an undersized pump/motor assembly for slurry service.

  10. Influence of long-scale length radial electric field components on zonal flow-like structures in the TJ-II stellarator

    NASA Astrophysics Data System (ADS)

    Losada, U.; Alonso, A.; van Milligen, B. Ph; Hidalgo, C.; Liu, B.; Pedrosa, M. A.; Silva, C.; the TJ-II team

    2016-08-01

    The influence of long-scale length radial electric fields on zonal flows-like structures has been studied in the TJ-II stellarator. This relation has been investigated in the edge plasma using two electrical rake probes. The results presented here show an empirical correlation between the properties of long-range correlations (LRCs) with zonal flow-like structures and the magnitude of radial (neoclassical, NC) electric fields in TJ-II neutral beam heated plasmas. These experimental findings show that the enhancement of the NC radial electric field \\boldsymbol{E}{\\mathbf{r}} increases the magnitude of LRCs, considered as a proxy of zonal flows, while the radial correlation length of the plasma potential fluctuations was found to decrease by about 40%. A strong relation between the magnitude of electric field structures with long and short radial scales was found. The calculated \\boldsymbol{E}{\\mathbf{r}}× \\boldsymbol{B} shearing rate corresponding to the short scale length structures of the radial electric field may be sufficient to regulate turbulence.

  11. An experimental and computational investigation of flow in a radial inlet of an industrial pipeline centrifugal compressor

    SciTech Connect

    Flathers, M.B.; Bache, G.E.; Rainsberger, R.

    1996-04-01

    The flow field of a complex three-dimensional radial inlet for an industrial pipeline centrifugal compressor has been experimentally determined on a half-scale model. Based on the experimental results, inlet guide vanes have been designed to correct pressure and swirl angle distribution deficiencies. The unvaned and vaned inlets are analyzed with a commercially available fully three-dimensional viscous Navier-Stokes code. Since experimental results were available prior to the numerical study, the unvaned analysis is considered a postdiction while the vaned analysis is considered a prediction. The computational results of the unvaned inlet have been compared to the previously obtained experimental results. The experimental method utilized for the unvaned inlet is repeated for the vaned inlet and the data have been used to verify the computational results. The paper will discuss experimental, design, and computational procedures, grid generation, boundary conditions, and experimental versus computational methods. Agreement between experimental and computational results is very good, both in prediction and postdiction modes. The results of this investigation indicate that CFD offers a measurable advantage in design, schedule, and cost and can be applied to complex, three-dimensional radial inlets.

  12. Electron source of triode type with radial converging electron flow for irradiation of cylindrical targets

    SciTech Connect

    Engelko, V. I.; Kuznetsov, V. S.; Mueller, Georg

    2009-01-15

    Design of an electron source of triode type is described, which produces a radial converging electron beam employed for modification of the outer surface of fuel element claddings. Experimental investigations of the source showed that beam current magnitude, efficiency of beam focusing to the target, stability of source operation, and beam pulse duration become worse when the target diameter drops below certain values. A method for the calculation of the source operation was developed. Calculations showed that the reason of worse source operation is the initial angular spread of electrons when the target diameter is small. Because of the angular spread a part of electrons passes by the target and oscillates between the target and cathode. The space charge of the oscillating electrons lowers the emission current magnitude and leads to the formation of a virtual cathode in the grid-target gap despite the fact that the emission beam current is less than the limiting one. Formation of a virtual cathode is a reason for the unstable source operation and restriction of the beam pulse duration. Recommendations for the improvement of the source design are suggested.

  13. Distributed control of reactive power flow in a radial distribution circuit with high photovoltaic penetration

    SciTech Connect

    Chertkov, Michael; Turitsyn, Konstantin; Backhaus, Scott; Sule, Petr

    2009-01-01

    We show how distributed control of reactive power can serve to regulate voltage and minimize resistive losses in a distribution circuit that includes a significant level of photovoltaic (PV) generation. To demonstrate the technique, we consider a radial distribution circuit with a single branch consisting of sequentially-arranged residential-scale loads that consume both real and reactive power. In parallel, some loads also have PV generation capability. We postulate that the inverters associated with each PV system are also capable of limited reactive power generation or consumption, and we seek to find the optimal dispatch of each inverter's reactive power to both maintain the voltage within an acceptable range and minimize the resistive losses over the entire circuit. We assume the complex impedance of the distribution circuit links and the instantaneous load and PV generation at each load are known. We compare the results of the optimal dispatch with a suboptimal local scheme that does not require any communication. On our model distribution circuit, we illustrate the feasibility of high levels of PV penetration and a significant (20% or higher) reduction in losses.

  14. [Radial variation and time lag of sap flow of Populus gansuensis in Minqin Oasis, Northwest].

    PubMed

    Dang, Hong-Zhong; Yang, Wen-Bin; Li, Wei; Zhang, You-Yan; Li, Chang-Long

    2014-09-01

    Sap flow of tree trunk is very important to reflect the dynamics of physiological activities, as well as to estimate the water consumption of individual plant. In the present study, we used the thermal dissipation technique to monitor the sap flow velocity (J) at four depth loci (i. e. 2 cm, 3 cm, 5 cm, 8 cm) of three Populus gansuensis trees (30 year-old) in Minqin Oasis for two consecutive growing seasons. The results showed that there were significant differences among J values at four depth loci under tree trunk cambium. J value at the 3 cm depth locus (J3) of the tree trunk was the highest, and then in sequences, were 2 cm, 5 cm and 8 cm depth loci (J2, J5 and J8). J value (J3) on typical sunny days in June with the highest atmospheric potential evapotranspiration (ET0) was up to 28.53 g · cm(-2) · h(-1), which was 1.42, 2.74 and 4.4 times of J2, J5 and J8, respectively. In the process of diurnal variation of sap flow velocity, the peak value time of J at the four depth loci of the tree trunk was different, but the differences among them were within 20 min. Furthermore, the peak value time of sap flow velocity was very different to that of solar radiation (Rs) and air vapour pressure deficit (VPD). The time lag between J and Rs was from 55 to 88 min on typical sunny days during the main growing seasons (from June to August), and, positively related to the depth of the locus under tree trunk cambium, while the time lag between J and VPD reached 60-96 min, and was negatively related to the depth of the locus. The seasonal variation patterns of J were consistent with ET0. With the increase of tree physiological activities, there was a trend that the major water transportation layer extended to the interior sapwood. The most important meteorological factor was the solar radiation, which primarily drove sap flow at different depths of tree trunk. However, the secondary factor changed along with the depth, and VPD became increasingly important with increasing the

  15. Rotor cavity flow and heat transfer with inlet swirl and radial outflow of cooling air

    NASA Astrophysics Data System (ADS)

    Staub, F. W.

    1992-06-01

    To enhance the reliability of turbine disk life prediction, experimental verification is necessary for analytical tools which calculate the heat transfer and flow field coefficients in turbine-stator cavities. A full-scale model of the forward cavity of a typical aircraft gas turbine is utilized employing a high-molecular-weight gas (Refrigerant-12) at ambient temperature and pressure conditions to match the dimensionless parameters at engine conditions. A first-order comparison is given of the velocity distribution and disk heat transfer coefficients calculated by the measured values and a CFD code.

  16. Ultrasound Analysis Of Slurries

    DOEpatents

    Soong, Yee; Blackwell, Arthur G.

    2005-11-01

    An autoclave reactor allows for the ultrasonic analysis of slurry concentration and particle size distribution at elevated temperatures and pressures while maintaining the temperature- and pressure-sensitive ultrasonic transducers under ambient conditions. The reactor vessel is a hollow stainless steel cylinder containing the slurry which includes a stirrer and a N.sub.2 gas source for directing gas bubbles through the slurry. Input and output transducers are connected to opposed lateral portions of the hollow cylinder for respectively directing sound waves through the slurry and receiving these sound waves after transmission through the slurry, where changes in sound wave velocity and amplitude can be used to measure slurry parameters. Ultrasonic adapters connect the transducers to the reactor vessel in a sealed manner and isolate the transducers from the hostile conditions within the vessel without ultrasonic signal distortion or losses.

  17. Ultrasound Analysis of Slurries

    DOEpatents

    Soong, Yee and Blackwell, Arthur G.

    2005-11-01

    An autoclave reactor allows for the ultrasonic analysis of slurry concentration and particle size distribution at elevated temperatures and pressures while maintaining the temperature- and pressure-sensitive ultrasonic transducers under ambient conditions. The reactor vessel is a hollow stainless steel cylinder containing the slurry which includes a stirrer and a N, gas source for directing gas bubbles through the slurry. Input and output transducers are connected to opposed lateral portions of the hollow cylinder for respectively directing sound waves through the slurry and receiving these sound waves after transmission through the slurry, where changes in sound wave velocity and amplitude can be used to measure slurry parameters. Ultrasonic adapters connect the transducers to the reactor vessel in a sealed manner and isolate the transducers from the hostile conditions within the vessel without ultrasonic signal distortion or losses.

  18. Analysis of three-dimensional groundwater flow toward a radial collector well in a finite-extent unconfined aquifer

    NASA Astrophysics Data System (ADS)

    Huang, C.-S.; Chen, J.-J.; Yeh, H.-D.

    2015-08-01

    This study develops a three-dimensional mathematical model for describing transient hydraulic head distributions due to pumping at a radial collector well (RCW) in a rectangular confined or unconfined aquifer bounded by two parallel streams and no-flow boundaries. The governing equation with a point-sink term is employed. A first-order free surface equation delineating the water table decline induced by the well is considered. The head solution for the point sink is derived by applying the methods of double-integral transform and Laplace transform. The head solution for a RCW is obtained by integrating the point-sink solution along the laterals of the RCW and then dividing the integration result by the sum of lateral lengths. On the basis of Darcy's law and head distributions along the streams, the solution for the stream depletion rate (SDR) can also be developed. With the aid of the head and SDR solutions, the sensitivity analysis can then be performed to explore the response of the hydraulic head to the change in a specific parameter such as the horizontal and vertical hydraulic conductivities, streambed permeability, specific storage, specific yield, lateral length and well depth. Spatial head distributions subject to the anisotropy of aquifer hydraulic conductivities are analyzed. A quantitative criterion is provided to identify whether groundwater flow at a specific region is 3-D or 2-D without the vertical component. In addition, another criterion is also given to allow the neglect of vertical flow effect on SDR. Conventional 2-D flow models can be used to provide accurate head and SDR predictions if satisfying these two criteria.

  19. Approximate analysis of three-dimensional groundwater flow toward a radial collector well in a finite-extent unconfined aquifer

    NASA Astrophysics Data System (ADS)

    Huang, C.-S.; Chen, J.-J.; Yeh, H.-D.

    2016-01-01

    This study develops a three-dimensional (3-D) mathematical model for describing transient hydraulic head distributions due to pumping at a radial collector well (RCW) in a rectangular confined or unconfined aquifer bounded by two parallel streams and no-flow boundaries. The streams with low-permeability streambeds fully penetrate the aquifer. The governing equation with a point-sink term is employed. A first-order free surface equation delineating the water table decline induced by the well is considered. Robin boundary conditions are adopted to describe fluxes across the streambeds. The head solution for the point sink is derived by applying the methods of finite integral transform and Laplace transform. The head solution for a RCW is obtained by integrating the point-sink solution along the laterals of the RCW and then dividing the integration result by the sum of lateral lengths. On the basis of Darcy's law and head distributions along the streams, the solution for the stream depletion rate (SDR) can also be developed. With the aid of the head and SDR solutions, the sensitivity analysis can then be performed to explore the response of the hydraulic head to the change in a specific parameter such as the horizontal and vertical hydraulic conductivities, streambed permeability, specific storage, specific yield, lateral length, and well depth. Spatial head distributions subject to the anisotropy of aquifer hydraulic conductivities are analyzed. A quantitative criterion is provided to identify whether groundwater flow at a specific region is 3-D or 2-D without the vertical component. In addition, another criterion is also given to allow for the neglect of vertical flow effect on SDR. Conventional 2-D flow models can be used to provide accurate head and SDR predictions if satisfying these two criteria.

  20. Optimal design of high damping force engine mount featuring MR valve structure with both annular and radial flow paths

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Choi, S. B.; Lee, Y. S.; Han, M. S.

    2013-11-01

    This paper focuses on the optimal design of a compact and high damping force engine mount featuring magnetorheological fluid (MRF). In the mount, a MR valve structure with both annular and radial flows is employed to generate a high damping force. First, the configuration and working principle of the proposed MR mount is introduced. The MRF flows in the mount are then analyzed and the governing equations of the MR mount are derived based on the Bingham plastic behavior of the MRF. An optimal design of the MR mount is then performed to find the optimal structure of the MR valve to generate a maximum damping force with certain design constraints. In addition, the gap size of MRF ducts is empirically chosen considering the ‘lockup’ problem of the mount at high frequency. Performance of the optimized MR mount is then evaluated based on finite element analysis and discussions on performance results of the optimized MR mount are given. The effectiveness of the proposed MR engine mount is demonstrated via computer simulation by presenting damping force and power consumption.

  1. Analytical and experimental study of flow through an axial turbine stage with a nonuniform inlet radial temperature profile

    NASA Technical Reports Server (NTRS)

    Schwab, J. R.; Stabe, R. G.; Whitney, W. J.

    1983-01-01

    Results are presented for a typical nonuniform inlet radial temperature profile through an advanced single-stage axial turbine and compared with the results obtained for a uniform profile. Gas temperature rises of 40 K to 95 K are predicted at the hub and tip corners at the trailing edges of the pressure surfaces in both the stator and rotor due to convection of hot fluid from the mean by the secondary flow. The inlet temperature profile is shown to be mixed out at the rotor exit survey plane (2.3 axial chords downstream of the rotor trailing edge) in both the analysis and the experiment. The experimental rotor exit angle profile for the nonuniform inlet temperature profile indicates underturning at the tip caused by increased clearance. Severe underturning also occurs at the mean, both with and without the nonuniform inlet temperature profile. The inviscid rotational flow code used in the analysis fails to predict the underturning at the mean, which may be caused by viscous effects. Previously announced in STAR as N83-27958

  2. Analytical and Experimental Study of Flow Through an Axial Turbine Stage with a Nonuniform Inlet Radial Temperature Profile

    NASA Technical Reports Server (NTRS)

    Schwab, J. R.; Stabe, R. G.; Whitney, W. J.

    1983-01-01

    Results are presented for a typical nonuniform inlet radial temperature profile through an advanced single-stage axial turbine and compared with the results obtained for a uniform profile. Gas temperature rises of 40 K to 95 K are predicted at the hub and tip corners at the trailing edges of the pressure surfaces in both the stator and rotor due to convection of hot fluid from the mean by the secondary flow. The inlet temperature profile is shown to be mixed out at the rotor exit survey plane (2.3 axial chords downstream of the rotor trailing edge) in both the analysis and the experiment. The experimental rotor exit angle profile for the nonuniform inlet temperature profile indicates underturning at the tip caused by increased clearance. Severe underturning also occurs at the mean, both with and without the nonuniform inlet temperature profile. The inviscid rotational flow code used in the analysis fails to predict the underturning at the mean, which may be caused by viscous effects.

  3. Weak Radial Artery Pulse

    PubMed Central

    Venugopalan, Poothirikovil; Sivakumar, Puthuval; Ardley, Robert G.; Oates, Crispian

    2012-01-01

    We present an 11year-old boy with a weak right radial pulse, and describe the successful application of vascular ultrasound to identify the ulnar artery dominance and a thin right radial artery with below normal Doppler flow velocity that could explain the discrepancy. The implications of identifying this anomaly are discussed. PMID:22375269

  4. Possible evidence for radial flow of heavy mesons in d + Au collisions

    NASA Astrophysics Data System (ADS)

    Sickles, Anne M.

    2014-04-01

    Recent measurements of particle correlations and the spectra of hadrons at both RHIC and the LHC are suggestive of hydrodynamic behavior in very small collision systems (p + Pb, d + Au and possibly high multiplicity p + p collisions at the LHC). The measurements in p + Pb and d + Au collisions are both qualitatively and quantitatively similar to what is seen in heavy ion collisions where low viscosity hot nuclear matter is formed. While light quarks and gluons are thought to make up the bulk matter, one of the most surprising results in heavy ion collisions is that charm quarks also have a large v2. Measurements of the transverse momentum spectra of electrons from the decay of D and B mesons in d + Au collisions show an enhancement in central collisions relative to p + p collisions. We employ the blast-wave model to determine if the flow of heavy quarks in d + Au and p + Pb collisions is able to explain the enhancement observed in the data. We find a reasonable description of the data with blast-wave parameters extracted from fits to the light hadron spectra, suggesting hydrodynamics as a possible explanation.

  5. Redundant vasodilator pathways underlying radial artery flow-mediated dilation are preserved in healthy aging.

    PubMed

    Ballard, Kevin D; Tschakovsky, Michael E; Zaleski, Amanda L; Polk, Donna M; Thompson, Paul D; Kiernan, Francis J; Parker, Beth A

    2014-01-01

    Background. Blocking nitric oxide (NO) and vasodilator prostanoids (PN) does not consistently reduce flow-mediated dilation (FMD) in young adults. The impact of aging on the contribution of NO and PG to FMD is unknown. Methods. FMD was measured in older adults (n = 10, 65 ± 3 y) after arterial infusion of saline, N(G)-monomethyl-L-arginine (L-NMMA), and ketorolac + L-NMMA. Data were compared to published data in young adults. Results. L-NMMA reduced FMD in older adults (8.9 ± 3.6 to 5.9 ± 3.7%) although this was not statistically significant (P = 0.08) and did not differ (P = 0.74) from the reduction observed in young adults (10.0 ± 3.8 to 7.6 ± 4.7%; P = 0.03). Blocking PN did not affect FMD in young or older adults. In older adults, L-NMMA reduced (n = 6; range = 36-123% decrease), augmented (n = 3; 10-122% increase), or did not change FMD (n = 1; 0.4% increase). After PN blockade, FMD responses were reduced (n = 2), augmented (n = 6), or unaffected (n = 1). Conclusions. NO or PN blockade did not consistently reduce FMD in healthy older adults, suggesting the existence of redundant vasodilator phenotypes as observed previously in young adults. PMID:24963406

  6. Redundant Vasodilator Pathways Underlying Radial Artery Flow-Mediated Dilation Are Preserved in Healthy Aging

    PubMed Central

    Ballard, Kevin D.; Tschakovsky, Michael E.; Zaleski, Amanda L.; Polk, Donna M.; Thompson, Paul D.; Kiernan, Francis J.; Parker, Beth A.

    2014-01-01

    Background. Blocking nitric oxide (NO) and vasodilator prostanoids (PN) does not consistently reduce flow-mediated dilation (FMD) in young adults. The impact of aging on the contribution of NO and PG to FMD is unknown. Methods. FMD was measured in older adults (n = 10, 65 ± 3 y) after arterial infusion of saline, N(G)-monomethyl-L-arginine (L-NMMA), and ketorolac + L-NMMA. Data were compared to published data in young adults. Results. L-NMMA reduced FMD in older adults (8.9 ± 3.6 to 5.9 ± 3.7%) although this was not statistically significant (P = 0.08) and did not differ (P = 0.74) from the reduction observed in young adults (10.0 ± 3.8 to 7.6 ± 4.7%; P = 0.03). Blocking PN did not affect FMD in young or older adults. In older adults, L-NMMA reduced (n = 6; range = 36–123% decrease), augmented (n = 3; 10–122% increase), or did not change FMD (n = 1; 0.4% increase). After PN blockade, FMD responses were reduced (n = 2), augmented (n = 6), or unaffected (n = 1). Conclusions. NO or PN blockade did not consistently reduce FMD in healthy older adults, suggesting the existence of redundant vasodilator phenotypes as observed previously in young adults. PMID:24963406

  7. Radial diffusion and penetration of gas molecules and aerosol particles through laminar flow reactors, denuders, and sampling tubes.

    PubMed

    Knopf, Daniel A; Pöschl, Ulrich; Shiraiwa, Manabu

    2015-04-01

    Flow reactors, denuders, and sampling tubes are essential tools for many applications in analytical and physical chemistry and engineering. We derive a new method for determining radial diffusion effects and the penetration or transmission of gas molecules and aerosol particles through cylindrical tubes under laminar flow conditions using explicit analytical equations. In contrast to the traditional Brown method [Brown, R. L. J. Res. Natl. Bur. Stand. (U. S.) 1978, 83, 1-8] and CKD method (Cooney, D. O.; Kim, S. S.; Davis, E. J. Chem. Eng. Sci. 1974, 29, 1731-1738), the new approximation developed in this study (known as the KPS method) does not require interpolation or numerical techniques. The KPS method agrees well with the CKD method under all experimental conditions and also with the Brown method at low Sherwood numbers. At high Sherwood numbers corresponding to high uptake on the wall, flow entry effects become relevant and are considered in the KPS and CKD methods but not in the Brown method. The practical applicability of the KPS method is demonstrated by analysis of measurement data from experimental studies of rapid OH, intermediate NO3, and slow O3 uptake on various organic substrates. The KPS method also allows determination of the penetration of aerosol particles through a tube, using a single equation to cover both the limiting cases of high and low deposition described by Gormley and Kennedy (Proc. R. Ir. Acad., Sect. A. 1949, 52A, 163-169). We demonstrate that the treatment of gas and particle diffusion converges in the KPS method, thus facilitating prediction of diffusional loss and penetration of gases and particles, analysis of chemical kinetics data, and design of fluid reactors, denuders, and sampling lines. PMID:25744622

  8. Methods to enhance the characteristics of hydrothermally prepared slurry fuels

    SciTech Connect

    Anderson, C.M.; Musich, M.A.; Mann, M.D.; DeWall, R.A.; Richter, J.J.; Potas, T.A.; Willson, W.G.

    2000-04-25

    Methods are disclosed for enhancing the flow behavior and stability of hydrothermally treated slurry fuels. A mechanical high-shear dispersion and homogenization device is used to shear the slurry fuel. Other improvements include blending the carbonaceous material with a form of coal to reduce or eliminate the flocculation of the slurry, and maintaining the temperature of the hydrothermal treatment between approximately 300 to 350 C.

  9. Methods to enhance the characteristics of hydrothermally prepared slurry fuels

    DOEpatents

    Anderson, Chris M.; Musich, Mark A.; Mann, Michael D.; DeWall, Raymond A.; Richter, John J.; Potas, Todd A.; Willson, Warrack G.

    2000-01-01

    Methods for enhancing the flow behavior and stability of hydrothermally treated slurry fuels. A mechanical high-shear dispersion and homogenization device is used to shear the slurry fuel. Other improvements include blending the carbonaceous material with a form of coal to reduce or eliminate the flocculation of the slurry, and maintaining the temperature of the hydrothermal treatment between approximately 300.degree. to 350.degree. C.

  10. CHARACTERIZING PULSATING MIXING OF SLURRIES

    SciTech Connect

    Bamberger, Judith A.; Meyer, Perry A.

    2007-12-01

    This paper describes the physical properties for defining the operation of a pulse jet mixing system. Pulse jet mixing operates with no moving parts located in the vessel to be mixed. Pulse tubes submerged in the vessel provide a pulsating flow due to a controlled combination of applied pressure to expel the fluid from the pulse tube nozzle followed by suction to refill the pulse tube through the same nozzle. For mixing slurries nondimensional parameters to define mixing operation include slurry properties, geometric properties and operational parameters. Primary parameters include jet Reynolds number and Froude number; alternate parameters may include particle Galileo number, particle Reynolds number, settling velocity ratio, and hindered settling velocity ratio. Rating metrics for system performance include just suspended velocity, concentration distribution as a function of elevation, and blend time.

  11. Mn2O3 Slurry Achieving Reduction of Slurry Waste

    NASA Astrophysics Data System (ADS)

    Kishii, Sadahiro; Nakamura, Ko; Hanawa, Kenzo; Watanabe, Satoru; Arimoto, Yoshihiro; Kurokawa, Syuhei; Doi, Toshiro K.

    2012-04-01

    Fumed silica is widely used for SiO2 chemical mechanical polishing (CMP). In semiconductor processes, only fresh slurry is used, the used slurry being disposed of. We have demonstrated that Mn2O3 abrasive slurry polishes dielectric SiO2 film, giving 4 times the removal rate of conventional fumed silica slurry. The higher removal rate reduces the total amount of slurry used, consequently reducing the amount of used slurry waste. The removal rate of Mn2O3 slurry remains constant for solid concentrations between l and 10 wt %, and stays constant without pad conditioning. These characteristics are very useful for slurry reuse. Remanufacture of Mn2O3 slurry from used slurry has been demonstrated, and the removal rates of the remanufactured and fresh slurries are the same. Reuse and remanufacturing drastically reduce the amount of waste.

  12. ICE SLURRY APPLICATIONS

    PubMed Central

    Kauffeld, M.; WANG, M. J.; Goldstein, V.; Kasza, K. E.

    2011-01-01

    The role of secondary refrigerants is expected to grow as the focus on the reduction of greenhouse gas emissions increases. The effectiveness of secondary refrigerants can be improved when phase changing media are introduced in place of single phase media. Operating at temperatures below the freezing point of water, ice slurry facilitates several efficiency improvements such as reductions in pumping energy consumption as well as lowering the required temperature difference in heat exchangers due to the beneficial thermo-physical properties of ice slurry. Research has shown that ice slurry can be engineered to have ideal ice particle characteristics so that it can be easily stored in tanks without agglomeration and then be extractable for pumping at very high ice fraction without plugging. In addition ice slurry can be used in many direct contact food and medical protective cooling applications. This paper provides an overview of the latest developments in ice slurry technology. PMID:21528014

  13. ICE SLURRY APPLICATIONS.

    PubMed

    Kauffeld, M; Wang, M J; Goldstein, V; Kasza, K E

    2010-12-01

    The role of secondary refrigerants is expected to grow as the focus on the reduction of greenhouse gas emissions increases. The effectiveness of secondary refrigerants can be improved when phase changing media are introduced in place of single phase media. Operating at temperatures below the freezing point of water, ice slurry facilitates several efficiency improvements such as reductions in pumping energy consumption as well as lowering the required temperature difference in heat exchangers due to the beneficial thermo-physical properties of ice slurry. Research has shown that ice slurry can be engineered to have ideal ice particle characteristics so that it can be easily stored in tanks without agglomeration and then be extractable for pumping at very high ice fraction without plugging. In addition ice slurry can be used in many direct contact food and medical protective cooling applications. This paper provides an overview of the latest developments in ice slurry technology. PMID:21528014

  14. Receptor-mediated cell attachment and detachment kinetics. II. Experimental model studies with the radial-flow detachment assay.

    PubMed Central

    Cozens-Roberts, C; Quinn, J A; Lauffenburger, D A

    1990-01-01

    Quantitative information regarding the kinetics of receptor-mediated cell adhesion to a ligand-coated surface are crucial for understanding the role of certain key parameters in many physiological and biotechnology-related processes. Here, we use the probabilistic attachment and detachment models developed in the preceding paper to interpret transient data from well-defined experiments. These data are obtained with a simple model cell system that consists of receptor-coated latex beads (prototype cells) and a Radial-Flow Detachment Assay (RFDA) using a ligand-coated glass disc. The receptors and ligands used in this work are complementary antibodies. The beads enable us to examine transient behavior with particles that possess fairly uniform properties that can be varied systematically, and the RFDA is designed for direct observation of adhesion to the ligand-coated glass surface over a range of shear stresses. Our experiments focus on the effects of surface shear stress, receptor density, and ligand density. These data provide a crucial test of the probabilistic framework. We show that these data can be explained with the probabilistic analyses, whereas they cannot be readily interpreted on the basis of a deterministic analysis. In addition, we examine transient data on cell adhesion reported from other assays, demonstrating the consistency of these data with the predictions of the probabilistic models. Images FIGURE 2 PMID:2174272

  15. The influence of additives on rheological properties of limestone slurry

    NASA Astrophysics Data System (ADS)

    Jaworska, B.; Bartosik, A.

    2014-08-01

    Limestone slurry appears in the lime production process as the result of rinsing the processed material. It consists of particles with diameter smaller than 2 mm and the water that is a carrier of solid fraction. Slurry is directed to the settling tank, where the solid phase sediments and the excess water through the transfer system is recovered for re-circulation. Collected at the bottom of the tank sludge is deposited in a landfill located on the premises. Rheological properties of limestone slurry hinder its further free transport in the pipeline due to generated flow resistance. To improve this state of affairs, chemical treatment of drilling fluid, could be applied, of which the main task is to give the slurry properties suitable for the conditions encountered in hydrotransport. This treatment consists of applying chemical additives to slurry in sufficient quantity. Such additives are called as deflocculants or thinners or dispersants, and are chemical compounds which added to aqueous solution are intended to push away suspended particles from each other. The paper presents the results of research allowing reduction of shear stress in limestone slurry. Results demonstrate rheological properties of limestone slurry with and without the addition of modified substances which causes decrease of slurry viscosity, and as a consequence slurry shear stress for adopted shear rate. Achieving the desired effects increases the degree of dispersion of the solid phase suspended in the carrier liquid and improving its ability to smooth flow with decreased friction.

  16. Spatial analysis of aquifer response times for radial flow processes: Nondimensional analysis and laboratory-scale tests

    NASA Astrophysics Data System (ADS)

    Jazaei, Farhad; Simpson, Matthew J.; Clement, T. Prabhakar

    2016-01-01

    A fundamental concept in groundwater hydrology is the notion of steady state, or equilibrium conditions. When a system at some initial steady state condition is perturbed by pumping, a transient cone of depression will develop and the system will approach a new steady state condition. Understanding the time scale required for the transient process to occur is of practical interest since it would help practitioners decide whether to use a steady state model or a more complicated transient model. Standard approaches to estimate the response time use simple scaling relationships which neglect spatial variations. Alternatively, others define the response time to be the amount of time taken for the difference between the transient and steady state solutions to fall below some arbitrary tolerance level. Here, we present a novel approach and use the concept of mean action time to predict aquifer response time scales in a two-dimensional radial geometry for pumping, injection and recovery processes. Our approach leads to relatively simple closed form expressions that explicitly show how the time scale depends on the hydraulic parameters and position. Furthermore, our dimensionless framework allows us to predict the response time scales for a range of applications including small scale laboratory problems and large scale field problems. Our analysis shows that the response time scales vary spatially, but are equivalent for pumping, injection and associated recovery processes. Furthermore, the time scale is independent of the pumping or injection flow rate. We test these predictions in a laboratory scale aquifer and find that our physical measurements corroborate the theoretical predictions.

  17. Slurry pumping techniques for feeding high-pressure coal gasification reactors

    NASA Technical Reports Server (NTRS)

    Bair, W. G.; Tarman, P. B.

    1977-01-01

    Operating experience in pumping coal and coal char slurries at pressures up to 1500 psig is discussed. The design specifications for the mixing tanks, pumps, piping, and slurry heaters are given along with pressure drop and minimum flow velocity data on water-lignite slurries.

  18. Pressurized Vessel Slurry Pumping

    SciTech Connect

    Pound, C.R.

    2001-09-17

    This report summarizes testing of an alternate ''pressurized vessel slurry pumping'' apparatus. The principle is similar to rural domestic water systems and ''acid eggs'' used in chemical laboratories in that material is extruded by displacement with compressed air.

  19. Impact of higher alginate expression on deposition of Pseudomonas aeruginosa in radial stagnation point flow and reverse osmosis systems.

    PubMed

    Herzberg, Moshe; Rezene, Tesfalem Zere; Ziemba, Christopher; Gillor, Osnat; Mathee, Kalai

    2009-10-01

    Extracellular polymeric substances (EPS) have major impact on biofouling of reverse osmosis (RO) membranes. On one hand, EPS can reduce membrane permeability and on the other, EPS production by the primary colonizers may influence their deposition and attachment rate and subsequently affect the biofouling propensity of the membrane. The role of bacterial exopolysaccharides in bacterial deposition followed by the biofouling potential of an RO membrane was evaluated using an alginate overproducing (mucoid) Pseudomonas aeruginosa. The mucoid P. aeruginosa PAOmucA22 was compared with its isogenic nonmucoid prototypic parent PAO1 microscopically in a radial stagnation point flow (RSPF) system for their bacterial deposition characteristics. Then, biofouling potential of PAO1 and PAOmucA22 was determined in a crossflow rectangular plate-and-frame membrane cell, in which the strains were cultivated on a thin-film composite, polyamide, flat RO membrane coupon (LFC-1) under laminar flow conditions. In the RSPF system, the observed deposition rate of the mucoid strain was between 5- and 10-fold lower than of the wild type using either synthetic wastewater medium (with ionic strength of 14.7 mM and pH 7.4) or 15 mM KCl solution (pH of 6.2). The slower deposition rate of the mucoid strain is explained by 5- to 25-fold increased hydrophilicity of the mucoid strain as compared to the isogenic wild type, PAO1. Corroborating with these results, a significant delay in the onset of biofouling of the RO membrane was observed when the mucoid strain was used as the membrane colonizer, in which the observed time for the induced permeate flux decline was delayed (ca. 2-fold). In conclusion, the lower initial cell attachment of the mucoid strain decelerated biofouling of the RO membrane. Bacterial deposition and attachment is a critical step in biofilm formation and governed by intimate interactions between outer membrane proteins of the bacteria and the surface. Shielding these

  20. Bubble column apparatus for separating wax from catalyst slurry

    SciTech Connect

    Neathery, James K.; Davis, Burtron H.

    2004-07-13

    Novel methods and devices for production of liquid hydrocarbon products from gaseous reactants are disclosed. In one aspect, a method for separating a liquid hydrocarbon, typically a wax, from a catalyst containing slurry is provided, comprising passing the slurry through at least one downcomer extending from an overhead separation chamber and discharging into the bottom of a slurry bubble column reactor. The downcomer includes a cross-flow filtration element for separating a substantially particle-free liquid hydrocarbon for downstream processing. In another aspect, a method for promoting plug-flow movement in a recirculating slurry bubble column reactor is provided, comprising discharging the recirculating slurry into the reactor through at least one downcomer which terminates near the bottom of the reactor. Devices for accomplishing the above methods are also provided.

  1. System for pressure letdown of abrasive slurries

    DOEpatents

    Kasper, Stanley

    1991-01-01

    A system and method for releasing erosive slurries from containment at high pressure without subjecting valves to highly erosive slurry flow. The system includes a pressure letdown tank disposed below the high-pressure tank, the two tanks being connected by a valved line communicating the gas phases and a line having a valve and choke for a transfer of liquid into the letdown tank. The letdown tank has a valved gas vent and a valved outlet line for release of liquid. In operation, the gas transfer line is opened to equalize pressure between tanks so that a low level of liquid flow occurs. The letdown tank is then vented, creating a high-pressure differential between the tanks. At this point, flow between tanks is controlled by the choke. High-velocity, erosive flow through a high-pressure outlet valve is prevented by equalizing the start up pressure and thereafter limiting flow with the choke.

  2. System for pressure letdown of abrasive slurries

    SciTech Connect

    Kasper, S.

    1991-10-01

    This patent describes a system and method for releasing erosive slurries from containment at high pressure without subjecting valves to highly erosive slurry flow. The system includes a pressure letdown tank disposed below the high-pressure tank, the two tanks being connected by a valved line communicating the gas phases and a line having a valve and choke for a transfer of liquid into the letdown tank. The letdown tank has a valved gas vent and a valved outlet line for release of liquid. In operation, the gas transfer line is opened to equalize pressure between tanks so that a low level of liquid flow occurs. The letdown tank is then vented, creating a high-pressure differential between the tanks. At this point, flow between tanks is controlled by the choke. High-velocity, erosive flow through a high-pressure outlet valve is prevented by equalizing the start up pressure and thereafter limiting flow with the choke.

  3. Reducing NO(x) emissions from a nitric acid plant of domestic petrochemical complex: enhanced conversion in conventional radial-flow reactor of selective catalytic reduction process.

    PubMed

    Abbasfard, Hamed; Hashemi, Seyed Hamid; Rahimpour, Mohammad Reza; Jokar, Seyyed Mohammad; Ghader, Sattar

    2013-01-01

    The nitric acid plant of a domestic petrochemical complex is designed to annually produce 56,400 metric tons (based on 100% nitric acid). In the present work, radial-flow spherical bed reactor (RFSBR) for selective catalytic reduction of nitric oxides (NO(x)) from the stack of this plant was modelled and compared with the conventional radial-flow reactor (CRFR). Moreover, the proficiency of a radial-flow (water or nitrogen) membrane reactor was also compared with the CRFR which was found to be inefficient at identical process conditions. In the RFSBR, the space between the two concentric spheres is filled by a catalyst. A mathematical model, including conservation of mass has been developed to investigate the performance of the configurations. The model was checked against the CRFR in a nitric acid plant located at the domestic petrochemical complex. A good agreement was observed between the modelling results and the plant data. The effects of some important parameters such as pressure and temperature on NO(x) conversion were analysed. Results show 14% decrease in NO(x) emission annually in RFSBR compared with the CRFR, which is beneficial for the prevention of NO(x) emission, global warming and acid rain. PMID:24527652

  4. The solution-adaptive numerical simulation of the 3D viscous flow in the serpentine coolant passage of a radial inflow turbine blade

    NASA Astrophysics Data System (ADS)

    Dawes, W. N.

    1992-06-01

    This paper describes the application of a solution-adaptive, three-dimensional Navier-Stokes solver to the problem of the flow in turbine internal coolant passages. First the variation of Nusselt number in a cylindrical, multi-ribbed duct is predicted and found to be in acceptable agreement with experimental data. Then the flow is computed in the serpentine coolant passage of a radial inflow turbine including modeling the internal baffles and pin fins. The aerodynamics of the passage, particularly that associated with the pin fins, is found to be complex. The predicted heat transfer coefficients allow zones of poor coolant penetration and potential hot spots to be identified.

  5. Rocketdyne's advanced coal slurry pumping program

    NASA Technical Reports Server (NTRS)

    Davis, D. E.; Wong, G. S.; Gilman, H. H.

    1977-01-01

    The Rocketdyne Division of Rockwell International Corporation is conducting a program for the engineering, fabrication, and testing of an experimental/prototype high-capacity, high-pressure centrifugal slurry feed pump for coal liquefaction purposes. The abrasion problems in a centrifugal slurry pump are primarily due to the manner in which the hard, solid particles contained in the slurry are transported through the hydraulic flow passages within the pump. The abrasive particles can create scraping, grinding, cutting, and sandblasting effects on the various exposed parts of the pump. These critical areas involving abrasion and impact erosion wear problems in a centrifugal pump are being addressed by Rocketdyne. The mechanisms of abrasion and erosion are being studied through hydrodynamic analysis, materials evaluation, and advanced design concepts.

  6. Differences in the Properties of the Radial Artery between Cun, Guan, Chi, and Nearby Segments Using Ultrasonographic Imaging: A Pilot Study on Arterial Depth, Diameter, and Blood Flow

    PubMed Central

    Kim, Jaeuk U.; Lee, Yu Jung; Kim, Jong Yeol

    2015-01-01

    Aim of the Study. The three conventional pulse-diagnostic palpation locations (PLs) on both wrists are Cun, Guan, and Chi, and each location reveals different clinical information. To identify anatomical or hemodynamic specificity, we used ultrasonographic imaging to determine the arterial diameter, radial artery depth, and arterial blood flow velocity at the three PLs and at nearby non-PL segments. Methods. We applied an ultrasound scanner to 44 subjects and studied the changes in the arterial diameter and depth as well as in the average/maximum blood flow velocities along the radial artery at three PLs and three non-PLs located more proximally than Chi. Results. All of the measurements at all of the PLs were significantly different (P < 0.01). Artery depth was significantly different among the non-PLs; however, this difference became insignificant after normalization to the arm circumference. Conclusions. Substantial changes in the hemodynamic and anatomical properties of the radial artery around the three PLs were insignificant at the nearby non-PLs segments. This finding may provide a partial explanation for the diagnostic use of “Cun, Guan, and Chi.” PMID:25763090

  7. Pipelining particulate solid material as stable foam slurry

    SciTech Connect

    Fitch, J.L.

    1980-04-29

    A method of transporting particulate solid material through a pipeline in the form of a stable foam slurry is described. A pumpable slurry is formed of the particulate solid material in a stable foam carrier medium and the slurry is flowed through the pipeline to a receiving point. A method of transporting particulate solid materials through a pipeline is described wherein a pumpable slurry is formed of the particulate solid material. The particulate material is present in the stable foam in an amount of at least 20% by volume based on the total volume of the stable foam slurry. The particulate solid material may be coal particles, other forms of particulate carbonaceous material, such as coke, lignite and pitch, ores, and still other particulate material which is insoluble in the stable foam. The foam may be formed from a liquid, usually water, gas, and a foam stabilizing agent, such as a soap or a surfactant. 4 claims.

  8. Fuel injection of coal slurry using vortex nozzles and valves

    DOEpatents

    Holmes, Allen B.

    1989-01-01

    Injection of atomized coal slurry fuel into an engine combustion chamber is achieved at relatively low pressures by means of a vortex swirl nozzle. The outlet opening of the vortex nozzle is considerably larger than conventional nozzle outlets, thereby eliminating major sources of failure due to clogging by contaminants in the fuel. Control fluid, such as air, may be used to impart vorticity to the slurry and/or purge the nozzle of contaminants during the times between measured slurry charges. The measured slurry charges may be produced by a diaphragm pump or by vortex valves controlled by a separate control fluid. Fluidic circuitry, employing vortex valves to alternatively block and pass cool slurry fuel flow, is disclosed.

  9. Flashing Slurry Releases

    SciTech Connect

    Schmitt, Bruce E.; Young, Jonathan

    2007-03-14

    The Hanford K Basin Closure Project involves the retrieval, transfer and processing of radioactive contaminated slurries containing partially corroded spent nuclear fuel from the K Basin spent fuel pools. The spent fuel is primarily metallic fuel from the operation of the Hanford reactors. The Sludge Treatment Project is being designed to treat and package this material in preparation for ultimate disposal. The processing of the contaminated slurries includes further corrosion of the remaining uncorroded uranium metal in a large heated vessel to form a more stable metal oxide for packaging and storage.

  10. New slurry pumps in China

    SciTech Connect

    Li, Z.; Wang, W.; Shi, Z.

    1998-07-01

    Wet parts of centrifugal slurry pumps are naturally subjected to wear, but local wear in pumps could be avoided, at least partly. Through studying the wear phenomenon of slurry pumps in industrial applications, a series of much more advanced slurry pumps was developed in China. Laboratory tests and industrial applications show that the new pumps are high in efficiency when transporting slurries, and uniform wear can be expected from them.

  11. New slurry pumps in China

    SciTech Connect

    Zhengwang Li; Wenlie Wang; Zhongyin Shi

    1998-04-01

    Wet parts of centrifugal slurry pumps are naturally subjected to wear, but local wear in pumps could be avoided, at least partly. Through studying the wear phenomenon of slurry pumps in industrial applications, a series of much more advanced slurry pumps was developed in China. Laboratory tests and industrial applications show that the new pumps are high in efficiency when transporting slurries, and uniform wear can be expected from them.

  12. Defluoridation of wastewaters using waste carbon slurry.

    PubMed

    Gupta, Vinod Kumar; Ali, Imran; Saini, Vipin Kumar

    2007-08-01

    Adsorption of fluoride on waste carbon slurry was investigated. Waste carbon slurry was obtained from fuel oil based generators of a fertilizer industry. The work involves batch experiments to investigate the effects of contact time, pH, temperature and adsorbent dose on the extent of adsorption by carbon slurry. The contact time and pH for maximum fluoride uptake were found 1h and 7.58, respectively. Maximum adsorption capacity (4.861 mg g(-1)) of fluoride on carbon slurry was observed at 15.00 mg L(-1) initial fluoride concentration using 1.0 g L(-1) adsorbent dose. Among four applied models, the experimental isotherm data were found to follow Langmuir equation more closely. Thermodynamically, adsorption was found endothermic with values 7.348 kJ mol(-1), -25.410 kJ mol(-1) and 0.109 kJ mol(-1)K(-1) for enthalpy, free energy and entropy, respectively showing the feasibility of adsorption process. From kinetic analysis, the adsorption was found to follow second-order mechanism with rate constant 49.637 gm g(-1)min(-1). The rate-controlling step of the adsorption was found pore diffusion controlled. In order to investigate the potential of this adsorbent on industrial scale, column and desorption experiments were carried out. The breakthrough capacity of column was calculated 4.155 mg g(-1) with at a flow rate of 1.5 mL min(-1). The proposed adsorbent has been used to remove fluoride from groundwater and wastewater. Desorption has been achieved under alkaline conditions (pH 11.6) from exhausted carbon slurry. The performance of carbon slurry was compared with many other reported adsorbent for fluoride removal and it was observed that proposed adsorbent is effective in terms of performance and cost especially. PMID:17583767

  13. Slurry reactor design studies

    SciTech Connect

    Fox, J.M.; Degen, B.D.; Cady, G.; Deslate, F.D.; Summers, R.L. ); Akgerman, A. ); Smith, J.M. )

    1990-06-01

    The objective of these studies was to perform a realistic evaluation of the relative costs of tublar-fixed-bed and slurry reactors for methanol, mixed alcohols and Fischer-Tropsch syntheses under conditions where they would realistically be expected to operate. The slurry Fischer-Tropsch reactor was, therefore, operated at low H{sub 2}/CO ratio on gas directly from a Shell gasifier. The fixed-bed reactor was operated on 2.0 H{sub 2}/CO ratio gas after adjustment by shift and CO{sub 2} removal. Every attempt was made to give each reactor the benefit of its optimum design condition and correlations were developed to extend the models beyond the range of the experimental pilot plant data. For the methanol design, comparisons were made for a recycle plant with high methanol yield, this being the standard design condition. It is recognized that this is not necessarily the optimum application for the slurry reactor, which is being proposed for a once-through operation, coproducing methanol and power. Consideration is also given to the applicability of the slurry reactor to mixed alcohols, based on conditions provided by Lurgi for an Octamix{trademark} plant using their standard tubular-fixed reactor technology. 7 figs., 26 tabs.

  14. Emplacement-related layering in magma slurries

    NASA Astrophysics Data System (ADS)

    Petford, N.

    2009-04-01

    Textures and structures such as layering, grading and foliations preserved in igneous rocks offer a glimpse into the magma emplacement process. However, despite recent advances, a full and proper understanding of the fluid dynamics of congested fluid-particle mixtures during shear remains elusive. This is a shame as without recourse to such fundamental understanding, the interpretation of structural field data in the context of magma flow remains problematic. One way to gain insight into the process is to treat flowing magma as a dynamic material with a rheology similar to sheared, congested slurries. The idea that dense magma equates to a high temperature slurry is an attractive one, and opens up a way to examine the emplacement process that does not rely on equilibrium thermodynamics as a final explanation for commonly observed igneous structures. Using the Basement Sill, Antarctica, as a world class example of a magmatic slurry, shearing at high Peclet (Pe) number where particle diffusion is negligible has the potential to impart a rich diversity of structures including layering, grading and flow segregation. Work to model numerically the flow of the Basement Sill slurry using a range of theoretical and experimentally-derived non-Newtonian magma rheologies will be presented and assessed. A key impilcation is that in addition to more classical explanations such as compaction and gravitational settling, igneous layering can also arise spontaneously during shear associated with the ascent and emplacement of congested magma. A final aspect of the emplacement model considers the irregular geometry of the Basement Sill boundaries. Movement of magma along these boundaries results in the formation of local eddies and fluid swirl/back-flow that add additional complexity to macroscopic flow field.

  15. Critical parameters for coarse coal underground slurry haulage systems

    SciTech Connect

    Maynard, D.P.

    1981-02-15

    This report describes the basic parameters which directly influence the behavior of a coal slurry pipeline transportation system and determine the limitations of the system performance. The purpose of this technology assessment is to provide an identification and understanding of the critical factors which must be given consideration in the design and evaluation of such a slurry haulage system intended for use in an underground coal mine. The slurry haulage system will be utilized to satisfy the transportation requirements of conveying, in a pipeline, the coal mined by a continuous mining machine to a storage location near the mine entrance or to a coal preparation plant located on the surface. Coal-water slurries, particularly those consisting of homogeneous suspensions of small particles, frequently behave as non-Newtonian, Bingham-plastic fluids. For successful operation, slurry transport systems should be designed to operate in the turbulent flow regime and at a flow rate at least 30% greater than the deposition velocity. The deposition velocity is defined as the slurry flow rate at which the solid particles tend to settle in the pipe. Due to the importance of accurately determining the deposition velocity and the uncertainties of current methods for predicting the deposition velocity of coarse particle slurries, it is recommended that experimental efforts be performed as a part of the system design. The capacity of the haulage system should be compatible with the mine's projected coal output in order to avoid operational delays and the necessity for in-mine coal storage. The slurry pumps must generate sufficient discharge pressure to overcome the resultant friction losses in horizontal and vertical pipe sections and to satisfy the slurry hoisting requirements.

  16. High pressure slurry pump. Sand slurry test loop design and results. Wear parts lifetime analysis

    SciTech Connect

    Fongaro, S.; Severini, P.; Vinciguerra, G.

    2000-07-01

    This paper shows the experimental phase, following previous work presented at the Sixth International Conference on ``Multiphase Flow in Industrial Plants'', Milan, September 98. A Sand Water Slurry Test Loop has been tested using different sand percentages for a total power of 680 HP with a flow-rate of 35,000 [gpm] and pressure of 2300 [psig]. Its design considered, carefully, the particles build-up effect respecting flow velocity and dead space along the loop and into the hydraulics. The test pump is a TRIPLEX SINGLE ACTING that is one third of the COAL SLURRY SEPTUPLEX PUMP designed for a CHINA PROJECT. Wear rate on the main parts of an high pressure slurry pump have been analyzed running at 145 rpm (piston mean speed of 3.3 [ft/s]) with a net flow of 33,290 [gpm] and pressures between 1216 and 1575 [psig]. Tests gave indications of a damaging process on valves, piston seals and the relative weight on the overall damages. Design changes of piston-seal and its material have been done, results being a longer parts lifetime. The authors compared the results with literature on coal slurry and other sand tests. The pump speed, i.e., valve cycle, isn't the main wear factor, while the fluid speed under the valve is. Their goals are to improve the wear parts lifetime and define functions to relate the wear to operating parameters, design choice, and materials used.

  17. Influence of heat and mass transfer, initial stress and radially varying magnetic field on the peristaltic flow in an annulus with gravity field

    NASA Astrophysics Data System (ADS)

    Abd-Alla, A. M.; Abo-Dahab, S. M.; El-Shahrany, H. D.

    2014-08-01

    In this paper, the effects of both initial stress, radially varying and gravity field on the peristaltic flow of an incompressible MHD Newtonian fluid in a vertical annulus have been studied under the assumption of long wavelength and low-Reynolds number. The analytical solution has been derived for the temperature, concentration and velocity. The results for velocity, concentration and temperature obtained in the analytical form have been evaluated numerically and discussed briefly. The effect of the non-dimensional wave amplitude, the coefficient of viscosity, Sort number, Schmidt number, initial stress, gravitational field and the dimensionless time-mean flow in the wave frame are analyzed theoretically and computed numerically. The expressions for pressure rise, temperature, concentration field, velocity and pressure gradient are sketched for various embedded parameters and interpreted. Numerical results are given and illustrated graphically in each case considered. Comparison was made with the results obtained in the presence and absence of initial stress and gravitational field.

  18. The coal slime slurry combustion technology

    SciTech Connect

    Li, Y.; Xu, Z.

    1997-12-31

    This paper presents the coal slime slurry combustion technology in circulating fluidized bed (CFB) boilers. The technique is that the slurry-based flow from the concentrator in the coal washery plant directly feeds into the fluidized bed by pump for combustion after a simple filtration and enrichment to an approximate concentration of 50% of coal. The coal slime slurry can burn in a CFB boiler alone or jointly with coal refuse. The technique has been used in a 35 t/h (6MWe) CFB for power generation. The result shows that the combustion efficiency is over 96% and boiler thermal efficiency is over 77%. As compared with burning coal refuse alone, the thermal efficiency was improved by 3--4 percent. This technology is simple, easy to operate and reliable. It is an effective way to utilize coal slime slurry. It has a practical significance for saving coal resources and reducing environmental pollution near coal mine areas. As a clean coal technology, it will result in great social, environmental and economic benefits.

  19. Application of a quasi-3D inviscid flow and boundary layer analysis to the hub-shroud contouring of a radial turbine

    NASA Technical Reports Server (NTRS)

    Civinskas, K. C.; Povinelli, L. A.

    1984-01-01

    Application of a quasi-3D approach to the aerodynamic analysis of several radial turbine configurations is described. The objective was to improve the rotor aerodynamic characteristics by hub-shroud contouring. The approach relies on available 2D inviscid methods coupled with boundary layer analysis to calculate profile, mixing, and endwall losses. Windage, tip clearance, incidence, and secondary flow losses are estimated from correlations. To eliminate separation along the hub and blade suction surfaces of a baseline rotor, the analysis was also applied to three alternate hub-shroud geometries. Emphasis was on elimination an inducer velocity overshoot as well as increasing hub velocities. While separation was never eliminated, the extent of the separated area was progressively reduced. Results are presented in terms of mid-channel and blade surface velocities; kinetic energy loss coefficients; and efficiency. The calculation demonstrates a first step for a systematic approach to radial turbine design that can be used to identify and control aerodynamic characteristics that ultimately determine heat transfer and component life. Experimentation will be required to assess the extent to which flow and boundary layer behavior were predicted correctly.

  20. Slurry atomizer for a coal-feeder and dryer used to provide coal at gasifier pressure

    DOEpatents

    Loth, John L.; Smith, William C.; Friggens, Gary R.

    1982-01-01

    The present invention is directed to a coal-water slurry atomizer for use a high-pressure dryer employed in a pumping system utilized to feed coal into a pressurized coal gasifier. The slurry atomizer is provided with a venturi, constant area slurry injection conduit, and a plurality of tangentially disposed steam injection ports. Superheated steam is injected into the atomizer through these ports to provide a vortical flow of the steam, which, in turn, shears slurry emerging from the slurry injection conduit. The droplets of slurry are rapidly dispersed in the dryer through the venturi where the water is vaporized from the slurry by the steam prior to deleterious heating of the coal.

  1. System and method for slurry handling

    SciTech Connect

    Steele, Raymond Douglas; Oppenheim, Judith Pauline

    2015-12-29

    A system includes a slurry depressurizing system that includes a liquid expansion system configured to continuously receive a slurry at a first pressure and continuously discharge the slurry at a second pressure. For example, the slurry depressurizing system may include an expansion turbine to expand the slurry from the first pressure to the second pressure.

  2. Slurry burner for mixture of carbonaceous material and water

    DOEpatents

    Nodd, Dennis G.; Walker, Richard J.

    1987-01-01

    A carbonaceous material-water slurry burner includes a high pressure tip-emulsion atomizer for directing a carbonaceous material-water slurry into a combustion chamber for burning therein without requiring a support fuel or oxygen enrichment of the combustion air. Introduction of the carbonaceous material-water slurry under pressure forces it through a fixed atomizer wherein the slurry is reduced to small droplets by mixing with an atomizing air flow and directed into the combustion chamber. The atomizer includes a swirler located immediately adjacent to where the fuel slurry is introduced into the combustion chamber and which has a single center channel through which the carbonaceous material-water slurry flows into a plurality of diverging channels continuous with the center channel from which the slurry exits the swirler immediately adjacent to an aperture in the combustion chamber. The swirler includes a plurality of slots around its periphery extending the length thereof through which the atomizing air flows and by means of which the atomizing air is deflected so as to exert a maximum shear force upon the carbonaceous material-water slurry as it exits the swirler and enters the combustion chamber. A circulating coolant system or boiler feed water is provided around the periphery of the burner along the length thereof to regulate burner operating temperature, eliminate atomizer plugging, and inhibit the generation of sparklers, thus increasing combustion efficiency. A secondary air source directs heated air into the combustion chamber to promote recirculation of the hot combustion gases within the combustion chamber.

  3. Transient radial flow to a well in an unconfined aquifer. Part 1, An evaluation of some conceptual methods

    SciTech Connect

    Narasimhan, T.N.; Zhu, Ming

    1991-08-01

    The analytic solutions of Boulton (1954) and Neuman (1972) for transient flow to a well in an unconfined aquifer are based on the assumption that the role of the unsaturated zone can be adequately accounted for by restricting attention to the release of water from the zone through which the water table moves. Both researchers mathematically treat this released water as a time-dependent source term. The differences between the models of Boulton and Neuman are that the former neglects vertical components of flow in the aquifer, but allows for an exponential process for the release of water as a function of time, whereas the latter assumes instantaneous release from storage, but accounts for vertical components of flow. Given this set of assumptions, we examine the applicability of these two methods using a general purpose numerical model through a process of verification extension and comparison. The issues addressed include: the role of well-bore storage in masking intermediate-time behavior, combined effects of exponential release as well as vertical flow, logic for vertical averaging of drawdowns, and the sensitivity of system response to the magnitude of specific yield. The issue of how good the assumptions of Boulton and Neuman are in the context of the general theory of unsaturated flow is addressed in part 2 of this two-part series of reports.

  4. Improvement in Accuracy of Ultrasonic Measurement of Transient Change in Viscoelasticity of Radial Arterial Wall Due to Flow-Mediated Dilation by Adaptive Low-Pass Filtering

    NASA Astrophysics Data System (ADS)

    Ikeshita, Kazuki; Hasegawa, Hideyuki; Kanai, Hiroshi

    2012-07-01

    In our previous study, the stress-strain relationship of the radial arterial wall was measured and the viscoelasticity of the intima-media region was estimated from the stress-strain relationship. Furthermore, the transient change in viscoelasticity due to flow-mediated dilation (FMD) was estimated by the automated detection of wall boundaries. In the present study, the strain rate was adaptively filtered to improve the accuracy of viscoelasticity estimation by decreasing the high-frequency noise. Additionally, in a basic experiment, this method was validated using a silicone tube (simulating artery). In the basic experiment, the elasticity was estimated with a mean error of 1.2%. The elasticity measured at each beam position was highly reproducible among measurements, whereas there was a slight variation in measured elasticity among beams. Consequently, in in vivo measurements, the normalized mean square error (MSE) was clearly decreased. Additionally, the stress-strain relationship of the radial arterial wall was obtained and the viscoelasticity was estimated accurately. The inner small loop, which corresponds to the negative pressure wave caused by the closure of the aortic valve, can be observed using the adaptive low-pass filtering (LPF). Moreover, the transient changes in these parameters were similar to those in the previous study. These results show the potential of the proposed method for the thorough analysis of the transient change in viscoelasticity due to FMD.

  5. MHD flow and heat transfer of a viscous fluid over a radially stretching power-law sheet with suction/injection in a porous medium

    NASA Astrophysics Data System (ADS)

    Khan, M.; Munir, A.; Shahzad, A.; Shah, A.

    2015-03-01

    A steady boundary layer flow and heat transfer over a radially stretching isothermal porous sheet is analyzed. Stretching is assumed to follow a radial power law, and the fluid is electrically conducting in the presence of a transverse magnetic field with a very small magnetic Reynolds number. The governing nonlinear partial differential equations are reduced to a system of nonlinear ordinary differential equations by using appropriate similarity transformations, which are solved analytically by the homotopy analysis method (HAM) and numerically by employing the shooting method with the adaptive Runge-Kutta method and Broyden's method in the domain [0,∞). Analytical expressions for the velocity and temperature fields are derived. The influence of pertinent parameters on the velocity and temperature profiles is discussed in detail. The skin friction coefficient and the local Nusselt number are calculated as functions of several influential parameters. The results predicted by both methods are demonstrated to be in excellent agreement. Moreover, HAM results for a particular problem are also compared with exact solutions.

  6. Suspended-slurry reactor

    DOEpatents

    None

    2016-03-22

    An apparatus for generating a large volume of gas from a liquid stream is disclosed. The apparatus includes a first channel through which the liquid stream passes. The apparatus also includes a layer of catalyst particles suspended in a solid slurry for generating gas from the liquid stream. The apparatus further includes a second channel through which a mixture of converted liquid and generated gas passes. A heat exchange channel heats the liquid stream. A wicking structure located in the second channel separates the gas generated from the converted liquid.

  7. Batch gravitational sedimentation of slurries.

    PubMed

    Chu, C P; Ju, S P; Lee, D J; Mohanty, K K

    2002-01-01

    We investigated the batch settling behavior of the kaolin slurry and the UK ball clay slurry at various initial solids fractions (phi(0)s) using a computerized axial tomography scanner (CATSCAN). The spatio-temporal evolutions of solids fractions in the consolidating sediments were continuously monitored. Since the interface between the sediment and the supernatant of the investigated slurries was blurred, an averaging procedure was employed to estimate their null-stress solids fractions (phi(g)s). Besides the rather slow settling for the high-phi(0) slurries, the basic settling characteristics resemble each other regardless of whether phi(0)>phi(g) or vice versa. The above-mentioned experimental data reveal that the investigated slurries are neither purely elastic nor purely plastic in rheological behavior. On contrary to most model works a blurred supernatant-sediment interface makes difficulty in the gel point determination. During initial settling the high-phi(0) slurries clearly exhibit a finite yield stress to resist deformation. That is, the slurries are plastic fluids. However, the network structure in the slurries deteriorates gradually in the subsequent settling stage while the final, equilibrated sediment reveals a continuous distribution in solids fraction. Restated, the final sediment possesses as a purely elastic characteristic. The model parameters of theory by Buscall and White were regressed by the dynamic consolidating sediment data, while those by Tiller and Leu were obtained using the final equilibrated sediment data. Calculations from both models reveal that ball clay slurry is more compressible than is the kaolin slurry. The high-phi(S0) slurry would yield the less compressible sediment. PMID:16290348

  8. Radial lean direct injection burner

    DOEpatents

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  9. Waste slurry particle properties for use in slurry flow modeling

    SciTech Connect

    JEWETT, J.R.

    2003-01-01

    The Department of Energy's River Protection Project is building a Waste Treatment Plant to convert the nuclear waste stored in the Hanford Site's underground storage tank system into final waste forms

  10. ANALYTICAL APPROXIMATION OF THE BIODEGRADATION RATE FOR IN SITU BIOREMEDIATION OF GROUNDWATER UNDER IDEAL RADIAL FLOW CONDITIONS. (R824785)

    EPA Science Inventory

    We derive the long-term biodegradation rate of an organic contaminant (substrate) for an in situ bioremediation model with axisymmetric flow conditions. The model presumes that a nonsorbing electron acceptor is injected into a saturated homogeneous porous medium which initially c...

  11. Coal slurry transportation alternatives: Conceptual design and economics: Final report

    SciTech Connect

    Mann, C.E.; Manning, S.H.

    1987-07-01

    The Coal Slurry Transportation Alternatives study provides utilities with a decisionmaking tool and necessary cost data to facilitate a systematic and rigorous comparison of slurry, rail, and barge transportation from the mine to the busbar for coal deliveries to both existing and new power plants. Volume 3 summarizes the methodology and results of examining operating and cost differences between slurry and run-of-mine coal. Two objectives of the study are to document the engineering costs and assumptions of the coal slurry pipeline system and to provide comparative estimates of costs and performance for power generation from slurry pipeline and run-of-mine coal. The results indicate that an increase in fuel moisture causes a decrease in boiler efficiency; that is, higher fuel burn rates and higher gas flows. For new plants, major equipment must be sized to accommodate higher fuel, ash, and flue gas flow rates associated with coal slurry. Other impacts include higher auxiliary power requirements, increased scrubber additive requirements, and potential increases in plant maintenance. For existing plants, a more serious concern may be the capability of current fuel transport systems to properly dry and transport the fuel. Flue gas flow rates for slurry should be within the design margins of run-of-mine, but where flue gas flow rates are increased, downstream FGD and particulate removal equipment may be impacted. Of the total levelized busbar costs for new plants, approximately 40 percent of differential costs are associated with capital, with the remaining 60 percent associated with consumables. For existing plants, replacement power costs due to limitations in fuel drying and conveyance may be up to 20 percent of the total generation cost. 40 figs., 62 tabs.

  12. The effects of the secondary fluid temperature on the energy transfer in an unsteady ejector with a radial-flow diffuser

    NASA Astrophysics Data System (ADS)

    Ababneh, Amer Khalil; Jawarneh, Ali M.; Tlilan, Hitham M.; Ababneh, Mohammad K.

    2009-11-01

    Unsteady ejectors are devices whereby energy is exchanged between directly interacting fluids. Unlike steady ejectors, the mechanism responsible for the energy transfer is reversible in nature and thus higher efficiencies are perceivable. A potential application for PEE is for enhancement in output power per weight as in turbochargers. The unsteady ejector when used as a turbocharger the device is expected to perform under wide range of ambient temperatures. Therefore, it is important to investigate the effects of the temperature of the induced ambient air on the energy transfer. The radial-flow ejector, which usually leads to higher-pressure ratios with fewer stages, was selected for the investigation. The flow field is investigated at two Mach numbers 2.5 and 3.0 utilizing rectangular short-length supersonic nozzles for accelerating the primary fluid. Fundamental to the enhancement of these devices performance relies on the management of the flow field in such a way to minimize entropy production. The numerical analyses were conducted utilizing a package of computational fluid dynamics.

  13. Fischer-Tropsch Slurry Reactor modeling

    SciTech Connect

    Soong, Y.; Gamwo, I.K.; Harke, F.W.

    1995-12-31

    This paper reports experimental and theoretical results on hydrodynamic studies. The experiments were conducted in a hot-pressurized Slurry-Bubble Column Reactor (SBCR). It includes experimental results of Drakeol-10 oil/nitrogen/glass beads hydrodynamic study and the development of an ultrasonic technique for measuring solids concentration. A model to describe the flow behavior in reactors was developed. The hydrodynamic properties in a 10.16 cm diameter bubble column with a perforated-plate gas distributor were studied at pressures ranging from 0.1 to 1.36 MPa, and at temperatures from 20 to 200{degrees}C, using a dual hot-wire probe with nitrogen, glass beads, and Drakeol-10 oil as the gas, solid, and liquid phase, respectively. It was found that the addition of 20 oil wt% glass beads in the system has a slight effect on the average gas holdup and bubble size. A well-posed three-dimensional model for bed dynamics was developed from an ill-posed model. The new model has computed solid holdup distributions consistent with experimental observations with no artificial {open_quotes}fountain{close_quotes} as predicted by the earlier model. The model can be applied to a variety of multiphase flows of practical interest. An ultrasonic technique is being developed to measure solids concentration in a three-phase slurry reactor. Preliminary measurements have been made on slurries consisting of molten paraffin wax, glass beads, and nitrogen bubbles at 180 {degrees}C and 0.1 MPa. The data show that both the sound speed and attenuation are well-defined functions of both the solid and gas concentrations in the slurries. The results suggest possibilities to directly measure solids concentration during the operation of an autoclave reactor containing molten wax.

  14. INEZ, KENTUCKY COAL SLURRY SPILL

    EPA Science Inventory

    On October 11th, 2000, a breach of a coal slurry impoundment released approximately 210 million gallons of coal slurry ( a mixture of fine coal particles, silt, clay, sand and water) into the Big Andy Branch, Wolf Creek, and Coldwater Fork. Approximately 75 river miles were affec...

  15. Travel time distributions under convergent radial flow in heterogeneous formations: Insight from the analytical solution of a stratified model

    NASA Astrophysics Data System (ADS)

    Pedretti, Daniele; Fiori, Aldo

    2013-10-01

    We analyze conservative solute transport under convergent flow to a well in perfectly stratified porous media, in which the hydraulic conductivity is treated as a random spatial function along the vertical direction (K(z)). The stratified model provides a rare exception of an exact analytical solution of travel time distributions in the proximity of pumping wells, and it is used here to obtain insights about ergodic and nonergodic transport conditions under nonuniform flow conditions. In addition, it provides a benchmark for numerical models aiming to correctly reproduce convergent flow transport in heterogeneous media, such as indicating the minimum number of layers required to obtain ergodic travel time distributions using only one model realization. The model provides important insights about the shape of the depth-integrated concentrations over time measured at the well (breakthrough curves, BTCs), which are usually applied to obtain transport parameters of the subsurface. It can be applied to any degree of system's heterogeneity and using either resident or flux-weighted injection modes. It can be built using different probabilistic distributions of K. In our analysis, we consider a log-normal K distribution, and the results indicate that, especially for highly heterogeneous systems, described by the log-K variance (σY2), the minimum number of layers required for from one model simulation to reproduce ergodic travel time distributions can be prohibitively high, e.g., above 106 for σY2=8 considering flux-weighted injections. This issue poses serious concerns for numerical applications aiming to simulate transport in the proximity of pumping wells. In addition, this simple solution confirms that stratification can lead BTCs to display strong preferential flow and persistent, power-law-like late-time tailing. Since the latter are common phenomenological macroscale evidences of other microscale hydrodynamic processes than pure advection (e.g., mass

  16. DEHYDRATION OF DEUTERIUM OXIDE SLURRIES

    DOEpatents

    Hiskey, C.F.

    1959-03-10

    A method is presented for recovering heavy water from uranium oxide-- heavy water slurries. The method consists in saturating such slurries with a potassium nitrate-sodium nitrate salt mixture and then allowing the self-heat of the slurry to raise its temperature to a point slightly in excess of 100 deg C, thus effecting complete evaporation of the free heavy water from the slurry. The temperature of the slurry is then allowed to reach 300 to 900 deg C causing fusion of the salt mixture and expulsion of the water of hydration. The uranium may be recovered from the fused salt mixture by treatment with water to leach the soluble salts away from the uranium-containing residue.

  17. Rheometry of natural sediment slurries

    USGS Publications Warehouse

    Major, Jon J.

    1993-01-01

    Recent experimental analyses of natural sediment slurries yield diverse results yet exhibit broad commonality of rheological responses under a range of conditions and shear rates. Results show that the relation between shear stress and shear rate is primarily nonlinear, that the relation can display marked hysteresis, that minimum shear stress can occur following yield, that physical properties of slurries are extremely sensitive to sediment concentration, and the concept of slurry yield strength is still debated. New rheometric analyses have probed viscoelastic behavior of sediment slurries. Results show that slurries composed of particles ??? 125 ?? m exhibit viscoelastic responses, and that shear stresses are relaxed over a range of time scales rather than by a single response time.

  18. Roles of additives and surface control in slurry atomization

    SciTech Connect

    Tsai, S.C.

    1992-01-01

    This project studies the rheology and airblast atomization of micronized coal slurries. Its major objectives are (1) to promote further understanding of the mechanisms and the roles of additives in airblast atomization of coal water slurry (CWS), and (2) to investigate the impacts of coal particle surface properties and interparticle forces on CWS rheology. We have found that the flow behavior index (n) of a suspension (or slurry) is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The interparticle attraction, measured by the Hamaker constant scaled to the thermal energy at 25[degrees]C (A/kT), causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior (n< 1). At a constant particle volume fraction and surface charge density (qualitatively measured by the zeta potential in deionized water), n decreases linearly as A/kT increases. The relative viscosity of the pseudoplastic suspension with respect to that of the suspending liquid is found to be independent of particle density and correlate well with the particle Peclet number which equals the particle diffusional relaxation time multiplied by shear rate. Specifically, the relative viscosities of the pseudoplastic glycerol/water coal slurry and the ethylene glycol/glycerol sand slurry, at same volume fractions as well as similar particle size distributions and liquid viscosities, as functions of the particle Peclet number fall along the same line.

  19. Radial Erosion

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    The ejecta surrounding the crater (off image to the left) in this image has undergone significant erosion by the wind. The wind has stripped the surface features from the ejecta and has started to winnow away the ejecta blanket. Near the margin of the ejecta the wind is eroding along a radial pattern -- taking advantage of radial emplacement. Note the steep margin of the ejecta blanket. Most, if not all, of the fine ejecta material has been removed and the wind in now working on the more massive continuous ejecta blanket.

    Image information: VIS instrument. Latitude 12.5, Longitude 197.4 East (162.6 West). 37 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. Radial and circumferential flow surveys at the inlet and exit of the Space Shuttle Main Engine High Pressure Fuel Turbine Model

    NASA Astrophysics Data System (ADS)

    Hudson, S. T.; Bordelon, W. J., Jr.; Smith, A. W.; Ramachandran, N.

    1995-01-01

    The main objective of this test was to obtain detailed radial and circumferential flow surveys at the inlet and exit of the SSME High Pressure Fuel Turbine model using three-hole cobra probes, hot-film probes, and a laser velocimeter. The test was designed to meet several objectives. First, the techniques for making laser velocimeter, hot-film probe, and cobra probe measurements in turbine flows were developed and demonstrated. The ability to use the cobra probes to obtain static pressure and, therefore, velocity had to be verified; insertion techniques had to be established for the fragile hot-film probes; and a seeding method had to be established for the laser velocimetry. Once the measurement techniques were established, turbine inlet and exit velocity profiles, temperature profiles, pressure profiles, turbulence intensities, and boundary layer thicknesses were measured at the turbine design point. The blockage effect due to the model inlet and exit total pressure and total temperature rakes on the turbine performance was also studied. A small range of off-design points were run to obtain the profiles and to verify the rake blockage effects off-design. Finally, a range of different Reynolds numbers were run to study the effect of Reynolds number on the various measurements.

  1. Numerical investigation of a coupled moving boundary model of radial flow in low-permeable stress-sensitive reservoir with threshold pressure gradient

    NASA Astrophysics Data System (ADS)

    Wen-Chao, Liu; Yue-Wu, Liu; Cong-Cong, Niu; Guo-Feng, Han; Yi-Zhao, Wan

    2016-02-01

    The threshold pressure gradient and formation stress-sensitive effect as the two prominent physical phenomena in the development of a low-permeable reservoir are both considered here for building a new coupled moving boundary model of radial flow in porous medium. Moreover, the wellbore storage and skin effect are both incorporated into the inner boundary conditions in the model. It is known that the new coupled moving boundary model has strong nonlinearity. A coordinate transformation based fully implicit finite difference method is adopted to obtain its numerical solutions. The involved coordinate transformation can equivalently transform the dynamic flow region for the moving boundary model into a fixed region as a unit circle, which is very convenient for the model computation by the finite difference method on fixed spatial grids. By comparing the numerical solution obtained from other different numerical method in the existing literature, its validity can be verified. Eventually, the effects of permeability modulus, threshold pressure gradient, wellbore storage coefficient, and skin factor on the transient wellbore pressure, the derivative, and the formation pressure distribution are analyzed respectively. Project supported by the National Natural Science Foundation of China (Grant No. 51404232), the China Postdoctoral Science Foundation (Grant No. 2014M561074), and the National Science and Technology Major Project, China (Grant No. 2011ZX05038003).

  2. Oscillatory limited compressible fluid flow induced by the radial motion of a thick-walled piezoelectric tube

    NASA Astrophysics Data System (ADS)

    Shin, Dong-Youn; Grassia, Paul; Derby, Brian

    2003-09-01

    A simple oscillatory, slightly compressible, fluid flow model in a thick-walled piezoelectric tube used in a drop-on-demand inkjet print head is developed from the point of view of fluid-structure interaction to take account of pressure wave propagation and pressure loading opposing wall motion. A frequency sweep is performed computationally using the model revealing the first acoustic fluid-structure resonance frequency and the influence of fluid viscosity. The validity of the model, with given information on the speed of sound in a fluid, is evaluated by comparing the theoretically predicted resonance frequency to the experimentally measured resonance frequency. In addition, the intrinsic speed of sound can be easily computed using the measured acoustic resonance frequency and this computed speed of sound agrees closely with speeds of sound reported in the literature.

  3. Effects of climatic conditions on radial growth and sap-flow along an elevation gradient in an inner-alpine dry valley

    NASA Astrophysics Data System (ADS)

    Obojes, Nikolaus; Newesely, Christian; Bertoldi, Giacomo; Tassser, Erich; Oberhuber, Walter; Mayr, Stefan; Tappeiner, Ulrike

    2016-04-01

    Water availability in mountain forests might change in the future due to rising temperatures and changing precipitation patterns, affecting tree water relations and growth conditions. Changing temperature and precipitation along an elevation gradient in an inner-alpine dry valley in South Tyrol-Italy were used to investigate possible effects of climate change on the transpiration and growth of European Larch (Larix decidua). Stem circumference variation of European Larch was measured for 4 years (2012-2015) with automatic band dendrometers and sap flow for 2 years (2013-2014) with trunk heat balance sensors at 3 sites at elevations of 1115 m, 1715 m, and 1990 m above sea level at a SE-exposed slope. During the first two, rather dry, years, transpiration and stem circumference were reduced during dry periods of one to three weeks at the two lower but not at the highest site. As a consequence, overall yearly radial growth was largest at the highest site in those two years. In 2014, with very high precipitation and colder summer temperatures no correlation of elevation, transpiration, and radial growth was observed. In 2015, with a dry and hot summer, initially high growth rates were strongly reduced after the end of May at the two lower sites. Overall the radial growth of Larix decidua seems to be limited by water scarcity up to an elevation of more than 1700 m a.s.l. in our study area except for unusually wet years. Our 4-year measurements were confirmed by dendro-climatic analysis of stem cores taken at five sites (the three original ones plus two additional sites at 1070 and at the forest line at 2250m) covering the last 50 to 150 years. Year ring widths were lower and highly correlated to precipitation at the lowest sites, and overall highest at the 1990 m site. Our results show that the growth of Larix decidua, which is often considered as more drought resistant than e.g. Picea abies, is limited by water availability at dry conditions in the Alps which might

  4. MERIDL- VELOCITIES AND STREAMLINES ON THE HUB-SHROUD MIDCHANNEL STREAM SURFACE OF AN AXIAL, RADIAL, OR MIXED FLOW TURBOMACHINE OR ANNULAR DUCT

    NASA Technical Reports Server (NTRS)

    Katsanis, T.

    1994-01-01

    general the blade row may be fixed or rotating and the blades may be twisted and leaned. The flow may be axial, radial, or mixed. The upstream and downstream flow conditions can vary from hub to shroud with provisions made for an approximate correction for loss of stagnation pressure. Also, viscous forces are neglected along solution mesh lines running from hub to tip. The capabilities of this program include handling of nonaxial flows without restriction, annular ducts without blades, and specified streamwise loss distributions. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 360 computer with a central memory requirement of approximately 700K of 8 bit bytes. This core requirement can be reduced depending on the size of the problem and the desired solution accuracy. This program was developed in 1977.

  5. Rheology of coal slurries. Final report

    SciTech Connect

    Ulbrecht, J.J.; Ryan, M.E.

    1982-01-01

    Experimental investigations of suspensions of three size distributions of glass spheres in a solution of tetralin and tetrabromoethane were made using a Haake viscometer. The values of viscosity were determined over a range of shear rates from 1 to 1000 sec/sup -1/. The suspending medium is Newtonian with a viscosity of about 9.66 centipoise at 25 +- 1/sup 0/C. At phi less than or equal to 20%, the suspension exhibited Newtonian behavior but at phi greater than or equal to 30%, the suspension exhibited pronounced non-Newtonian behavior. Experimental studies of these three size distributions were also conducted in aqueous solutions of polyvinylpyrrolidone using a pipe loop apparatus. Viscosity was measured over the shear rate range from 600 to 6000 sec./sup -1/. These suspensions having non-Newtonian suspending media, exhibit non-Newtonian behavior at all concentration levels of the solid particles. In the limit of very high shear rates, the suspension viscosity was found to be independent of tube diameter over the range of shear rates and concentrations studied. The rheological behavior of slurries of irregularly-shaped anthracite coal particles was also systematically investigated. The suspending medium consisted of a mixture of anthracene oil and tetrabromoethane. The shear rate was varied from 0.01 to 1000 sec./sup -1/. Volume concentrations range from 0 to 34%. At volume concentrations greater than 29% the slurries exhibited a yield stress and pronounced thixotropic behavior. The relative viscosities of both the model and the coal slurries were found to be dependent on both the shear rate and the particle size. In the case of the coal slurries caution must be exercised with regard to the proper interpretation of the rheological data due to the influences of the measured apparent density of the coal particles, viscometric flow geometry, and time dependent effects.

  6. Aqueous slurries of carbonaceous materials

    SciTech Connect

    Schick, M.J.; Knitter, K.A.

    1984-03-13

    Aqueous carbonaceous slurries having reduced viscosity, a stabilized network of carbonaceous material in water and improved pumpability are obtained by having present a salt of naphthalenesulfonic acid formaldehyde condensate and at least one water soluble polymer selected from the group consisting of sodium alginate, guar gum, locust bean gum, carboxymethylhydroxypropyl guar gum, hydroxypropyl guar gum and guarpak guar gum. For example, a mixture of 96.8% by weight of ammonium naphthalenesulfonic acid formaldehyde condensate and 3.2% by weight of sodium alginate can be added to an aqueous coal slurry in an amount of 0.31% by weight of the slurry.

  7. NACA Research on Slurry Fuels

    NASA Technical Reports Server (NTRS)

    Pinns, M L; Olson, W T; Barnett, H C; Breitwieser, R

    1958-01-01

    An extensive program was conducted to investigate the use of concentrated slurries of boron and magnesium in liquid hydrocarbon as fuels for afterburners and ramjet engines. Analytical calculations indicated that magnesium fuel would give greater thrust and that boron fuel would give greater range than are obtainable from jet hydrocarbon fuel alone. It was hoped that the use of these solid elements in slurry form would permit the improvement to be obtained without requiring unconventional fuel systems or combustors. Small ramjet vehicles fueled with magnesium slurry were flown successfully, but the test flights indicated that further improvement of combustors and fuel systems was needed.

  8. Manifold Coal-Slurry Transport System

    NASA Technical Reports Server (NTRS)

    Liddle, S. G.; Estus, J. M.; Lavin, M. L.

    1986-01-01

    Feeding several slurry pipes into main pipeline reduces congestion in coal mines. System based on manifold concept: feeder pipelines from each working entry joined to main pipeline that carries coal slurry out of panel and onto surface. Manifold concept makes coal-slurry haulage much simpler than existing slurry systems.

  9. Full-scale cold-flow modelling of the SRC-I slurry fired heater at Creare, Inc. : gas density and liquid rheology studies and overall data analysis

    SciTech Connect

    Mehta, D.C.; Weimer, R.F.; Crowley, C.J.; Patel, B.R.; Sam, R.G.; Wallis, G.B.

    1984-05-01

    The major conclusions are: (1) The flow regime in the heater pipe will be slug flow at the design conditions of 6- and 12-ft/sec liquid and gas superficial velocities, respectively. The pipe configuration for the design is a 1/sup 0/ upward slope. (2) Slug flow will also exist in the heater pipes at mass loadings as low as one-third the design gas and liquid velocities. (3) The expected pressure drop across the fired heater will be 25 to 50% lower than the design value. This will provide flexibility for any design modifications and still stay below the design pressure drop. (4) The expected heat transfer coefficient will be higher than the design value, thereby improving the overall heat transfer performance. (5) Based on the heat transfer data developed at Creare and the computer simulation program at ICRC, the inside wall temperature of the fired heater pipe could be controlled below 850/sup 0/F. The thick pipe walls serve as huge heat sink and are not influenced by the cyclic nature of the slug flow. (6) The presence of slug flow and a higher heat transfer coefficient maintaining the inside wall temperature below 850/sup 0/F should eliminate the possibility of coking in the fired heater pipe. (7) The results confirm the presence of slug flow at the full range of operating conditions. The expected lower pressure drop and higher heat transfer coefficient compared with the design values would improve the overall performance of the fired heater. Therefore, the results from the test program at Creare confirm the SRC-I Demonstration Plant fired heater design. Appendix 1 has been entered individually into EDB and ERA. 5 references, 1 table.

  10. Spectra and radial flow in relativistic heavy ion collisions with Tsallis statistics in a blast-wave description

    SciTech Connect

    Tang Zebo; Xu Yichun; Ruan Lijuan; Buren, Gene van; Xu Zhangbu; Wang Fuqiang

    2009-05-15

    We have implemented the Tsallis statistics in a Blast-Wave model (TBW) and applied it to midrapidity transverse-momentum spectra of identified particles measured at BNL Relativistic Heavy Ion Collider (RHIC). This new TBW function fits the RHIC data very well for p{sub T}<3 GeV/c. We observed that the collective flow velocity starts from zero in p+p and peripheral Au+Au collisions and grows to 0.470{+-}0.009c in central Au+Au collisions. The resulting (q-1) parameter, which characterizes the degree of nonequilibrium in a system, indicates an evolution from a highly nonequilibrated system in p+p collisions toward an almost thermalized system in central Au+Au collisions. The temperature and collective velocity are well described by a quadratic dependence on (q-1). Two sets of parameters in our TBW are required to describe the meson and baryon groups separately in p+p collisions while one set appears to fit all spectra in central Au+Au collisions.

  11. Slurry burner for mixture of carbonaceous material and water

    DOEpatents

    Nodd, D.G.; Walker, R.J.

    1985-11-05

    The present invention is intended to overcome the limitations of the prior art by providing a fuel burner particularly adapted for the combustion of carbonaceous material-water slurries which includes a stationary high pressure tip-emulsion atomizer which directs a uniform fuel into a shearing air flow as the carbonaceous material-water slurry is directed into a combustion chamber, inhibits the collection of unburned fuel upon and within the atomizer, reduces the slurry to a collection of fine particles upon discharge into the combustion chamber, and regulates the operating temperature of the burner as well as primary air flow about the burner and into the combustion chamber for improved combustion efficiency, no atomizer plugging and enhanced flame stability.

  12. Development and validation of a radial inflow turbine model for simulation of the SNL S-CO2 split-flow loop.

    SciTech Connect

    Vilim, R. B.

    2012-07-31

    A one-dimensional model for a radial inflow turbine has been developed for super-critical carbon dioxide (S-CO{sub 2}) Brayton cycle applications. The model accounts for the main phenomena present in the volute, nozzle, and impeller of a single-stage turbine. These phenomena include internal losses due to friction, blade loading, and angle of incidence and parasitic losses due to windage and blade-housing leakage. The model has been added as a component to the G-PASS plant systems code. The model was developed to support the analysis of S-CO{sub 2} cycles in conjunction with small-scale loop experiments. Such loops operate at less than a MWt thermal input. Their size permits components to be reconfigured in new arrangements relatively easily and economically. However, the small thermal input combined with the properties of carbon dioxide lead to turbomachines with impeller diameters of only one to two inches. At these sizes the dominant phenomena differ from those in larger more typical machines. There is almost no treatment in the literature of turbomachines at these sizes. The present work therefore is aimed at developing turbomachine models that support the task of S-CO{sub 2} cycle analysis using small-scale tests. Model predictions were compared against data from an experiment performed for Sandia National Laboratories in the split-flow Brayton cycle loop currently located at Barber-Nichols Inc. The split-flow loop incorporates two turbo-alternator-compressor (TAC) units each incorporating a radial inflow turbine and a radial flow compressor on a common shaft. The predicted thermodynamic conditions at the outlet of the turbine on the main compressor shaft were compared with measured values at different shaft speeds. Two modifications to the original model were needed to better match the experiment data. First, a representation of the heat loss from the volute downstream of the sensed inlet temperature was added. Second, an empirical multiplicative factor was

  13. Radial Inflow Turboexpander Redesign

    SciTech Connect

    William G. Price

    2001-09-24

    Steamboat Envirosystems, LLC (SELC) was awarded a grant in accordance with the DOE Enhanced Geothermal Systems Project Development. Atlas-Copco Rotoflow (ACR), a radial expansion turbine manufacturer, was responsible for the manufacturing of the turbine and the creation of the new computer program. SB Geo, Inc. (SBG), the facility operator, monitored and assisted ACR's activities as well as provided installation and startup assistance. The primary scope of the project is the redesign of an axial flow turbine to a radial inflow turboexpander to provide increased efficiency and reliability at an existing facility. In addition to the increased efficiency and reliability, the redesign includes an improved reduction gear design, and improved shaft seal design, and upgraded control system and a greater flexibility of application

  14. Rheology of sludge-slurry grouts

    SciTech Connect

    McDaniel, E. W.

    1980-10-01

    A series of rheograms was developed that relates the critical velocity (velocity where flow changes from laminar to turbulent) of a cementitious grout that incorporates a suspended sludge-slurry to the critical velocity of a reference grout made with a simulated waste solution. The sludge that is now in the Gunite waste tanks at the Oak Ridge National Laboratory (ORNL) will be suspended and pumped to the new waste storage tanks in Melton Valley. The sludge will then be blended with a cement mix base to form a grout which will be injected underground by the shale fracturing process. This report describes the materials, equipment, and techniques used in the laboratory studies to suspend sludges and mix sludge-slurry grouts that have flow properties similar to those of current shale fracturing grouts. Bentonite clay is an effective suspender in dilute NaNO/sub 3/ solutions; 15 wt % solids can be suspended with 2.0 wt % bentonite in a 0.1 M NaNO/sub 3/ solution. Other suspending materials were evaluated, but bentonite gave the best results. If a slurry grout becomes too viscous to pump, methods must be available to thin the mixture. A number of thinners, friction reducers, and plasticizers were examined. Q-Broxin, a thinner supplied by Baroid, reduced the velocity of a grout required for turbulent flow in a 5.0-cm (2-in.)-diam tube from 1.76 to 1.20 m/s (5.79 to 3.95 ft/s); FX-32C, a plasticizer supplied by Fox Industries, Inc., reduced the velocity from 1.76 to 0.75 m/s (5.6 to 2.45 ft/s).

  15. Revised FORTRAN program for calculating velocities and streamlines on the hub-shroud midchannel stream surface of an axial-, radial-, or mixed-flow turbomachine or annular duct. 2: Programmer's manual

    NASA Technical Reports Server (NTRS)

    Katsanis, T.; Mcnally, W. D.

    1977-01-01

    A FORTRAN IV computer program has been developed that obtains a detailed subsonic or shock free transonic flow solution on the hub-shroud midchannel stream surface of a turbomachine. The blade row may be fixed or rotating, and the blades may be twisted and leaned. Flow may be axial, mixed, or radial. Upstream and downstream flow variables may vary from hub to shroud, and provisions are made to correct for loss of stagnation pressure. The results include velocities, streamlines, and flow angles on the stream surface and approximate blade surface velocities.

  16. Streamline coal slurry letdown valve

    DOEpatents

    Platt, Robert J.; Shadbolt, Edward A.

    1983-01-01

    A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces.

  17. Streamline coal slurry letdown valve

    DOEpatents

    Platt, R.J.; Shadbolt, E.A.

    1983-11-08

    A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces. 5 figs.

  18. Medical ice slurry production device

    DOEpatents

    Kasza, Kenneth E.; Oras, John; Son, HyunJin

    2008-06-24

    The present invention relates to an apparatus for producing sterile ice slurries for medical cooling applications. The apparatus is capable of producing highly loaded slurries suitable for delivery to targeted internal organs of a patient, such as the brain, heart, lungs, stomach, kidneys, pancreas, and others, through medical size diameter tubing. The ice slurry production apparatus includes a slurry production reservoir adapted to contain a volume of a saline solution. A flexible membrane crystallization surface is provided within the slurry production reservoir. The crystallization surface is chilled to a temperature below a freezing point of the saline solution within the reservoir such that ice particles form on the crystallization surface. A deflector in the form of a reciprocating member is provided for periodically distorting the crystallization surface and dislodging the ice particles which form on the crystallization surface. Using reservoir mixing the slurry is conditioned for easy pumping directly out of the production reservoir via medical tubing or delivery through other means such as squeeze bottles, squeeze bags, hypodermic syringes, manual hand delivery, and the like.

  19. Comparative testing of slurry monitors

    SciTech Connect

    Hylton, T.D.; Bayne, C.K.; Anderson, M.S.; Van Essen, D.C.

    1998-05-01

    The US Department of Energy (DOE) has millions of gallons of radioactive liquid and sludge wastes that must be retrieved from underground storage tanks, transferred to treatment facilities, and processed to a final waste form. The wastes will be removed from the current storage tanks by mobilizing the sludge wastes and mixing them with the liquid wastes to create slurries. Each slurry would then be transferred by pipeline to the desired destination. To reduce the risk of plugging a pipeline, the transport properties (e.g., density, suspended solids concentration, viscosity, particle size range) of the slurry should be determined to be within acceptable limits prior to transfer. These properties should also be monitored and controlled within specified limits while the slurry transfer is in progress. The DOE issued a call for proposals for developing on-line instrumentation to measure the transport properties of slurries. In response to the call for proposals, several researchers submitted proposals and were funded to develop slurry monitoring instruments. These newly developed DOE instruments are currently in the prototype stage. Before the instruments were installed in a radioactive application, the DOE wanted to evaluate them under nonradioactive conditions to determine if they were accurate, reliable, and dependable. The goal of this project was to test the performance of the newly developed DOE instruments along with several commercially available instruments. The baseline method for comparison utilized the results from grab-sample analyses.

  20. Time dependent behavior of impact angle in turbulkent pipe flows experience erosion

    NASA Astrophysics Data System (ADS)

    Guzman, Amador; Oyarzun, Diego; Walczak, Magdalena; Aguirre, Javiera

    Erosion-corrosion in pipe systems transporting slurry turbulent flows is of a great importance in industrial and mining applications, where large volumes of suspended solids are sent up to hundreds of kilometers, to be further processed. The slurry is typically sent over large diameter steel pipes, which not always have an anti-abrasion coating. During the transport, the thickness of the pipe diminishes and eventually leaks and breaks, due to the combined effects of wear and corrosion. The processes of pipe degradation are further enhanced by the content of the slurry electrolytes that might switch from neutral to aggressive. The understanding of these processes in terms of operational parameters is critical for anticipating and mitigating a catastrophic outcome. This paper describes turbulent flow numerical simulations in a slurry transporting steel pipe with an emphasis on the correlation between the time dependent impact angle in the vicinity of the steel pipe and the rate of material loss. Full numerical simulations in a 3D long domain by using an Eulerian -Eulerian two phase flow approach coupled to a κ-epsilon turbulent model are performed for different solid particle concentration and flow velocity and compared to existing experimental and numerical results for validation with and without gravity. Time-dependent axisymmetric turbulent flow simulations are performed for determining both the time dependent behavior of the axial and radial velocities near the pipe wall and the impact angle. Finantial support from Conicyt through the Fondecyt proposal 1141107 is acknowledged.

  1. ADVANCED COMPUTATIONAL MODEL FOR THREE-PHASE SLURRY REACTORS

    SciTech Connect

    Goodarz Ahmadi

    2000-11-01

    In the first year of the project, solid-fluid mixture flows in ducts and passages at different angle of orientations were analyzed. The model predictions are compared with the experimental data and good agreement was found. Progress was also made in analyzing the gravity chute flows of solid-liquid mixtures. An Eulerian-Lagrangian formulation for analyzing three-phase slurry flows in a bubble column is being developed. The approach uses an Eulerian analysis of gas liquid flows in the bubble column, and makes use of the Lagrangian particle tracking procedure to analyze the particle motions. Progress was also made in developing a rate dependent thermodynamically consistent model for multiphase slurry flows in a state of turbulent motion. The new model includes the effect of phasic interactions and leads to anisotropic effective phasic stress tensors. Progress was also made in measuring concentration and velocity of particles of different sizes near a wall in a duct flow. The formulation of a thermodynamically consistent model for chemically active multiphase solid-fluid flows in a turbulent state of motion was also initiated. The general objective of this project is to provide the needed fundamental understanding of three-phase slurry reactors in Fischer-Tropsch (F-T) liquid fuel synthesis. The other main goal is to develop a computational capability for predicting the transport and processing of three-phase coal slurries. The specific objectives are: (1) To develop a thermodynamically consistent rate-dependent anisotropic model for multiphase slurry flows with and without chemical reaction for application to coal liquefaction. Also to establish the material parameters of the model. (2) To provide experimental data for phasic fluctuation and mean velocities, as well as the solid volume fraction in the shear flow devices. (3) To develop an accurate computational capability incorporating the new rate-dependent and anisotropic model for analyzing reacting and

  2. ADVANCED COMPUTATIONAL MODEL FOR THREE-PHASE SLURRY REACTORS

    SciTech Connect

    Goodarz Ahmadi

    2001-10-01

    In the second year of the project, the Eulerian-Lagrangian formulation for analyzing three-phase slurry flows in a bubble column is further developed. The approach uses an Eulerian analysis of liquid flows in the bubble column, and makes use of the Lagrangian trajectory analysis for the bubbles and particle motions. An experimental set for studying a two-dimensional bubble column is also developed. The operation of the bubble column is being tested and diagnostic methodology for quantitative measurements is being developed. An Eulerian computational model for the flow condition in the two-dimensional bubble column is also being developed. The liquid and bubble motions are being analyzed and the results are being compared with the experimental setup. Solid-fluid mixture flows in ducts and passages at different angle of orientations were analyzed. The model predictions were compared with the experimental data and good agreement was found. Gravity chute flows of solid-liquid mixtures is also being studied. Further progress was also made in developing a thermodynamically consistent model for multiphase slurry flows with and without chemical reaction in a state of turbulent motion. The balance laws are obtained and the constitutive laws are being developed. Progress was also made in measuring concentration and velocity of particles of different sizes near a wall in a duct flow. The technique of Phase-Doppler anemometry was used in these studies. The general objective of this project is to provide the needed fundamental understanding of three-phase slurry reactors in Fischer-Tropsch (F-T) liquid fuel synthesis. The other main goal is to develop a computational capability for predicting the transport and processing of three-phase coal slurries. The specific objectives are: (1) To develop a thermodynamically consistent rate-dependent anisotropic model for multiphase slurry flows with and without chemical reaction for application to coal liquefaction. Also establish the

  3. Roles of additives and surface control in slurry atomization

    SciTech Connect

    Tsai, S.C.

    1990-01-01

    This report focuses on the effects of interparticle forces on the rheology and airblast atomization of micronized coal water slurry (CWS). We found that the CWS flow behavior index is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The former intensifies as the Hamaker constant increases and the interparticle distance reduces while the latter increases as the particle surface charge density increases. The interparticle attraction causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior. In contrast, the interparticle repulsion prevents particle aggregation and thus leads to Newtonian behavior. Both atomized at low atomizing air pressures (less than 270 kPa) using twin-fluid jet atomizers of various distributor designs. We found that the atomized drop sizes of micronized coal water slurries substantially decrease as the atomizing air pressure exceeds a threshold value. The effects of coal volume fraction, coal particle surface charge, liquid composition and liquid viscosity on slurry atomization can be accounted for by their effects on slurry rheology. 26 refs.

  4. Critical parameters for coarse coal underground slurry haulage systems

    NASA Technical Reports Server (NTRS)

    Maynard, D. P.

    1981-01-01

    Factors are identified which must be considered in meeting the requirements of a transportation system for conveying, in a pipeline, the coal mined by a continuous mining machine to a storage location neat the mine entrance or to a coal preparation plant located near the surface. For successful operation, the slurry haulage the system should be designed to operated in the turbulent flow regime at a flow rate at least 30% greater than the deposition velocity (slurry flow rate at which the solid particles tend to settle in the pipe). The capacity of the haulage system should be compatible with the projected coal output. Partical size, solid concentration, density, and viscosity of the suspension are if importance as well as the selection of the pumps, pipes, and valves. The parameters with the greatest effect on system performance ar flow velocity, pressure coal particle size, and solids concentration.

  5. Radial cold trap

    DOEpatents

    Grundy, Brian R.

    1981-01-01

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume.

  6. Radial cold trap

    DOEpatents

    Grundy, B.R.

    1981-09-29

    The radial cold trap comprises a housing having a plurality of mesh bands disposed therein. The mesh bands comprise concentrically arranged bands of mesh with the mesh specific surface area of each band increasing from the outermost mesh band to the innermost mesh band. An inlet nozzle is attached to the outside section of the housing while an outlet nozzle is attached to the inner portion of the housing so as to be concentrically connected to the innermost mesh band. An inlet baffle having orifices therein may be disposed around the outermost mesh band and within the housing for directing the flow of the fluid from the inlet nozzle to the outermost mesh band in a uniform manner. The flow of fluid passes through each consecutive mesh band and into the outlet nozzle. The circular pattern of the symmetrically arranged mesh packing allows for better utilization of the entire cold trap volume. 2 figs.

  7. Rheological properties essential for the atomization of coal water slurries (CWS). Quarterly progress report, March 15, 1995--June 15, 1995

    SciTech Connect

    Ohene, F.

    1995-10-01

    The analysis of pipeline transportation of highly concentrated suspensions such as coal-water slurries, can exhibit several flow characteristics depending on the concentration and the physical parameters of the dispersed phase. Experiments were conducted for coal-water slurries flows in a series of horizontal capillary tubes of diameters 0.8, 1.5 and 3.0 mm and 100 mm in length, in order to investigate the effect of concentration, pressure drop, and the transitional Reynolds number from laminar to turbulent flow in a homogeneous slurry. The solid concentration was varied from 15% to 63% in 0.1% xanthum gum solution. Pressure drop and the volume flow measurement were made using HVA-6 Capillary viscometer. The Reynolds numbers obtained were found to be dependent on the slurry concentration and the viscosity of the slurry mixture, but independent of the capillary diameter.

  8. Coal-oil slurry preparation

    DOEpatents

    Tao, John C.

    1983-01-01

    A pumpable slurry of pulverized coal in a coal-derived hydrocarbon oil carrier which slurry is useful as a low-ash, low-sulfur clean fuel, is produced from a high sulfur-containing coal. The initial pulverized coal is separated by gravity differentiation into (1) a high density refuse fraction containing the major portion of non-coal mineral products and sulfur, (2) a lowest density fraction of low sulfur content and (3) a middlings fraction of intermediate sulfur and ash content. The refuse fraction (1) is gasified by partial combustion producing a crude gas product from which a hydrogen stream is separated for use in hydrogenative liquefaction of the middlings fraction (3). The lowest density fraction (2) is mixed with the liquefied coal product to provide the desired fuel slurry. Preferably there is also separately recovered from the coal liquefaction LPG and pipeline gas.

  9. Microstructure Evolution and Rheological Behavior of Cooling Slope Processed Al-Si-Cu-Fe Alloy Slurry

    NASA Astrophysics Data System (ADS)

    Das, Prosenjit; Samanta, Sudip K.; Bera, Supriya; Dutta, Pradip

    2016-05-01

    In the present work, microstructure evolution during semi-solid slurry generation of Al-Si-Cu-Fe alloy, using a cooling slope, was studied and the effect of microstructural morphology of the slurry on its rheological behavior was investigated. Microstructure evolution during melt flow along the slope was studied by extracting samples from various locations of the slope and performing rapid oil quenching experiments. Quantitative investigation was performed to evaluate primary phase shape and size for different process conditions of the semi-solid slurry, and subsequently rheological investigations were performed to correlate slurry morphology with its flow behavior. Three different types of rheological experiments were performed: isothermal test, shear jump test, and shear time test, in order to investigate rheological behavior of the semi-solid slurry. In addition, effect of melt treatment, by adding modifier (0.1 wt pct of Al-10Sr) and grain refiner (0.15 wt pct of Al-5Ti-1B), on the microstructure evolution during slurry generation, flow behavior of the slurry, and intermetallics formation was studied.

  10. Loose abrasive slurries for optical glass lapping

    SciTech Connect

    Neauport, Jerome; Destribats, Julie; Maunier, Cedric; Ambard, Chrystel; Cormont, Philippe; Pintault, B.; Rondeau, Olivier

    2010-10-20

    Loose abrasive lapping is widely used to prepare optical glass before its final polishing. We carried out a comparison of 20 different slurries from four different vendors. Slurry particle sizes and morphologies were measured. Fused silica samples were lapped with these different slurries on a single side polishing machine and characterized in terms of surface roughness and depth of subsurface damage (SSD). Effects of load, rotation speed, and slurry concentration during lapping on roughness, material removal rate, and SSD were investigated.

  11. Revised FORTRAN program for calculating velocities and streamlines on the hub-shroud midchannel stream surface of an axial-, radial-, or mixed-flow turbomachine or annular duct. 1: User's manual

    NASA Technical Reports Server (NTRS)

    Katsanis, T.; Mcnally, W. D.

    1977-01-01

    A FORTRAN 4 computer program was developed that obtains a detailed subsonic or shock-free transonic flow solution on the hub-shroud midchannel stream surface of a turbomachine. The blade row may be fixed or rotating, and the blades may be twisted and leaned. Flow may be axial, mixed, or radial. Upstream and downstream flow variables may vary from hub to shroud, and provision is made to correct for loss of stagnation pressure. The results include velocities, streamlines, and flow angles on the stream surface as well as approximate blade surface velocities. Subsonic solutions are obtained by a finite-difference, stream-function solution. Transonic solutions are obtained by a velocity-gradient method that uses information from a finite-difference, stream-function solution at a reduced mass flow.

  12. Measurement of the Critical Deposition Velocity in Slurry Transport through a Horizontal Pipe

    SciTech Connect

    Erian, Fadel F.; Furfari, Daniel J.; Kellogg, Michael I.; Park, Walter R.

    2001-03-01

    Critical Deposition Velocity (CDV) is an important design and operational parameter in slurry transport. Almost all existing correlations that are used to predict this parameter have been obtained experimentally from slurry transport tests featuring single solid species in the slurry mixture. No correlations have been obtained to describe this parameter when the slurry mixture contains more than one solid species having a wide range of specific gravities, particle size distributions, and volume concentrations within the overall slurry mixture. There are no physical or empirical bases that can justify the extrapolation or modification of the existing single species correlations to include all these effects. New experiments must be carried out to obtain new correlations that would be suited for these types of slurries, and that would clarify the mechanics of solids deposition as a function of the properties of the various solid species. Our goal in this paper is to describe a robust experimental technique for the accurate determination of the critical deposition velocity associated with the transport of slurries in horizontal or slightly inclined pipes. Because of the relative difficulty encountered during the precise determination of this useful operational parameter, it has been the practice to connect it with some transitional behavior of more easily measurable flow parameters such as the pressure drop along the slurry pipeline. In doing so, the critical deposition velocity loses its unique and precise definition due to the multitude of factors that influence such transitional behaviors. Here, data has been obtained for single species slurries made up of washed garnet and water and flowing through a 1- inch clear pipe. The selected garnet had a narrow particle size distribution with a mean diameter of 100 mm, approximately. The critical deposition velocity was measured for garnet/water slurries of 10, 20, and 30 percent solids concentration by volume.

  13. DEMONSTRATION BULLETIN: SLURRY BIODEGRADATION, International Technology Corporation

    EPA Science Inventory

    This technology uses a slurry-phase bioreactor in which the soil is mixed with water to form a slurry. Microorganisms and nutrients are added to the slurry to enhance the biodegradation process, which converts organic wastes into relatively harmless byproducts of microbial metabo...

  14. Supersonic coal water slurry fuel atomizer

    DOEpatents

    Becker, Frederick E.; Smolensky, Leo A.; Balsavich, John

    1991-01-01

    A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

  15. Formulation of slurries for slurry-fed coal gasifiers

    SciTech Connect

    Butcher, T.A.; Sapienza, R.S.; Krishna, C.R.; O'Hare, T.E.; Saunders, J.; Celebi, Y.

    1986-05-01

    A 100 MW integrated gasification/combined cycle generating plant was recently put into operation at the Cool Water generating station of Southern California Edison Co. Coal is fed into the gasifier as a coal water slurry. This paper reports on a study on the slurryability of candidate gasifier coals and slurry formulation options for use in systems of this type. The ten candidate coals studied ranged in equilibrium moisture from 1 to 13%. A ranking was made of the relative slurryability of the coals under two cases, with and without an added surfactant. Slurry formulation studies included the effects of size distribution, acid leaching, additional physical cleaning - both gravity separation and froth flotation, selected anionic and nonionic surfactants, pH, and oxidation to simulate weathering. Slurry viscosity can be lowered using optimized size distributions which are broader than those achieved in typical grinders. Blending the coarse and fine sizes used was explored as an approach toward achieving higher loadings both with and without surfactants. Acid leaching was found to be a very effective method of reducing slurry conductivity, which could promote dispersion of the particles. The effect on viscosity for the specific coals studied, however, was not significant. Similarly, additional physical cleaning was found to have no significant effect on coal equilibrium moisture or loadings on a weight basis. The study has recommended that significant loading increases could be achieved using low concentrations of surfactants alone. This is particularly true for the higher rank coals, which have lower additive demand, and have a greater viscosity reduction at the optimum additive concentration. 13 refs., 19 figs., 16 tabs.

  16. Tribological properties of coal slurries

    NASA Technical Reports Server (NTRS)

    Fusaro, Robert L.; Schrubens, Dale L.

    1987-01-01

    A pin-on-disk tribometer was used to study the tribological properties of methyl alcohol-coal slurries. Friction coefficients, steel pin wear rates and wear surface morphological studies were conducted on AISI 440C HT and M-50 bearing steels which were slid dry and in solutions of methyl alcohol, methyl alcohol-fine coal particles, and methyl alcohol-fine coal particles-flocking additive. The latter was an oil derived from coal and originally intended to be added to the coal slurry to improve the sedimentation and rheology properties. The results of this study indicated that the addition of the flocking additive to the coal slurry markedly improved the tribological properties, especially wear. In addition, the type of steel was found to be very important in determining the type of wear that took place. Cracks and pits were found on the M-50 steel pin wear surfaces that slid in the coal slurries while 440C HT steel pins showed none.

  17. The secondary slurry-zinc/air battery

    SciTech Connect

    Sierra Alcazar, H.B.; Nguyen, P.D.; Mason, G.E.; Pinoli, A.A. )

    1989-07-01

    The rechargeability of the slurry-Zn/air battery was demonstrated with a practical recharge cell that requires minimal hydraulic and mechanical energy for operation. A dendritic Zn was deposited on a Mg plate substrate from which it was easily, periodically and automatically scraped to regenerate dendritic Zn slurries. Excellent discharge results were obtained with the regenerated dendritic Zn slurry, comparable to those obtained with slurries made with mixtures of Zn powder. The dendritic Zn slurry allowed, however, twice the utilization of Zn. 13 refs., 24 figs., 2 tabs.

  18. Assessment of natural fluorescence as a tracer of diffuse agricultural pollution from slurry spreading on intensely-farmed grasslands.

    PubMed

    Naden, Pamela S; Old, Gareth H; Eliot-Laize, Caroline; Granger, Steve J; Hawkins, Jane M B; Bol, Roland; Haygarth, Phil

    2010-03-01

    The value of natural fluorescence in tracing diffuse pollution, in liquid phase, following slurry application to land was assessed by field experiment using twelve one hectare lysimeters on a heavy clay soil in Devon, UK, during autumn 2007. A strong linear relationship was found between natural fluorescence intensity and slurry concentration. The ratio of indices of tryptophan-like and fulvic/humic-like fluorescence (TI:FI) varied between 2 and 5 for a range of slurries sampled from Devon farms and allowed slurry to be distinguished from uncontaminated drainage waters (TI:FI<1). Incidental losses of slurry, indicated by significantly enhanced TI:FI ratios, high TI and high ammonium levels, occurred via the drain flow pathway of the drained lysimeters during the first small event following slurry-spreading. The maximum estimated loss from a single lysimeter was 2-8kg or 0.004-0.016% of the applied slurry. In the second larger storm event, some five weeks later, significantly enhanced TI:FI ratios in the drain flows were not associated with high TI but with high nitrate levels and, compared to the earlier storm, an increase in the humification index. This implies the loss of slurry decomposition products during this event but further work is needed to validate this. There was no significant enhancement of TI:FI in the surface/throughflow pathways of the drained or undrained lysimeters in either of the events. The observed change over a period of weeks in the strength and nature of the fluorescence signal from spread slurry restricts quantification of slurry losses to those immediately after slurry spreading. Nonetheless, this study demonstrates the utility of fluorescence as an indicator of slurry in drainage waters and the importance of field drains in diffuse agricultural pollution. PMID:20018337

  19. Rheological properties of the product slurry of the Nitrate to Ammonia and Ceramic (NAC) process

    SciTech Connect

    Muguercia, I.; Yang, G.; Ebadian, M.A.; Lee, D.D.; Mattus, A.J.; Hunt, R.D.

    1995-03-01

    The Nitrate to Ammonia and Ceramic (NAC) process is an innovative technology for immobilizing the liquid from Low Level radioactive Waste (LLW). An experimental study was conducted to measure the rheological properties of the pipe flow of the NAC product slurry. Test results indicate that the NAC product slurry has a profound rheological behavior. At low solids concentration, the slurry exhibits a typical dilatant fluid (or shear thinning)fluid. The transition from dilatant fluid to pseudo-plastic fluid will occur at between 25% to 30% solids concentration in temperature ranges of 50--80{degree}C. Correlation equations are developed based on the test data.

  20. Hydrodynamic models for slurry bubble column reactors

    SciTech Connect

    Gidaspow, D.

    1995-12-31

    The objective of this investigation is to convert a {open_quotes}learning gas-solid-liquid{close_quotes} fluidization model into a predictive design model. This model is capable of predicting local gas, liquid and solids hold-ups and the basic flow regimes: the uniform bubbling, the industrially practical churn-turbulent (bubble coalescence) and the slugging regimes. Current reactor models incorrectly assume that the gas and the particle hold-ups (volume fractions) are uniform in the reactor. They must be given in terms of empirical correlations determined under conditions that radically differ from reactor operation. In the proposed hydrodynamic approach these hold-ups are computed from separate phase momentum balances. Furthermore, the kinetic theory approach computes the high slurry viscosities from collisions of the catalyst particles. Thus particle rheology is not an input into the model.

  1. ANALYSIS OF VENTING OF A RESIN SLURRY

    SciTech Connect

    Laurinat, J.; Hensel, S.

    2012-03-27

    A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture upon rupture of the disk. It is postulated that the maximum pressure at the end of this expansion is limited by energy minimization to approximately 1.5 times the rupture disk burst pressure. The magnitude of this pressure increase is consistent with the measured pressure transients. The results of this analysis demonstrate the need to allow for a margin between the design pressure and the rupture disk burst pressure in similar applications.

  2. NASA contributions to radial turbine aerodynamic analyses

    NASA Technical Reports Server (NTRS)

    Glassman, A. J.

    1980-01-01

    A brief description of the radial turbine and its analysis needs is followed by discussions of five analytical areas; design geometry and performance, off design performance, blade row flow, scroll flow, and duct flow. The functions of the programs, areas of applicability, and limitations and uncertainties are emphasized. Both past contributions and current activities are discussed.

  3. Geosynthetic tubes for confining pressurized slurry: Some design aspects

    SciTech Connect

    Leshchinsky, D.; Ling, H.I.; Leshchinsky, O.; Gilbert, P.A.

    1996-08-01

    This paper deals with geosynthetic tubes that are made of several geosynthetic sheets sewn together to form a shell capable of confining pressurized slurry. The slurry is sufficiently fluid so that it is possible to hydraulically fill the tube. After pumping the slurry in, the geosynthetic shell acts as a cheese cloth, allowing seepage of liquid out and retaining the solid particles. The availability of a wide selection of geosynthetics in terms of strength, durability, and permeability enables the use of hydraulically filled tubes in many applications, some of which may be considered critical (e.g., encapsulate contaminated soil). This paper presents an overview of an analysis to calculate both stresses in the geosynthetic and geometry of the tube. It also verifies the correctness and validity of the results obtained from a computer program developed to solve the problem. An instructive parametric study implies that the most critical factor needed to assure successful construction is the pumping pressure; a slight accidental increase in this pressure may result in a very significant stress increase in the encapsulating geosynthetic. Pressure increase beyond a certain level, however, has little influence on the storage capacity of the tube. Guidance in selecting an adequate geosynthetic, including partial safety factors and filtration properties, is also presented. Design aspects associated with required spacing of inlets and head loss of the slurry as it flows through the tube are considered outside the scope of this paper.

  4. Bench Scale Test of Absorption Slurry-ice Maker

    NASA Astrophysics Data System (ADS)

    Sasao, Hiroyuki; Yoshida, Takashi

    Slurry ice system is desirable as cold heat source for air conditioning, because it requires less conveyance power or less pipe size. On the other hand, recently absorption refrigerator is reevaluated because it can utilize various types of waste heat and it does not use fluorocarbon refrigerant. But it had been regarded to be difficult to make ice by absorption refrigerator because the refrigerant is water. However making slurry ice is possible, of cource, if the slurry ice generated by partial freezing of water is continuously taken away from the evaporator. This method was certified experimentally with a bench scale model. For ice making continuously, ice had not to be frozen stiff at water surface or inside wall of the evaporator. Then refrigerant water in the evaporator was raised swirl flow. And inside wall of the evaporator was finished by water repellent coating, and heated from outside wall. This slurry ice was adaptable to hydraulic transportation, because ice was needle crystal with about 5 mm length and ice temperature was 0°C.

  5. Radial head fracture - aftercare

    MedlinePlus

    Elbow fracture - radial head - aftercare ... the radius bone, just below your elbow. A fracture is a break in your bone. The most common cause of a radial head fracture is falling with an outstretched arm.

  6. Intraoperative hemodynamic evaluation of the radial and ulnar arteries during free radial forearm flap procedure.

    PubMed

    Lorenzetti, Fulvio; Giordano, Salvatore; Suominen, Erkki; Asko-Seljavaara, Sirpa; Suominen, Sinikka

    2010-02-01

    The purpose of this prospective study was to assess the blood flow of the radial and ulnar arteries before and after radial forearm flap raising. Twenty-two patients underwent radial forearm microvascular reconstruction for leg soft tissue defects. Blood flow of the radial, ulnar, and recipient arteries was measured intraoperatively by transit-time and ultrasonic flowmeter. In the in situ radial artery, the mean blood flow was 60.5 +/- 47.7 mL/min before, 6.7 +/- 4.1 mL/min after raising the flap, and 5.8 +/- 2.0 mL/min after end-to-end anastomosis to the recipient artery. In the ulnar artery, the mean blood flow was 60.5 +/- 43.3 mL/min before harvesting the radial forearm flap and significantly increased to 85.7 +/- 57.9 mL/min after radial artery sacrifice. A significant difference was also found between this value and the value of blood flow in the ulnar and radial arteries pooled together ( P < 0.05). The vascular resistance in the ulnar artery decreased significantly after the radial artery flap raising (from 2.7 +/- 3.1 to 1.9 +/- 2.2 peripheral resistance units, P = 0.010). The forearm has a conspicuous arterial vascularization not only through the radial and ulnar arteries but also through the interosseous system. The raising of the radial forearm flap increases blood flow and decreases vascular resistance in the ulnar artery. PMID:19902406

  7. Coal slurries: An environmental bonus

    SciTech Connect

    Basta, N.; Moore, S.; Ondrey, G.

    1994-05-01

    Developers and promoters of coal-water slurries and similar CWF (coal-water fuel) technologies have had a hard time winning converts since they unveiled their first commercial processes in the 1970s. The economic appeal of such processes, marginal at best, varies with the price of oil. Nevertheless, the technology is percolating, as geopolitics and environmental pressures drive new processes. Such fuels are becoming increasingly important to coal-rich, oil-poor nations such as China, as they attempt to build an onshore fuel supply. Meanwhile, improvements are changing the way coal-fired processes are viewed. Where air pollution regulations once discouraged the use of coal fuels, new coal processes have been developed that cut nitrous oxides (NOx) emissions and provide a use for coal fines, previously viewed as waste. The latest developments in the field were all on display at the 19th International Technical Conference on Coal Utilization and Fuel Systems, held in Clearwater, Fla., on March 21--24. At this annual meeting, sponsored by the Coal and Slurry Technology Association, (Washington, D.C.) and the Pittsburgh Energy Technology Center of the US Dept. of Energy (PETC), some 200 visitors from around the work gathered to discuss the latest developments in coal slurry utilization--new and improved processes, and onstream plants. This paper presents highlights from the conference.

  8. Indian Creek-AML: Coal slurry reclamation (Kansas case history)

    SciTech Connect

    Witthar, S.R.

    1998-12-31

    Black and Veatch, assisted by Jack Nawrot, developed conceptual and final designs and provided construction assistance to create grasslands and wetlands in order to reclaim an abandoned coal mine for the state of Kansas. The mine included spoils, a coal refuse dump, and slurry pond in the Indian Creek drainage basin in east central Kansas. The Indian Creek flowed from an off-site abandoned mine and through the coal slurry pond where its waters became more polluted. The intent of the reclamation project was to improve water quality and create a wildlife refuge. The coal refuse was covered and seeded with a diversity of vegetation including several grasses and legume. The slurry pond was developed into a series of large wetland cells to improve water quality. Prior to reclamation, the water leaving the site had a typical pH of 3.3, ranging from 2.4 to 5.6, an iron content which typically over 22 mg/L and ranging over 100 mg/L, and contained large amounts of coal slurry. The acid sediment in the slurry killed fish and caused visible damage to a new large concrete box culvert several miles downstream of the site. Post-reclamation water quality leaving the Indian Creek site showed immediate improvement even before vegetation was reestablished. The existing wetland treatment systems have been successfully treating water for over seven years with the pH of the water leaving the wetlands above 7 and soluble iron content less than 1 mg/L. Fish in the constructed wetlands support waterfowl which now nest onsite.

  9. High temperature well bore cement slurry

    SciTech Connect

    Nahm, J.J.W.; Vinegar, H.J.; Karanikas, J.M.; Wyant, R.E.

    1993-07-13

    A low density well bore cement slurry composition is described suitable for cementing well bores with high reservoir temperatures comprising: (a) a high alumina cement in an amount of about 40 pounds per barrel of slurry or greater: (b) graphite in an amount greater than about one quarter, by volume, of the solids in the cement slurry; and (c) and a carrier fluid comprising drilling mud.

  10. Additive for deep-well cement slurries

    SciTech Connect

    Hubner, W.; Schroers, O.; Sladeck, H.J.

    1982-07-20

    An additive is disclosed for deep-well cement slurries comprising a water soluble anionic copolymer having a molecular weight from about 50,000 to 500,000 and comprising about 1 to 60 mole % of anionic structural units and about 99 to 40 mole % of nonanionic structural units. A preferred additive comprises a terpolymer of acrylamide, sodium acrylate and sodium vinylsulphonate. The additives retard the setting action of the slurry, stabilize the slurry, prevent the swelling of clays and are resistant to electrolytes which would accelerate setting and seepage of water from the slurry.

  11. BOILING SLURRY REACTOR AND METHOD FO CONTROL

    DOEpatents

    Petrick, M.; Marchaterre, J.F.

    1963-05-01

    The control of a boiling slurry nuclear reactor is described. The reactor consists of a vertical tube having an enlarged portion, a steam drum at the top of the vertical tube, and at least one downcomer connecting the steam drum and the bottom of the vertical tube, the reactor being filled with a slurry of fissionabie material in water of such concentration that the enlarged portion of the vertical tube contains a critical mass. The slurry boils in the vertical tube and circulates upwardly therein and downwardly in the downcomer. To control the reactor by controlling the circulation of the slurry, a gas is introduced into the downcomer. (AEC)

  12. Lithium batteries with organic slurry cathodes

    SciTech Connect

    Bruder, A.H.

    1984-08-21

    Electrical cells and batteries having lithium anodes and cathodes comprising an organic slurry of MnO/sub 2/ and carbon particles in an organic solvent in contact with a conductive plastic current collector, and a method of making the cathodes comprising the steps of heating MnO/sub 2/ to remove absorbed and adsorbed water and water of crystallization, cooling the dehydrated MnO/sub 2/, dispersing the cooled and dehydrated MnO/sub 2/ in an anhydrous solvent to form a slurry, depositing the slurry in discrete cathode patches on cell component substrates, and sealing the slurry patches into cells having substantially gas impervious cell enveloping boundaries.

  13. Coal transportation: slurry pipelines vs the railroads

    SciTech Connect

    Not Available

    1983-03-01

    Increased demand for coal has caused coal producers to consider new methods of transporting it via slurry pipelines. The railroads currently transport most of the coal. Today there is a controversy between the railroads and slurry pipeline proponents, and slurry proponents argue that federal eminent domain legislation is needed to make pipelines feasible. Not all anti-slurry opposition is from the railroads. Because these systems require large amounts of water to push the coal through the lines, questions arise as to the harm this might do to the water table. This is a particularly critical issue in the West, where water is a precious resource.

  14. An experimental investigation of the thermal/fluid properties of the nitrate to ammonia and ceramic (NAC) product slurry

    SciTech Connect

    Muguercia, I.; Lagos, L.; Yang, G.; Li, W.; Ebadian, M.A.; Mattus, A.J.; Lee, D.D.; Walker, J.W.; Hunt, R.D.

    1994-12-31

    Recently, a new immobilization technique for LLW, the Nitrate to Ammonia and Ceramic (NAC) process, has been developed. Instead of mixing the liquid waste form directly with the cement to make concrete blocks, the NAC process eliminates the nitrate from the LLW by converting it to ammonia gas. Aluminum particles are used as a reductant to complete this conversion. The final product of the NAC process is gibbsite, which can be further sintered to a ceramic waste form. Experimental tests are conducted to measure the apparent viscosity, the pressure drop, and the heat transfer coefficient of the pipe flow of the Nitrate to Ammonia and Ceramic (NAC) process product slurry. The tests indicate that the NAC product slurry exhibits a typical pseudoplastic fluid behavior. The pressure drop in the pipe flow is a function of the Reynolds number and the slurry temperature. The results also indicate that at a low slurry temperature, the slurry is uniformly heated peripherally. At a high slurry temperature, however, the slurry may be thermally stratified. In a straight pipe, the Nusselt number is reduced as the slurry temperature increases.

  15. Novel Integration Radial and Axial Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth; Brown, Gary

    2000-01-01

    Typically, fully active magnetically suspended systems require one axial and two radial magnetic bearings. Combining radial and axial functions into a single device allows for more compact and elegant packaging. Furthermore, in the case of high-speed devices such as energy storage flywheels, it is beneficial to minimize shaft length to keep rotor mode frequencies as high as possible. Attempts have been made to combine radial and axial functionality, but with certain drawbacks. One approach requires magnetic control flux to flow through a bias magnet reducing control effectiveness, thus resulting in increased resistive losses. This approach also requires axial force producing magnetic flux to flow in a direction into the rotor laminate that is undesirable for minimizing eddy-current losses resulting in rotational losses. Another approach applies a conical rotor shape to what otherwise would be a radial heteropolar magnetic bearing configuration. However, positional non-linear effects are introduced with this scheme and the same windings are used for bias, radial, and axial control adding complexity to the controller and electronics. For this approach, the amount of axial capability must be limited. It would be desirable for an integrated radial and axial magnetic bearing to have the following characteristics; separate inputs for radial and axial control for electronics and control simplicity, all magnetic control fluxes should only flow through their respective air gaps and should not flow through any bias magnets for minimal resistive losses, be of a homopolar design to minimize rotational losses, position related non-linear effects should be minimized, and dependent upon the design parameters, be able to achieve any radial/axial force or power ratio as desired. The integrated radial and axial magnetic bearing described in this paper exhibits all these characteristics. Magnetic circuit design, design equations, and magnetic field modeling results will be presented.

  16. Novel Integrated Radial and Axial Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth A.; Brown, Gary L.; Powers, Edward I. (Technical Monitor)

    2000-01-01

    Typically, fully active magnetically suspended systems require one axial and two radial magnetic bearings. Combining radial and axial functions into a single device allows for more compact and elegant packaging. Furthermore, in the case of high-speed devices such as energy storage flywheels, it is beneficial to minimize shaft length to keep rotor mode frequencies as high as possible. Attempts have been made to combine radial and axial functionality, but with certain drawbacks. One approach requires magnetic control flux to flow through a bias magnet reducing control effectiveness, thus resulting in increased resistive losses. This approach also requires axial force producing magnetic flux to flow in a direction into the rotor laminate that is undesirable for minimizing eddy-current losses resulting in rotational losses. Another approach applies a conical rotor shape to what otherwise would be a radial heteropolar magnetic bearing configuration. However, positional non-linear effects are introduced with this scheme and the same windings are used for bias, radial, and axial control adding complexity to the controller and electronics. For this approach, the amount of axial capability must be limited. It would be desirable for an integrated radial and axial magnetic bearing to have the following characteristics, separate inputs for radial and axial control for electronics and control simplicity, all magnetic control fluxes should only flow through their respective air gaps and should not flow through any bias magnets for minimal resistive losses, be of a homopolar design to minimize rotational losses, position related non-linear effects should be minimized, and dependent upon the design parameters, be able to achieve any radial/axial force or power ratio as desired. The integrated radial and axial magnetic bearing described in this paper exhibits all these characteristics. Magnetic circuit design, design equations, and analysis results will be presented.

  17. ADVANCED COMPUTATIONAL MODEL FOR THREE-PHASE SLURRY REACTORS

    SciTech Connect

    Goodarz Ahmadi

    2004-10-01

    In this project, an Eulerian-Lagrangian formulation for analyzing three-phase slurry flows in a bubble column was developed. The approach used an Eulerian analysis of liquid flows in the bubble column, and made use of the Lagrangian trajectory analysis for the bubbles and particle motions. The bubble-bubble and particle-particle collisions are included the model. The model predictions are compared with the experimental data and good agreement was found An experimental setup for studying two-dimensional bubble columns was developed. The multiphase flow conditions in the bubble column were measured using optical image processing and Particle Image Velocimetry techniques (PIV). A simple shear flow device for bubble motion in a constant shear flow field was also developed. The flow conditions in simple shear flow device were studied using PIV method. Concentration and velocity of particles of different sizes near a wall in a duct flow was also measured. The technique of Phase-Doppler anemometry was used in these studies. An Eulerian volume of fluid (VOF) computational model for the flow condition in the two-dimensional bubble column was also developed. The liquid and bubble motions were analyzed and the results were compared with observed flow patterns in the experimental setup. Solid-fluid mixture flows in ducts and passages at different angle of orientations were also analyzed. The model predictions were compared with the experimental data and good agreement was found. Gravity chute flows of solid-liquid mixtures were also studied. The simulation results were compared with the experimental data and discussed A thermodynamically consistent model for multiphase slurry flows with and without chemical reaction in a state of turbulent motion was developed. The balance laws were obtained and the constitutive laws established.

  18. Yield Stress Reduction of DWPF Melter Feed Slurries

    SciTech Connect

    Stone, M.E.; Smith, M.E.

    2007-07-01

    , then quenched with a water spray. Approximately 90% of the frit was converted to beads by this process. Yield stress reduction was measured by preparing melter feed slurries (using nonradioactive HLW simulants) that contain beads and comparing the yield stress with melter feed containing frit. A second set of tests was performed with beads of various diameters to determine if a decrease in diameter affected the results. Smaller particle size was shown to increase yield stress when frit is utilized. The settling rate of the beads was required to match the settling rate of the frit, therefore a decrease in particle size was anticipated. Settling tests were conducted in water, xanthan gum solutions, and in non-radioactive simulants of the HLW. The tests used time-lapse video-graphy as well as solids sampling to evaluate the settling characteristics of beads compared to frit of the same particle size. A preliminary melt rate evaluation was performed using a dry-fed Melt Rate Furnace (MRF) developed by SRNL. Preliminary evaluation of the impact of beading the frit on the frit addition system were completed by conducting flow loop testing. A recirculation loop was built with a total length of about 30 feet. Pump power, flow rate, outlet pressure, and observations of the flow in the horizontal upper section of the loop were noted. The recirculation flow was then gradually reduced and the above items recorded until settling was noted in the recirculation line. Overall, the data shows that the line pressure increased as the solids were increased for the same flow rate. In addition, the line pressure was higher for Frit 320 than the beads at the same solids level and flow. With the observations, a determination of minimum velocity to prevent settling could be done, but a graph of the line pressures versus velocity for the various tests was deemed to more objective. The graph shows that the inflection point in pressure drop is about the same for the beads and Frit 320. This

  19. Preliminary investigations on the injection of a coal-oil-slurry into the blast furnace

    NASA Astrophysics Data System (ADS)

    Rejek, U.; Franke, F. H.

    1981-12-01

    The flow and pumping behaviour and sedimentation of coal-oil-slurries as a function of concentration, temperature, coal and oil type, grain size, size distribution, pipe geometry etc. were determined. The results are intended to facilitate the planning of an injection plant and to enable an assessment of the economic feasibility of such a plant. The results show that for trouble-free transportation, (without undue increase in viscosity) the maximum coal concentration is 50 percent by weight with lignite coal-oil-slurries and 65 percent by weight with bituminous low volatile coal-oil-slurries at 80 C. A fine grinding of the coals leads to high viscosity in the slurries. The utilization of coarse particles leads to a rapid sedimentation at low velocities.

  20. Feasibility Studies on Pipeline Disposal of Concentrated Copper Tailings Slurry for Waste Minimization

    NASA Astrophysics Data System (ADS)

    Senapati, Pradipta Kumar; Mishra, Barada Kanta

    2016-06-01

    The conventional lean phase copper tailings slurry disposal systems create pollution all around the disposal area through seepage and flooding of waste slurry water. In order to reduce water consumption and minimize pollution, the pipeline disposal of these waste slurries at high solids concentrations may be considered as a viable option. The paper presents the rheological and pipeline flow characteristics of copper tailings samples in the solids concentration range of 65-72 % by weight. The tailings slurry indicated non-Newtonian behaviour at these solids concentrations and the rheological data were best fitted by Bingham plastic model. The influence of solids concentration on yield stress and plastic viscosity for the copper tailings samples were discussed. Using a high concentration test loop, pipeline experiments were conducted in a 50 mm nominal bore (NB) pipe by varying the pipe flow velocity from 1.5 to 3.5 m/s. A non-Newtonian Bingham plastic pressure drop model predicted the experimental data reasonably well for the concentrated tailings slurry. The pressure drop model was used for higher size pipes and the operating conditions for pipeline disposal of concentrated copper tailings slurry in a 200 mm NB pipe with respect to specific power consumption were discussed.

  1. Sound in a Magnetorheological Slurry

    NASA Astrophysics Data System (ADS)

    Nahmad-Molinari, Y.; Arancibia-Bulnes, C. A.; Ruiz-Suárez, J. C.

    1999-01-01

    We study the propagation of an elastic excitation through a magnetorheological slurry made of hydrogen-reduced iron particles suspended in glycerine. Two different low-frequency longitudinal modes are observed, the second of them appearing as soon as a magnetic field is applied to the fluid. The first mode travels through glycerine channels within the suspension, whereas the second one propagates through the fibrillated structure formed by the iron particles. This second mode is very strong in amplitude and travels at lower speeds, depending on the magnetic field intensity.

  2. Gas holdup in slurry bubble columns: Effect of column diameter and slurry concentrations

    SciTech Connect

    Krishna, R.; Swart, J.W.A. de; Ellenberger, J.; Martina, G.B.; Maretto, C.

    1997-02-01

    In processes for converting natural gas to liquid fuels, bubble-column reactors are finding increasing application. To study the influence of particle concentration on the hydrodynamics of bubble-column slurry reactors operating in the heterogeneous flow regime, experiments were carried out in 0.10, 0.19, and 0.38-m-dia. columns using paraffinic oil as the liquid phase and slurry concentrations of up to 36 vol. %. To interpret experimental results a generalization of the two-phase model for gas-solid fluid beds was used to describe bubble hydrodynamics. The two phases identified are: a dilute phase consisting of fast-rising large bubbles that traverse the column virtually in plug flow and a dense phase that is identified with the liquid phase along with solid particles and entrained small bubbles. The dense phase suffers backmixing considerably. Dynamic gas disengagement was experimented in the heterogeneous flow regime to determine the gas voidage in dilute and dense phases. Experimental data show that increasing the solid concentration decreases the total gas holdup significantly, but the influence on the dilute-phase gas holdup is small. The dense-phase gas voidage significantly decreases gas holdup due to enhanced coalescence of small bubbles resulting from introduction of particles. The dense-phase gas voidage is practically independent of the column diameter. The dilute-phase gas holdup, on the other hand, decreases with increasing column diameter, and this dependence could be described adequately with a slight modification of the correlation of Krishna and Ellenberger developed for gas-liquid systems.

  3. Analysis of barium hydroxide and calcium hydroxide slurry carbonation reactors

    SciTech Connect

    Patch, K.D.; Hart, R.P.; Schumacher, W.A.

    1980-05-01

    The removal of CO/sub 2/ from air was investigated by using a continuous-agitated-slurry carbonation reactor containing either barium hydroxide (Ba(OH)/sub 2/) or calcium hydroxide (Ca(OH)/sub 2/). Such a process would be applied to scrub /sup 14/CO/sub 2/ from stack gases at nuclear-fuel reprocessing plants. Decontamination factors were characterized for reactor conditions which could alter hydrodynamic behavior. An attempt was made to characterize reactor performance with models assuming both plug flow and various degrees of backmixing in the gas phase. The Ba(OH)/sub 2/ slurry enabled increased conversion, but apparently the process was controlled under some conditions by phenomena differing from those observed for carbonation by Ca(OH)/sub 2/. Overall reaction mechanisms are postulated.

  4. Radial arm strike rail

    DOEpatents

    McKeown, Mark H.; Beason, Steven C.

    1991-01-01

    The radial arm strike rail assembly is a system for measurement of bearings, directions, and stereophotography for geologic mapping, particularly where magnetic compasses are not appropriate. The radial arm, pivoting around a shaft axis, provides a reference direction determination for geologic mapping and bearing or direction determination. The centerable and levelable pedestal provide a base for the radial arm strike rail and the telescoping camera pedestal. The telescoping feature of the radial arm strike rail allows positioning the end of the rail for strike direction or bearing measurement with a goniometer.

  5. Optimizing slurry separation in coal preparation

    SciTech Connect

    V.S. Shved; V.H. Fritsler; V.V. Bukhtiyarov

    2009-05-15

    In processing slurry with cationic polyelectrolytes, the final concentration of the suspended particulates in the water beyond the slurry tank in the coal-preparation shop is no more than 10 mg/l. Consequently, this water may be reused in industrial systems.

  6. Plastic Models Designed to Produce Large Height-to-Length Ratio Steady-State Planar and Axisymmetric (Radial) Viscous Liquid Laminar Flow Gravity Currents

    ERIC Educational Resources Information Center

    Blanck, Harvey F.

    2012-01-01

    Naturally occurring gravity currents include events such as air flowing through an open front door, a volcanic eruption's pyroclastic flow down a mountainside, and the spread of the Bhopal disaster's methyl isocyanate gas. Gravity currents typically have a small height-to-distance ratio. Plastic models were designed and constructed with a…

  7. Slurry-pressing consolidation of silicon nitride

    NASA Technical Reports Server (NTRS)

    Sanders, William A.; Kiser, James D.; Freedman, Marc R.

    1989-01-01

    A baseline slurry-pressing method for a silicon nitride material is developed. The Si3N4 composition contained 5.8 wt percent SiO2 and 6.4 wt percent Y2O3. Slurry-pressing variables included volume percent solids, application of ultrasonic energy, and pH. Twenty vol percent slurry-pressed material was approximately 11 percent stronger than both 30 vol percent slurry-pressed and dry-pressed materials. The Student's t-test showed the difference to be significant at the 99 percent confidence level. Twenty volume percent (300 h) slurry-pressed test bars exhibited strengths as high as 980 MPa. Large, columnar beta-Si3N4 grains caused failure in the highest strength specimens. The improved strength correlated with better structural uniformity as determined by radiography, optical microscopy, and image analysis.

  8. Slurry-pressing consolidation of silicon nitride

    NASA Technical Reports Server (NTRS)

    Sanders, William A.; Kiser, James D.; Freedman, Marc R.

    1988-01-01

    A baseline slurry-pressing method for a silicon nitride material is developed. The Si3N4 composition contained 5.8 wt percent SiO2 and 6.4 wt percent Y2O3. Slurry-pressing variables included volume percent solids, application of ultrasonic energy, and pH. Twenty vol percent slurry-pressed material was approximately 11 percent stronger than both 30 vol percent slurry-pressed and dry-pressed materials. The Student's t-test showed the difference to be significant at the 99 percent confidence level. Twenty volume percent (300 h) slurry-pressed test bars exhibited strengths as high as 980 MPa. Large, columnar beta-Si3N4 grains caused failure in the highest strength specimens. The improved strength correlated with better structural uniformity as determined by radiography, optical microscopy, and image analysis.

  9. [Zaidemberg's vascularized radial graft].

    PubMed

    Saint-Cast, Y

    2010-12-01

    In 1991, Carlos Zaidemberg described a new technique to repair scaphoid non-unions with a vascularized bone graft harvested from the radial styloid process. An anatomic study based on 30 dissections after colorized latex injection established the constancy of the radial styloid process's artery, while showing that its origin, course and length were subject to variations. In a retrospective series of 38 cases over a period of 10 years, the vascularized bone graft was indicated for: (1) scaphoid non-union with the presence of avascular changes of the proximal fragment (23 cases); (2) failed prior reconstruction with bone graft and internal fixation (nine cases); (3) degenerative styloid-scaphoid arthritis (three cases); (4) fracture on Preiser dystrophy (three cases). The five steps of the simplified operative technique without dissection of the vascular pedicle include: (1) longitudinal dorso-radial approach, identification of the periosteal portion of the radial styloid process artery; (2) incision of the first and second compartments, longitudinal arthrotomy under the second compartment; (3) styloidectomy and transversal resection of the scaphoid non-union and sclerotic bone; (4) elevation of the vascularized bone graft; (5) transversal and radial insertion of the vascularized bone graft, osteosynthesis by two or three K-wire touching the scaphoid's radial edge. Scaphoid union was obtained in 33 cases out of 38. The only postoperative complications were two transient radial paresthesia. The standardized surgical procedure using vascularized bone graft harvested from the radial styloid process provides an efficient scaphoid reconstruction. PMID:21087882

  10. Triple acting radial seal

    DOEpatents

    Ebert, Todd A; Carella, John A

    2012-03-13

    A triple acting radial seal used as an interstage seal assembly in a gas turbine engine, where the seal assembly includes an interstage seal support extending from a stationary inner shroud of a vane ring, the interstage seal support includes a larger annular radial inward facing groove in which an outer annular floating seal assembly is secured for radial displacement, and the outer annular floating seal assembly includes a smaller annular radial inward facing groove in which an inner annular floating seal assembly is secured also for radial displacement. A compliant seal is secured to the inner annular floating seal assembly. The outer annular floating seal assembly encapsulates the inner annular floating seal assembly which is made from a very low alpha material in order to reduce thermal stress.

  11. Off-Design Performance of Radial-Inflow Turbines

    NASA Technical Reports Server (NTRS)

    Meitner, P. L.; Glassman, A. J.

    1986-01-01

    Computer code determines rotor exit flow from hub to tip. RTOD (Radial Turbine Off-Design), computes off-design performance of radial turbine by modeling flow with stator viscous and trailing-edge losses, and with vaneless space loss between stator and rotor, and with rotor incidence, viscous, clearance, trailing-edge, and disk friction losses.

  12. Roles of additives and surface control in slurry atomization. Final project report

    SciTech Connect

    Tsai, S.C.

    1992-12-31

    This project studies the rheology and airblast atomization of micronized coal slurries. Its major objectives are (1) to promote further understanding of the mechanisms and the roles of additives in airblast atomization of coal water slurry (CWS), and (2) to investigate the impacts of coal particle surface properties and interparticle forces on CWS rheology. We have found that the flow behavior index (n) of a suspension (or slurry) is determined by the relative importance of the interparticle van der Waals attraction and the interparticle electrostatic repulsion. The interparticle attraction, measured by the Hamaker constant scaled to the thermal energy at 25{degrees}C (A/kT), causes particle aggregation, which breaks down at high shear rates, and thus leads to slurry pseudoplastic behavior (n< 1). At a constant particle volume fraction and surface charge density (qualitatively measured by the zeta potential in deionized water), n decreases linearly as A/kT increases. The relative viscosity of the pseudoplastic suspension with respect to that of the suspending liquid is found to be independent of particle density and correlate well with the particle Peclet number which equals the particle diffusional relaxation time multiplied by shear rate. Specifically, the relative viscosities of the pseudoplastic glycerol/water coal slurry and the ethylene glycol/glycerol sand slurry, at same volume fractions as well as similar particle size distributions and liquid viscosities, as functions of the particle Peclet number fall along the same line.

  13. Design considerations for slurry bioreactors

    SciTech Connect

    Zappi, M.E.; Banerji, S.K.; Bajpai, R.K.

    1994-12-31

    Slurry treatment is an innovative approach for bioremediation of contaminated soils under controlled conditions of pH, temperature, and nutrients. This treatment of excavated soils permits better control of environmental conditions than in landfarming, composting, and biocell units, and therefore may achieve accelerated rates of decontamination. Bioslurry reactors have been used to remediate a variety of contaminants, such as soils and sludges from refinery wastes, wood-preserving wastes, wastes containing polychlorinated biphenyls and halogenated solvents. Key considerations in design of such reactors involve meeting the oxygen requirements for biodegradation, preventing the settling of soil particles, efficient mixing of additives, and control of foaming. The aspects of reactor design, specifically agitation system have been discussed in this paper.

  14. Acidification of animal slurry--a review.

    PubMed

    Fangueiro, David; Hjorth, Maibritt; Gioelli, Fabrizio

    2015-02-01

    Ammonia emissions are a major problem associated with animal slurry management, and solutions to overcome this problem are required worldwide by farmers and stakeholders. An obvious way to minimize ammonia emissions from slurry is to decrease slurry pH by addition of acids or other substances. This solution has been used commonly since 2010 in countries such as Denmark, and its efficiency with regard to the minimization of NH3 emissions has been documented in many studies. Nevertheless, the impact of such treatment on other gaseous emissions during storage is not clear, since the studies performed so far have provided different scenarios. Similarly, the impact of the soil application of acidified slurry on plant production and diffuse pollution has been considered in several studies. Also, the impact of acidification upon combination with other slurry treatment technologies (e.g. mechanical separation, anaerobic digestion …) is important to consider. Here, a compilation and critical review of all these studies has been performed in order to fully understand the global impact of slurry acidification and assess the applicability of this treatment for slurry management. PMID:25463570

  15. Method and apparatus for transporting liquid slurries

    DOEpatents

    Berry, Gregory F.; Lyczkowski, Robert W.; Wang, Chi-Sheng

    1993-01-01

    An improved method and device to prevent erosion of slurry transport devices is disclosed which uses liquid injection to prevent contact by the slurry composition with the inner surface of the walls of the transport system. A non-abrasive liquid is injected into the slurry transport system and maintains intimate contact with the entire inner surface of the transport system, thereby creating a fluid barrier between the non-abrasive liquid and the inner surface of the transport system which thereby prevents erosion.

  16. Method and apparatus for transporting liquid slurries

    DOEpatents

    Berry, G.F.; Lyczkowski, R.W.; Chisheng Wang.

    1993-03-16

    An improved method and device to prevent erosion of slurry transport devices is disclosed which uses liquid injection to prevent contact by the slurry composition with the inner surface of the walls of the transport system. A non-abrasive liquid is injected into the slurry transport system and maintains intimate contact with the entire inner surface of the transport system, thereby creating a fluid barrier between the non-abrasive liquid and the inner surface of the transport system which thereby prevents erosion.

  17. FAME Radial Velocity Survey

    NASA Astrophysics Data System (ADS)

    Salim, S.; Gould, A.

    2000-12-01

    Full-Sky Astrometric Mapping Explorer (FAME) belongs to a new generation of astrometry satellites and will probe the surrounding space some 20 times deeper than its predecessor Hipparcos. As a result we will acquire precise knowledge of 5 out of 6 components of phase-space for millions of stars. The remaining coordinate, radial velocity, will remain unknown. In this study, we look at how the knowledge of radial velocity affects the determination of the structure of the Galaxy, and its gravitational potential. We therefore propose a radial velocity survey of FAME stars, and discuss its feasibility and technical requirements.

  18. Methods and apparatus for radially compliant component mounting

    DOEpatents

    Bulman, David Edward; Darkins, Jr., Toby George; Stumpf, James Anthony; Schroder, Mark S.; Lipinski, John Joseph

    2012-03-27

    Methods and apparatus for a mounting assembly for a liner of a gas turbine engine combustor are provided. The combustor includes a combustor liner and a radially outer annular flow sleeve. The mounting assembly includes an inner ring surrounding a radially outer surface of the liner and including a plurality of axially extending fingers. The mounting assembly also includes a radially outer ring coupled to the inner ring through a plurality of spacers that extend radially from a radially outer surface of the inner ring to the outer ring.

  19. Radial nerve dysfunction (image)

    MedlinePlus

    The radial nerve travels down the arm and supplies movement to the triceps muscle at the back of the upper arm. ... the wrist and hand. The usual causes of nerve dysfunction are direct trauma, prolonged pressure on the ...

  20. Radial heat flux transformer

    NASA Technical Reports Server (NTRS)

    Basiulis, A.; Buzzard, R. J.

    1971-01-01

    Unit moves heat radially from small diameter shell to larger diameter shell, or vice versa, with negligible temperature drop, making device useful wherever heating or cooling of concentrically arranged materials, substances, and structures is desired.

  1. Radial nerve dysfunction

    MedlinePlus

    ... may occur: Abnormal sensations to the hand or forearm ("back" of the hand), "thumb side" (radial surface) ... wrist or fingers Muscle loss ( atrophy ) in the forearm Weakness of the wrist and finger Wrist or ...

  2. Radial nerve dysfunction

    MedlinePlus

    ... nerve leads to problems with movement in the arm and wrist and with sensation in the back of the arm or hand. ... to the radial nerve, which travels down the arm and controls movement of the triceps muscle at ...

  3. Radial turbine cooling

    NASA Astrophysics Data System (ADS)

    Roelke, Richard J.

    The technology of high temperature cooled radial turbines is reviewed. Aerodynamic performance considerations are described. Heat transfer and structural analysis are addressed, and in doing so the following topics are covered: cooling considerations, hot side convection, coolant side convection, and rotor mechanical analysis. Cooled rotor concepts and fabrication are described, and the following are covered in this context: internally cooled rotor, hot isostatic pressure bonded rotor, laminated rotor, split blade rotor, and the NASA radial turbine program.

  4. Radial turbine cooling

    NASA Technical Reports Server (NTRS)

    Roelke, Richard J.

    1992-01-01

    The technology of high temperature cooled radial turbines is reviewed. Aerodynamic performance considerations are described. Heat transfer and structural analysis are addressed, and in doing so the following topics are covered: cooling considerations, hot side convection, coolant side convection, and rotor mechanical analysis. Cooled rotor concepts and fabrication are described, and the following are covered in this context: internally cooled rotor, hot isostatic pressure bonded rotor, laminated rotor, split blade rotor, and the NASA radial turbine program.

  5. LIMESTONE SCRUBBER SLURRY AUTOMATIC CONTROL SYSTEMS

    EPA Science Inventory

    The report utilizes current understanding of limestone scrubbers for flue gas desulfurization (FGD) to develop an effort into the optimization of automatic control for the recirculating slurry processes. The acknowledged methods of mathematical modeling, computer simulation, and ...

  6. Recommendations for rheological testing and modelling of DWPF melter feed slurries

    SciTech Connect

    Shadday, M.A. Jr.

    1994-08-01

    The melter feed in the DWPF process is a non-Newtonian slurry. In the melter feed system and the sampling system, this slurry is pumped at a wide range of flow rates through pipes of various diameters. Both laminar and turbulent flows are encountered. Good rheology models of the melter feed slurries are necessary for useful hydraulic models of the melter feed and sampling systems. A concentric cylinder viscometer is presently used to characterize the stress/strain rate behavior of the melter feed slurries, and provide the data for developing rheology models of the fluids. The slurries exhibit yield stresses, and they are therefore modelled as Bingham plastics. The ranges of strain rates covered by the viscometer tests fall far short of the entire laminar flow range, and therefore hydraulic modelling applications of the present rheology models frequently require considerable extrapolation beyond the range of the data base. Since the rheology models are empirical, this cannot be done with confidence in the validity of the results. Axial pressure drop versus flow rate measurements in a straight pipe can easily fill in the rest of the laminar flow range with stress/strain rate data. The two types of viscometer tests would be complementary, with the concentric cylinder viscometer providing accurate data at low strain rates, near the yield point if one exists, and pipe flow tests providing data at high strain rates up to and including the transition to turbulence. With data that covers the laminar flow range, useful rheological models can be developed. In the Bingham plastic model, linear behavior of the shear stress as a function of the strain rate is assumed once the yield stress is exceeded. Both shear thinning and shear thickening behavior have been observed in viscometer tests. Bingham plastic models cannot handle this non-linear behavior, but a slightly more complicated yield/power law model can.

  7. Dewatering fine coal slurries by gel extraction

    SciTech Connect

    Gehrke, S.H.; Lyu, Lii-Hurng.

    1990-01-01

    A new technology called gel extraction has been evaluated to determine its economic viability in dewatering the fine and ultrafine coal slurries generated upon separation of sulfur and ash from clean coal during the physical coal cleaning process. Water must be removed from such slurries prior to transportation and combustion but the dewatering costs are substantial, especially for the fine particles below 28 mesh (0.6 mm). Gel extraction is a potential breakthrough in slurry dewatering technology. The goal of this project was to acquire the qualitative and quantitative data needed to estimate the potential of gel extraction for dewatering coal slurries. The specific objectives were to determine the maximum extents of dewatering (minimum surface moisture in the coal product), the clarity of the water removed (minimum solids content), the speed of the dewatering cycles, the service lifetime of the gels, and the factors which influence all of these. With the results obtained, an economic analysis of Ohio coal cleaning plant dewatering technologies was carried out. The polymer gel at the heart of this project, poly (N-isopropylacrylamide) (PNIPA), can swell several times its shrunken weight at 32[degrees]C by absorbing water at 25[degrees]C. In gel extraction, a shrunken NIPA gel is contacted with a slurry at ambient temperature or cooler; the gel swells by absorbing water from the slurry. The gel is then removed from the dewatered slurry and warmed above its critical temperature of 33[degrees]C, which returns it to the shrunken state by releasing the absorbed water. The facts that the gel is reusable and the process is simple and driven by low-grade energy (warm temperatures), and not inherently limited by particle size, made the process an attractive possible alternative to centrifugation, screening, filtration, etc. for slurry dewatering.

  8. Hall and radial magnetic field effects on radiative peristaltic flow of Carreau-Yasuda fluid in a channel with convective heat and mass transfer

    NASA Astrophysics Data System (ADS)

    Hayat, T.; Farooq, S.; Alsaedi, A.; Ahmad, B.

    2016-08-01

    The purpose of present investigation is to study the Hall and MHD effects on peristaltic flow of Carreau-Yasuda fluid in a convectively curved configuration. Thermal radiation, Soret and Dufour effects are also accounted. The channel walls comprised the no slip and compliant properties. Constitutive equations for mass, momentum, energy and concentration are first modeled in view of considered assumptions and then simplified under long wavelength and low Reynolds number approximation. Solution of the resulting system of equations is carried out via a regular perturbation technique. Physical behaviors of velocity, temperature, concentration and streamlines are discussed with the help of graphical representation.

  9. The rheology of cryovolcanic slurries: Motivation and phenomenology of methanol-water slurries with implications for Titan

    NASA Astrophysics Data System (ADS)

    Zhong, Fang; Mitchell, Karl L.; Hays, Charles C.; Choukroun, Mathieu; Barmatz, Martin; Kargel, Jeffrey S.

    2009-08-01

    The Cassini spacecraft has revealed landforms on the surface of Titan suggested to be viscous cryovolcanic flows and possibly eruptive domes. In order to relate those surface features to the processes and chemistries that produced them, it is necessary to construct flow models, which rely on characterization of the rheological properties of the eruptants. This paper describes our initial exploratory attempts to understand the rheological characteristics of cryogenic slurries, using a 40% methanol-water mixture, as a precursor to more detailed experiments. We have devised a new automated cryogenic rotational viscometer system to more fully characterize cryovolcanic slurry rheologies. A series of measurements were performed, varying first temperature, and then strain rate, which revealed development of yield stress-like behaviors, shear-rate dependence, and thixotropic behavior, even at relatively low crystal fractions, not previously reported. At fixed shear rate our data are fit well by the Andrade equation, with the activation energy modified by a solid volume fraction. At fixed temperature, depending on shearing history, a Cross model could describe our data over a wide shear rate range. A Bingham plastic model appears to be a good constitutive model for the data measured at high shear rates when the shear was global. The yield stress like behavior implies that levee formation on cryolava flows is more likely than would be inferred from the previous studies, and may provide a partial explanation for features interpreted as steep-sided volcanic constructs on Titan.

  10. Runoff- and erosion-driven transport of cattle slurry: linking molecular tracers to hydrological processes

    NASA Astrophysics Data System (ADS)

    Lloyd, C. E. M.; Michaelides, K.; Chadwick, D. R.; Dungait, J. A. J.; Evershed, R. P.

    2016-02-01

    The addition of cattle slurry to agricultural land is a widespread practise, but if not correctly managed it can pose a contamination risk to aquatic ecosystems. The transport of inorganic and organic components of cattle slurry to watercourses is a major concern, yet little is known about the physical transport mechanisms and associated fluxes and timings of contamination threats. Therefore, the aim of the study was to ascertain the importance of flow pathway partitioning in the transport (fluxes and timing) of dissolved and particulate slurry-derived compounds with implications for off-site contamination. A series of rainfall-runoff and erosion experiments were carried out using the TRACE (Test Rig for Advancing Connectivity Experiments) experimental hillslope facility. The experiments allowed the quantification of the impact of changing slope gradient and rainfall intensity on nutrient transport from cattle slurry applied to the hillslope, via surface, subsurface, and vertical percolated flow pathways, as well as particulate transport from erosion. The dissolved components were traced using a combination of ammonium (NH4+) and fluorescence analysis, while the particulate fraction was traced using organic biomarkers, 5β-stanols. Results showed that rainfall events which produced flashy hydrological responses, resulting in large quantities of surface runoff, were likely to move sediment and also flush dissolved components of slurry-derived material from the slope, increasing the contamination risk. Rainfall events which produced slower hydrological responses were dominated by vertical percolated flows removing less sediment-associated material, but produced leachate which could contaminate deeper soil layers, and potentially groundwater, over a more prolonged period. Overall, this research provides new insights into the partitioning of slurry-derived material when applied to an unvegetated slope and the transport mechanisms by which contamination risks are

  11. Runoff- and erosion-driven transport of cattle slurry: linking molecular tracers to hydrological processes

    NASA Astrophysics Data System (ADS)

    Lloyd, C. E. M.; Michaelides, K.; Chadwick, D. R.; Dungait, J. A. J.; Evershed, R. P.

    2015-10-01

    The addition of cattle slurry to agricultural land is a widespread practise, but if not correctly managed it can pose a contamination risk to aquatic ecosystems. The transport of inorganic and organic components of cattle slurry to watercourses is a major concern, yet little is known about the physical transport mechanisms and associated fluxes and timings of contamination threats. Therefore, the aim of the study was to ascertain the importance of flow pathway partitioning in the transport (fluxes and timing) of dissolved and particulate slurry-derived compounds with implications for off-site contamination. A series of rainfall-runoff and erosion experiments were carried out using the TRACE (Test Rig for Advancing Connectivity Experiments) experimental hillslope facility. The experiments allowed the quantification of the impact of changing slope gradient and rainfall intensity on nutrient transport from cattle slurry applied to the hillslope, via surface, subsurface and vertical percolated flow pathways, as well as particulate transport from erosion. The dissolved components were traced using a combination of ammonium (NH4+) and fluorescence analysis, while the particulate fraction was traced using organic biomarkers, 5β-stanols. Results showed that rainfall events which produced flashy hydrological responses, resulting in large quantities of surface runoff, were likely to move sediment and also flush dissolved components of slurry-derived material from the slope, increasing the contamination risk. Rainfall events which produced slower hydrological responses were dominated by vertical percolated flows removing less sediment-associated material, but produced leachate which could contaminate deeper soil layers, and potentially groundwater, over a more prolonged period. Overall, this research provides new insights into the partitioning of slurry-derived material when applied to an unvegetated slope and the transport mechanisms by which contamination risks are created.

  12. [Approaches to radial shaft].

    PubMed

    Bartoníček, J; Naňka, O; Tuček, M

    2015-10-01

    In the clinical practice, radial shaft may be exposed via two approaches, namely the posterolateral Thompson and volar (anterior) Henry approaches. A feared complication of both of them is the injury to the deep branch of the radial nerve. No consensus has been reached, yet, as to which of the two approaches is more beneficial for the proximal half of radius. According to our anatomical studies and clinical experience, Thompson approach is safe only in fractures of the middle and distal thirds of the radial shaft, but highly risky in fractures of its proximal third. Henry approach may be used in any fracture of the radial shaft and provides a safe exposure of the entire lateral and anterior surfaces of the radius.The Henry approach has three phases. In the first phase, incision is made along the line connecting the biceps brachii tendon and the styloid process of radius. Care must be taken not to damage the lateral cutaneous nerve of forearm.In the second phase, fascia is incised and the brachioradialis identified by the typical transition from the muscle belly to tendon and the shape of the tendon. On the lateral side, the brachioradialis lines the space with the radial artery and veins and the superficial branch of the radial nerve running at its bottom. On the medial side, the space is defined by the pronator teres in the proximal part and the flexor carpi radialis in the distal part. The superficial branch of the radial nerve is retracted together with the brachioradialis laterally, and the radial artery medially.In the third phase, the attachment of the pronator teres is identified by its typical tendon in the middle of convexity of the lateral surface of the radial shaft. The proximal half of the radius must be exposed very carefully in order not to damage the deep branch of the radial nerve. Dissection starts at the insertion of the pronator teres and proceeds proximally along its lateral border in interval between this muscle and insertion of the supinator

  13. Radial turbine cooling

    NASA Technical Reports Server (NTRS)

    Roelke, Richard J.

    1992-01-01

    Radial turbines have been used extensively in many applications including small ground based electrical power generators, automotive engine turbochargers and aircraft auxiliary power units. In all of these applications the turbine inlet temperature is limited to a value commensurate with the material strength limitations and life requirements of uncooled metal rotors. To take advantage of all the benefits that higher temperatures offer, such as increased turbine specific power output or higher cycle thermal efficiency, requires improved high temperature materials and/or blade cooling. Extensive research is on-going to advance the material properties of high temperature superalloys as well as composite materials including ceramics. The use of ceramics with their high temperature potential and low cost is particularly appealing for radial turbines. However until these programs reach fruition the only way to make significant step increases beyond the present material temperature barriers is to cool the radial blading.

  14. Radial Nerve Tendon Transfers.

    PubMed

    Cheah, Andre Eu-Jin; Etcheson, Jennifer; Yao, Jeffrey

    2016-08-01

    Radial nerve palsy typically occurs as a result of trauma or iatrogenic injury and leads to the loss of wrist extension, finger extension, thumb extension, and a reduction in grip strength. In the absence of nerve recovery, reconstruction of motor function involves tendon transfer surgery. The most common donor tendons include the pronator teres, wrist flexors, and finger flexors. The type of tendon transfer is classified based on the donor for the extensor digitorum communis. Good outcomes have been reported for most methods of radial nerve tendon transfers as is typical for positional tendon transfers not requiring significant power. PMID:27387076

  15. Radially uniform electron source

    NASA Technical Reports Server (NTRS)

    Mccomas, D.; Bame, S. J.

    1982-01-01

    A thermionic electron source capable of producing uniform count rates in a number of channel electron multipliers simultaneously was required for conditioning multipliers for an extended space mission. It was found that a straight tungsten filament in the center of a cylindrically symmetric geometry surrounded by an array of multipliers emits a radially asymmetric distribution of electrons that changes with time. A source was developed which successfully produces a time-independent radially uniform distribution of electrons by moving the filament out of the direct line of sight and replacing it with a centrally located electron 'cloud.'

  16. Radial wedge flange clamp

    DOEpatents

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  17. A novel method of atomizing coal-water slurry fuels

    SciTech Connect

    Sojka, P.E.; Lefebvre, A.H.

    1990-05-01

    Despite the body of work describing the performance of effervescent atomizers, its potential for use with coal water slurries (CWS) had not been evaluated prior to this study. This program was therefore undertaken: to demonstrate that effervescent atomization can produce CWS sprays with mean drop sizes below 50{mu}m; to determine a lower size limit for effervescent atomizer produced CWS sprays; to determine the mechanism(s) responsible for the formation of effervescent atomizer produced sprays. An analysis of the effects of slurry rheological properties (as indicated by the consistency index and the flow behavior index) and formulation (in terms of loading and coal particle top size) on the spray formation process was performed. The experimental data reported were then analyzed to explain the physical processes responsible for spray formation. The analysis began by considering an energy balance across a control volume that extended from the nozzle exit plant to the line of spray measurement. The inlet conditions were calculated using two-phase flow techniques and the outlet conditions were calculated by using conservation of momentum and assuming that the final velocities of the air and liquid were equal. Entrainment was considered negligible and losses were accounted for by realizing that only a small fraction of the atomizing air participated in the spray formation process with the remainder passing through the control volume unperturbed. Results are discussed. 41 figs., 4 tabs.

  18. Characterization and Delivery of Hanford High-Level Radioactive Waste Slurry

    SciTech Connect

    Thien, Michael G.; Denslow, Kayte M.; Lee, K. P.

    2014-11-15

    Two primary challenges to characterizing Hanford’s high-level radioactive waste slurry prior to transfer to a treatment facility are the ability to representatively sample million-gallon tanks and to estimate the critical velocity of the complex slurry. Washington River Protection Solutions has successfully demonstrated a sampling concept that minimizes sample errors by collecting multiple sample increments from a sample loop where the mixed tank contents are recirculated. Pacific Northwest National Laboratory has developed and demonstrated an ultrasonic-based Pulse-Echo detection device that is capable of detecting a stationary settled bed of solids in a pipe with flowing slurry. These two concepts are essential elements of a feed delivery strategy that drives the Hanford clean-up mission.

  19. Combustion behavior of single coal-water slurry droplets, Part 1: Experimental techniques

    SciTech Connect

    Levendis, Y.A.; Metghalchi, M.; Wise, D.

    1991-12-31

    Techniques to produce single droplets of coal-water slurries have been developed in order to study the combustion behavior of the slurries. All stages of slurry combustion are of interest to the present study, however, emphasis will be given to the combustion of the solid agglomerate char which remains upon the termination of the water evaporation and the devolatilization periods. An experimental facility is under construction where combustion of coal-water slurries will be monitored in a variety of furnace temperatures and oxidizing atmospheres. The effect of the initial size of the slurry droplet and the solids loading (coal to water ratio) will be investigated. A drop tube, laminar flow furnace coupled to a near-infrared, ratio pyrometer win be used to monitor temperature-time histories of single particles from ignition to extinction. This paper describes the experimental built-up to this date and presents results obtained by numerical analysis that help understanding the convective and radiating environment in the furnace.

  20. Hydraulic properties of Hanford Waste Vitrification Project 39-4 frit slurries

    SciTech Connect

    Abrigo, G.P.

    1996-03-01

    Pacific Northwest Laboratory (PNL) conducted this study for Fluor Daniel Inc. and Westinghouse Hanford Company. The purpose of the study was to assess the effect of solids loading on the hydraulic properties of frit slurries. The effect of solids loading on the hydraulic properties of the fret slurries was evaluated by testing various concentrations of frit slurries in various sized schedule 40 stainless steel piping. The pressure drop in straight and 90-degree long radius elbow sections was measured as a function of flowrate, pipe size, and solids concentration. The results of testing yielded recommendations for predicting the pressure drop as a function of solids concentration, pipe size, and flow-rate. The contribution of a 90-degree long radius elbow to the pressure drop was measured and recommendations given. Observations were also made on solids settling in the lines, wear on the testing equipment, slurry properties, and measuring equipment performance. The equipment and procedures used for pumping the high solids concentration frit slurry were successful in completing the test.

  1. An investigation on characterizing dense coal-water slurry with ultrasound: theoretical and experimental method

    SciTech Connect

    Xue, M.H.; Su, M.X.; Dong, L.L.; Shang, Z.T.; Cai, X.S.

    2010-07-01

    Particle size distribution and concentration in particulate two-phase flow are important parameters in a wide variety of industrial areas. For the purpose of online characterization in dense coal-water slurries, ultrasonic methods have many advantages such as avoiding dilution, the capability for being used in real time, and noninvasive testing, while light-based techniques are not capable of providing information because optical methods often require the slurry to be diluted. In this article, the modified Urick equation including temperature modification, which can be used to determine the concentration by means of the measurement of ultrasonic velocity in a coal-water slurry, is evaluated on the basis of theoretical analysis and experimental study. A combination of the coupled-phase model and the Bouguer-Lambert-Beer law is employed in this work, and the attenuation spectrum is measured within the frequency region from 3 to 12 MHz. Particle size distributions of the coal-water slurry at different volume fractions are obtained with the optimum regularization technique. Therefore, the ultrasonic technique presented in this work brings the possibility of using ultrasound for online measurements of dense slurries.

  2. Rheological properties of defense waste slurries

    SciTech Connect

    Ebadian, M.A.

    1998-01-01

    The major objective of this two-year project has been to obtain refined and reliable experimental data about the rheological properties of melter feeds. The research has involved both experimental studies and model development. Two experimental facilities have been set up to measure viscosity and pressure drop. Mathematical models have been developed as a result of experimental observation and fundamental rheological theory. The model has the capability to predict the viscosity of melter slurries in a range of experimental conditions. The final results of the investigation could be used to enhance the current design base for slurry transportation systems and improve the performance of the slurry mixing process. If successful, the cost of this waste treatment will be reduced, and disposal safety will be increased. The specific objectives for this project included: (1) the design, implementation, and validation of the experimental facility in both batch and continuous operating modes; (2) the identification and preparation of melter feed samples of both the SRS and Hanford waste slurries at multiple solids concentration levels; (3) the measurement and analysis of the melter feeds to determine the effects of the solids concentration, pH value, and other factors on the rheological properties of the slurries; (4) the correlation of the rheological properties as a function of the measured physical and chemical parameters; and (5) transmission of the experimental data and resulting correlation to the DOE site user to guide melter feed preparation and transport equipment design.

  3. Radial forces in a misaligned radial face seal

    NASA Technical Reports Server (NTRS)

    Etsion, I.

    1977-01-01

    Radial forces on the primary seal ring of a flat misaligned seal are analyzed, taking into account the radial variation in seal clearance. An analytical solution for both hydrostatic and hydrodynamic effects is presented that covers the whole range from zero to full angular misalignment. The net radial force on the primary seal ring is always directed so as to produce a radial eccentricity which generates inward pumping. Although the radial force is usually very small, in some cases it may be one of the reasons for excessive leakage through both the primary and secondary seals of a radial face seal.

  4. Radial forces in a misaligned radial face seal

    NASA Technical Reports Server (NTRS)

    Etsion, I.

    1978-01-01

    Radial forces on the primary seal ring of a flat misaligned seal are analyzed, taking into account the radial variation in seal clearance. An analytical solution for both hydrostatic and hydrodynamic effects is presented that covers the whole range from zero to full angular misalignment. The net radial force on the primary seal ring is always directed so as to produce a radial eccentricity which generates inward pumping. Although the radial force is usually very small, in some cases it may be one of the reasons for excessive leakage through both the primary and secondary seals of a radial face seal.

  5. Lightweight Cement Slurries based on vermiculite

    NASA Astrophysics Data System (ADS)

    Minaev, K.; Gorbenko, V.; Ulyanova, O.

    2014-08-01

    The main purpose of the research is to study the lightweight cement slurry based on vermiculite and its parameters in accordance with GOST 1581-96 requirements as well as improvement of its formulation by polymer additives. Analysis of vermiculite-containing mixture providing the lowest density while maintaining other required parameters was conducted. As a cement base, cement PTscT-I-G-CC-1, cement PTscT - 100 and vermiculite M200 and M150 were used. Vermiculite content varied from 10 to 15 %; and water-to-cement-ratio ranged from 0.65 to 0.8. To sum up, despite the fact that lightweight cement slurry based on vermiculite satisfies GOST 1581-96 requirements under laboratory conditions, field studies are necessary in order to make a conclusion about applicability of this slurry for well cementing.

  6. Effect of Particle Size Distribution on Slurry Rheology: Nuclear Waste Simulant Slurries

    SciTech Connect

    Chun, Jaehun; Oh, Takkeun; Luna, Maria L.; Schweiger, Michael J.

    2011-07-05

    Controlling the rheological properties of slurries has been of great interest in various industries such as cosmetics, ceramic processing, and nuclear waste treatment. Many physicochemical parameters, such as particle size, pH, ionic strength, and mass/volume fraction of particles, can influence the rheological properties of slurry. Among such parameters, the particle size distribution of slurry would be especially important for nuclear waste treatment because most nuclear waste slurries show a broad particle size distribution. We studied the rheological properties of several different low activity waste nuclear simulant slurries having different particle size distributions under high salt and high pH conditions. Using rheological and particle size analysis, it was found that the percentage of colloid-sized particles in slurry appears to be a key factor for rheological characteristics and the efficiency of rheological modifiers. This behavior was shown to be coupled with an existing electrostatic interaction between particles under a low salt concentration. Our study suggests that one may need to implement the particle size distribution as a critical factor to understand and control rheological properties in nuclear waste treatment plants, such as the U.S. Department of Energy’s Hanford and Savannah River sites, because the particle size distributions significantly vary over different types of nuclear waste slurries.

  7. CFD simulation and experimental analysis of erosion in a slurry tank test rig

    NASA Astrophysics Data System (ADS)

    Azimian, Mehdi; Bart, Hans-Jörg

    2013-04-01

    Erosion occurring in equipment dealing with liquid-solid mixtures such as pipeline parts, slurry pumps, liquid-solid stirred reactors and slurry mixers in various industrial applications results in operational failure and economic costs. A slurry erosion tank test rig is designed and was built to investigate the erosion rates of materials and the influencing parameters such as flow velocity and turbulence, flow angle, solid particle concentration, particles size distribution, hardness and target material properties on the material loss and erosion profiles. In the present study, a computational fluid dynamics (CFD) tool is used to simulate the erosion rate of sample plates in the liquid-solid slurry mixture in a cylindrical tank. The predictions were made in a steady state and also transient manner, applying the flow at the room temperature and using water and sand as liquid and solid phases, respectively. The multiple reference frame method (MRF) is applied to simulate the flow behavior and liquid-solid interactions in the slurry tank test rig. The MRF method is used since it is less demanding than sliding mesh method (SM) and gives satisfactory results. The computational domain is divided into three regions: a rotational or MRF zone containing the mixer, a rotational zone (MRF) containing the erosion plates and a static zone (outer liquid zone). It is observed that changing the MRF zone diameter and height causes a very low impact on the results. The simulated results were obtained for two kinds of hard metals namely stainless steel and ST-50 under some various operating conditions and are found in good agreement with the experimental results.

  8. Radial Halbach Magnetic Bearings

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2009-01-01

    Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Radial Halbach magnetic bearings are based on the same principle as that of axial Halbach magnetic bearings, differing in geometry as the names of these two types of bearings suggest. Both radial and axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control. Axial Halbach magnetic bearings were described in Axial Halbach Magnetic Bearings (LEW-18066-1), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), page 85. In the remainder of this article, the description of the principle of operation from the cited prior article is recapitulated and updated to incorporate the present radial geometry. In simplest terms, the basic principle of levitation in an axial or radial Halbach magnetic bearing is that of the repulsive electromagnetic force between (1) a moving permanent magnet and (2) an electric current induced in a stationary electrical conductor by the motion of the magnetic field. An axial or radial Halbach bearing includes multiple permanent magnets arranged in a Halbach array ("Halbach array" is defined below) in a rotor and multiple conductors in the form of wire coils in a stator, all arranged so the rotary motion produces an axial or radial repulsion that is sufficient to levitate the rotor. A basic Halbach array (see Figure 1) consists of a row of permanent magnets, each oriented so that its magnetic field is at a right angle to that of the adjacent magnet, and the right-angle turns are sequenced so as to maximize the magnitude of the magnetic flux density on one side of the row while

  9. SUCCESSES AND EMERGING ISSUES IN SIMULATING THE PROCESSING BEHAVIOR OF LIQUID-PARTICLE NUCLEAR WASTE SLURRIES AT THE SAVANNAH RIVER SITE - 205E

    SciTech Connect

    Koopman, D.; Lambert, D.; Stone, M.

    2009-09-02

    Slurries of inorganic solids, containing both stable and radioactive elements, were produced during the cold war as by-products of the production of plutonium and enriched uranium and stored in large tanks at the Savannah River Site. Some of this high level waste is being processed into a stable glass waste form today. Waste processing involves various large scale operations such as tank mixing, inter-tank transfers, washing, gravity settling and decanting, chemical adjustment, and vitrification. The rheological properties of waste slurries are of particular interest. Methods for modeling flow curve data and predicting the properties of slurry blends are particularly important during certain operational phases. Several methods have been evaluated to predict the rheological properties of sludge slurry blends from the data on the individual slurries. These have been relatively successful.

  10. Prospects for coal slurry pipelines in California

    NASA Technical Reports Server (NTRS)

    Lynch, J. F.

    1978-01-01

    The coal slurry pipeline segment of the transport industry is emerging in the United States. If accepted it will play a vital role in meeting America's urgent energy requirements without public subsidy, tax relief, or federal grants. It is proven technology, ideally suited for transport of an abundant energy resource over thousands of miles to energy short industrial centers and at more than competitive costs. Briefly discussed are the following: (1) history of pipelines; (2) California market potential; (3) slurry technology; (4) environmental benefits; (5) market competition; and (6) a proposed pipeline.

  11. Lithium batteries with organic slurry cathodes

    SciTech Connect

    Bruder, A.H.

    1986-04-01

    This patent describes a laminar electrical cell. This cell consists of a sheet of conductive plastic, a separator, a cathode consisting essentially of a slurry of dewatered MnO/sub 2/ and carbon particles in a solution of a lithium salt in a substantially anhydrous organic solvent between and in contact with the conductive plastic sheet and the separator with the solution permeating the separator. The slurry is free of any binder material, and a thin sheet of lithium is in contact with the separator. The separator being interposed between the cathode and the lithium sheet.

  12. Air blast type coal slurry fuel injector

    DOEpatents

    Phatak, Ramkrishna G.

    1986-01-01

    A device to atomize and inject a coal slurry in the combustion chamber of an internal combustion engine, and which eliminates the use of a conventional fuel injection pump/nozzle. The injector involves the use of compressed air to atomize and inject the coal slurry and like fuels. In one embodiment, the breaking and atomization of the fuel is achieved with the help of perforated discs and compressed air. In another embodiment, a cone shaped aspirator is used to achieve the breaking and atomization of the fuel. The compressed air protects critical bearing areas of the injector.

  13. Air blast type coal slurry fuel injector

    DOEpatents

    Phatak, R.G.

    1984-08-31

    A device to atomize and inject a coal slurry in the combustion chamber of an internal combustion engine is disclosed which eliminates the use of a conventional fuel injection pump/nozzle. The injector involves the use of compressed air to atomize and inject the coal slurry and like fuels. In one embodiment, the breaking and atomization of the fuel is achieved with the help of perforated discs and compressed air. In another embodiment, a cone shaped aspirator is used to achieve the breaking and atomization of the fuel. The compressed air protects critical bearing areas of the injector.

  14. Circulation in gas-slurry column reactors

    SciTech Connect

    Clark, N.; Kuhlman, J.; Celik, I.; Gross, R.; Nebiolo, E.; Wang, Yi-Zun.

    1990-08-15

    Circulation in bubble columns, such as those used in fischer-tropsch synthesis, detracts from their performance in that gas is carried on average more rapidly through the column, and the residence time distribution of the gas in the column is widened. Both of these factors influence mass-transfer operations in bubble columns. Circulation prediction and measurement has been undertaken using probes, one-dimensional models, laser Doppler velocimetry, and numerical modeling. Local void fraction was measured using resistance probes and a newly developed approach to determining air/water threshold voltage for the probe. A tall column of eight inch diameter was constructed of Plexiglas and the distributor plate was manufactured to distribute air evenly through the base of the column. Data were gathered throughout the volume at three different gas throughputs. Bubble velocities proved difficult to measure using twin probes with cross-correlation because of radial bubble movement. A series of three-dimensional mean and RMS bubble and liquid velocity measurements were also obtained for a turbulent flow in a laboratory model of a bubble column. These measurements have been made using a three-component laser Doppler velocimeter (LDV), to determine velocity distributions non-intrusively. Finally, the gas-liquid flow inside a vertically situated circular isothermal column reactor was simulated numerically. 74 refs., 170 figs., 5 tabs.

  15. On magnetopause inflation under radial IMF

    NASA Astrophysics Data System (ADS)

    Suvorova, A. V.; Dmitriev, A. V.

    2016-07-01

    Full understanding of the magnetosphere interaction with radial IMF structures embedded in the solar wind flow is far from completeness. In order to analyze the effects of radial IMF, we use THEMIS observations of the magnetopause and magnetosheath together with upstream data acquired from ACE and Wind monitors as well as from the OMNI data base. We demonstrate a prominent magnetopause inflation and low pressure magnetosheath (LPM) mode under long-lasting radial IMF. We propose that these phenomena result from a kinetic effect of energetic ions taking the energy away from the pressure balance at the magnetopause. We show that strict quantitative determination of the inflation and LPM mode as a function of the cone angle is difficult because of the problems with reliable determination of the upstream and magnetosheath conditions. The shortcomings are caused by such effects as ambiguous time delay for the solar wind propagation, THEMIS orbital bias and model-dependent estimations of the magnetopause inflation.

  16. Radial inflow gas turbine engine with advanced transition duct

    SciTech Connect

    Wiebe, David J

    2015-03-17

    A gas turbine engine (10), including: a turbine having radial inflow impellor blades (38); and an array of advanced transition combustor assemblies arranged circumferentially about the radial inflow impellor blades (38) and having inner surfaces (34) that are adjacent to combustion gases (40). The inner surfaces (34) of the array are configured to accelerate and orient, for delivery directly onto the radial inflow impellor blades (38), a plurality of discrete flows of the combustion gases (40). The array inner surfaces (34) define respective combustion gas flow axes (20). Each combustion gas flow axis (20) is straight from a point of ignition until no longer bound by the array inner surfaces (34), and each combustion gas flow axis (20) intersects a unique location on a circumference defined by a sweep of the radial inflow impellor blades (38).

  17. Effect of radial flow on two particle correlations with identified triggers at intermediate pT in p-Pb collisions at √{sNN} = 5.02 TeV

    NASA Astrophysics Data System (ADS)

    Sarkar, Debojit; Choudhury, Subikash; Chattopadhyay, Subhasis

    2016-09-01

    Results from two-particle correlation between identified triggers (pions (π±), protons (p / p bar)) and un-identified charged particles at intermediate transverse momentum (pT) in p-Pb collisions at √{sNN} = 5.02 TeV have been presented. The events generated from a hybrid Monte-Carlo event generator, EPOS 3.107 that implements a flux-tube initial conditions followed by event by event 3+1D viscous hydrodynamical evolution, have been analyzed to calculate two-dimensional correlation functions in Δη- Δϕ. The strength of angular correlations at small relative angles (jet-like correlations), quantified in terms of near-side jet-like per-trigger yield has been calculated as a function of the event multiplicity. The yield associated with pion triggers exhibit negligible multiplicity dependence, while the proton-triggered yield shows a gradual suppression from low to high multiplicity events. In small collision systems like p-Pb where jet modification is expected to be less dominant, the observed suppression may be associated with the hydrodynamical evolution of the bulk system that generates an outward radial flow. Analogous measurements in Au-Au collisions at RHIC energy have shown a hint of dilution in proton-triggered correlation at its highest multiplicity suggesting that the soft physics processes in p-Pb and heavy ion collisions may have qualitative similarity.

  18. Variable stator radial turbine

    NASA Technical Reports Server (NTRS)

    Rogo, C.; Hajek, T.; Chen, A. G.

    1984-01-01

    A radial turbine stage with a variable area nozzle was investigated. A high work capacity turbine design with a known high performance base was modified to accept a fixed vane stagger angle moveable sidewall nozzle. The nozzle area was varied by moving the forward and rearward sidewalls. Diffusing and accelerating rotor inlet ramps were evaluated in combinations with hub and shroud rotor exit rings. Performance of contoured sidewalls and the location of the sidewall split line with respect to the rotor inlet was compared to the baseline. Performance and rotor exit survey data are presented for 31 different geometries. Detail survey data at the nozzle exit are given in contour plot format for five configurations. A data base is provided for a variable geometry concept that is a viable alternative to the more common pivoted vane variable geometry radial turbine.

  19. Radial pressure flange seal

    DOEpatents

    Batzer, T.H.; Call, W.R.

    1989-01-24

    This invention provides an all metal seal for vacuum or pressure vessels or systems. This invention does not use gaskets. The invention uses a flange which fits into a matching groove. Fluid pressure is applied in a chamber in the flange causing at least one of the flange walls to radially press against a side of the groove creating the seal between the flange wall and the groove side. 5 figs.

  20. Radial pressure flange seal

    DOEpatents

    Batzer, Thomas H.; Call, Wayne R.

    1989-01-01

    This invention provides an all metal seal for vacuum or pressure vessels or systems. This invention does not use gaskets. The invention uses a flange which fits into a matching groove. Fluid pressure is applied in a chamber in the flange causing at least one of the flange walls to radially press against a side of the groove creating the seal between the flange wall and the groove side.

  1. Development of a phenomenological model for coal slurry atomization

    SciTech Connect

    Dooher, J.P.

    1995-11-01

    Highly concentrated suspensions of coal particles in water or alternate fluids appear to have a wide range of applications for energy production. For enhanced implementation of coal slurry fuel technology, an understanding of coal slurry atomization as a function coal and slurry properties for specific mechanical configurations of nozzle atomizers should be developed.

  2. CATALYTIC RECOMBINATION OF RADIOLYTIC GASES IN THORIUM OXIDE SLURRIES

    DOEpatents

    Morse, L.E.

    1962-08-01

    A method for the coinbination of hydrogen and oxygen in aqueous thorium oxide-uranium oxide slurries is described. A small amount of molybdenum oxide catalyst is provided in the slurry. This catalyst is applicable to the recombination of hydrogen and/or deuterium and oxygen produced by irradiation of the slurries in nuclear reactors. (AEC)

  3. SEPARATING LIQUID MODERATOR FROM A SLURRY TYPE REACTOR

    DOEpatents

    Vernon, H.C.

    1961-07-01

    A system for evaporating moderator such as D/sub 2/O from an irradiated slurry or sloution characterized by two successive evaproators is described. In the first of these the most troublesome radioactivity dissipates before the slurry becomes too thick to be pumped out; in the second the slurry, now easier to handle, can be safely reduced to a sludge.

  4. Radially inhomogeneous bounded plasmas

    NASA Astrophysics Data System (ADS)

    Zakeri-Khatir, H.; Aghamir, F. M.

    2016-07-01

    On the basis of kinetic theory along with self-consistent field equations, the expressions for dielectric tensor of radially inhomogeneous magnetized plasma columns are obtained. The study of dielectric tensor characteristics allows the accurate analysis of the inhomogeneous properties, beyond limitations that exist in the conventional method. Through the Bessel–Fourier transformation, the localized form of material equations in a radially inhomogeneous medium are obtained. In order to verify the integrity of the model and reveal the effect of inhomogeneity, a special case of a cylindrical plasma waveguide completely filled with inhomogeneous magnetized cold plasma was considered. The dispersion relation curves for four families of electromagnetic (EH and HE) and electrostatic (SC and C) modes are obtained and compared with the findings of the conventional model. The numerical analysis indicates that the inhomogeneity effect leads to coupling of electromagnetic and electrostatic modes each having different radial eigen numbers. The study also reveals that the electrostatic modes are more sensitive to inhomogeneous effects than the electromagnetic modes.

  5. Radial Field Piezoelectric Diaphragms

    NASA Technical Reports Server (NTRS)

    Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.

    2002-01-01

    A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.

  6. Freeforming objects with low-binder slurry

    SciTech Connect

    Cesarano, J. III; Calvert, P.D.

    2000-02-22

    In a rapid prototyping system, a part is formed by depositing a bead of slurry that has a sufficient high concentration of particles to be pseudoplastic and almost no organic binders. After deposition the bead is heated to drive off sufficient liquid to cause the bead to become dilatant.

  7. SLURRY TRENCH CONSTRUCTION FOR POLLUTION MIGRATION CONTROL

    EPA Science Inventory

    The handbook provides in-depth guidance on the use of slurry walls for the control of subsurface pollutants. It describes how these barriers can be employed for waste site remediation and presents the theory of their function and use. The handbook describes the essential elements...

  8. Freeforming objects with low-binder slurry

    DOEpatents

    Cesarano, III, Joseph; Calvert, Paul D.

    2000-01-01

    In a rapid prototyping system, a part is formed by depositing a bead of slurry that has a sufficient high concentration of particles to be pseudoplastic and almost no organic binders. After deposition the bead is heated to drive off sufficient liquid to cause the bead to become dilatant.

  9. Survival of Rhizobium inoculum in hydroseeding slurries

    SciTech Connect

    Brown, M.B.; Wolf, D.D.; Morse, R.D.; Neal, J.L.

    1982-12-01

    Disturbed lands such as surface mined areas generally require fertilizer, lime, mulch, and seed for revegetation. Hydroseeding is the most widely used seeding method for mountainous terrain. Where legumes are included in the mixture, Rhizobium inoculum is recommended since disturbed areas are likely to lack indigenous rhizobia. The pH and viability of rhizobia cells in hydroseeder mix slurries were determined in order to establish recommendations for hydroseeding conditions. Of the fertilizer components commonly used for hydroseeding only those containing phosphorus influenced slurry pH. Varying concentrations of triple superphosphate (TSP) and diammonium phosphate (DAP) resulted in hydroseeder mixture pH values ranging from 2.9 to 7.7, respectively. Significant loss of viability of rhizobia occurred at pH values of less than 6.0. In practice, a hydroseeding slurry should contain enough DAP in the fertilizer blend to have a pH of 6.0 or greater which is equivalent to a ratio of DAP to TSP of 4 to 6. Thus, at least 40 of each 100 kg of phosphate should be supplied by DAP. Pulverized agriculture lime did not correct slurry acidity; however, hydrated lime (calcium hydroxide) if added in sufficient amounts could be used to increase the pH to a level that does not significantly alter the viability of the rhizobia.

  10. Coal slurry combustion and technology. Volume 2

    SciTech Connect

    Not Available

    1983-01-01

    Volume II contains papers presented at the following sessions of the Coal Slurry Combustion and Technology Symposium: (1) bench-scale testing; (2) pilot testing; (3) combustion; and (4) rheology and characterization. Thirty-three papers have been processed for inclusion in the Energy Data Base. (ATT)

  11. Low Cost Dewatering of Waste Slurries

    NASA Technical Reports Server (NTRS)

    Peterson, J. B.; Sharma, S. K.; Church, R. H.; Scheiner, B. J.

    1993-01-01

    The U.S. Bureau of Mines has developed a technique for dewatering mineral waste slurries which utilizes polymer and a static screen. A variety of waste slurries from placer gold mines and crushed stone operations have been successfully treated using the system. Depending on the waste, a number of polymers have been used successfully with polymer costs ranging from $0.05 to $0.15 per 1,000 gal treated. The dewatering is accomplished using screens made from either ordinary window screen or wedge wire. The screens used are 8 ft wide and 8 ft long. The capacity of the screens varies from 3 to 7 gpm/sq. ft. The water produced is acceptable for recycling to the plant or for discharge to the environment. For example, a fine grain dolomite waste slurry produced from a crushed stone operation was dewatered from a nominal 2.5 pct solids to greater than 50 pct solids using $0.10 to $0.15 worth of polymer per 1,000 gal of slurry. The resulting waste water had a turbidity of less than 50 NTU and could be discharged or recycled. The paper describes field tests conducted using the polymer-screen dewatering system.

  12. Aerated atomization of coal water slurry

    SciTech Connect

    Buckner, H.N.; Sojka, P.E.; Lefebvre, A.H.

    1989-01-05

    In order to better understand the process of slurry atomization, it is important to observe the influence of fluid non-Newtonian rheological behavior on the spray formation process. As a first step, glycerin-water solutions have been atomized. This report describes findings of photographs taken during atomization. 19 figs.

  13. Antiproton compression and radial measurements

    SciTech Connect

    Andresen, G. B.; Bowe, P. D.; Hangst, J. S.; Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Jenkins, M. J.; Joergensen, L. V.; Madsen, N.; Werf, D. P. van der; Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A.; Wurtele, J. S.; Cesar, C. L.; Lambo, R.; Silveira, D. M.; Fujiwara, M. C.

    2008-08-08

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, achieved by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile, and its relation to that of the electron plasma. We also measure the outer radial profile by ejecting antiprotons to the trap wall using an octupole magnet.

  14. Correlations to predict frictional pressure loss of hydraulic-fracturing slurry in coiled tubing

    SciTech Connect

    Shah, S.; Zhoi, Y.X.; Bailey, M.; Hernandez, J.

    2009-08-15

    Compared with conventional-tubing fracturing, coiled-tubing (CT) fracturing has several advantages. CT fracturing has become an effective stimulation technique for multizone oil and gas wells. It is also an attractive production-enhancement method for multiseam coalbed-methane wells, and wells with bypassed zones. The excessive frictional pressure loss through CT has been a concern in fracturing. The small diameter of the string limits the cross-sectional area open to flow. Furthermore, the tubing curvature causes secondary flow and results in extra flow resistance. This increased frictional pressure loss results in high surface pumping pressure. The maximum possible pump rate and sand concentration, therefore, have to be reduced. To design a CT fracturing job properly, it is essential to predict the frictional pressure loss through the tubing accurately. This paper presents correlations for the prediction of frictional pressure loss of fracturing slurries in straight tubing and CT. They are developed on the basis of full-scale slurry-flow tests with 11/2-in. CT and slurries prepared with 35 lbm/1,000 gal of guar gel. The extensive experiments were conducted at the full-scale CT-flow test facility. The proposed correlations have been verified with the experimental data and actual field CT-fracturing data. Case studies of wells recently fractured are provided to demonstrate the application of the correlations. The correlations will be useful to the CT engineers in their hydraulics design calculations.

  15. Comparison of raw dairy manure slurry and anaerobically digested slurry as N sources for grass forage production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our study was conducted to determine how raw dairy slurry and anaerobically digested slurry (dairy slurry and food waste) applied via broadcast and subsurface deposition to reed canary grass (Phalaris arundinacea) affected forage biomass, N uptake, apparent nitrogen recovery (ANR), and soil nitrate...

  16. Combustion behavior of low rank coal water slurries

    SciTech Connect

    Yavuz, R.; Kuecuekbayrak, S.; Williams, A.

    1996-12-31

    Coal water slurries have been developed over the last 15 years as an alternative to fuel oil mainly in industry and power station boilers. Observing of droplet lifetime reveals details of the mechanism of the slurry combustion. In the present investigation, single droplet combustion of lignite water slurries using different Turkish lignites were experimentally studied by using single droplet combustion technique. The technique is based on thermometric method. Results of combustion behavior of low rank coal water slurries were compared with that of high rank coal water slurries which were found in the literature.

  17. RHEOLOGICAL AND ELEMENTAL ANALYSES OF SIMULANT SB5 SLURRY MIX EVAPORATOR-MELTER FEED TANK SLURRIES

    SciTech Connect

    Fernandez, A.

    2010-02-08

    (OH){sub 2} and Mn(OH){sub 2} caused the increase in yield stress. The low pH run exhibited as much as an order of magnitude greater B and Li (frit components) leachate concentrations in the supernate. At high pH a decrease of B leaching was found and this was attributed to adsorption onto Mg(OH){sub 2}. A second leaching experiment was performed without any sludge to deconvolute the leach rate behavior of Frit 418 from those of the SB5 sludge-Frit 418 system. At high pH, the sludgeless system demonstrated very fast leaching of all the frit components, primarily due to fast dissolution of the main component, silica, by hydroxide anion; various semiconductor studies have established this reactivity. Overall, the frit-water system exhibited greater leaching from a factor two to almost three orders of magnitude (varying by conditions and species). The slower leaching of the sludge system is possibly due to a greater ionic strength or smaller driving force. Another possible reason is a physical effect, coating of the frit particles with sludge; this would increase the mass transfer resistance to leaching. Based on this study, the cause of clogs in the melter feed loop is still unknown. A possible explanation is that the SME product, like the simulant, is too thin and could contribute to a loss of two-phase flow which could cause plugging of a restricted and poorly mixed zone like the melter feed loop. This is feasible since a previous study of a slurry showed an increase in resistance to flow at lower flow rates. Testing with a radioactive SME sample is underway and should help understand this potential mechanism.

  18. Navier-Stokes analysis of radial turbine rotor performance

    NASA Technical Reports Server (NTRS)

    Larosiliere, L. M.

    1993-01-01

    An analysis of flow through a radial turbine rotor using the three-dimensional, thin-layer Navier-Stokes code RVC3D is described. The rotor is a solid version of an air-cooled metallic radial turbine having thick trailing edges, shroud clearance, and scalloped-backface clearance. Results are presented at the nominal operating condition using both a zero-clearance model and a model simulating the effects of the shroud and scalloped-backface clearance flows. A comparison with the available test data is made and details of the internal flow physics are discussed, allowing a better understanding of the complex flow distribution within the rotor.

  19. COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS

    SciTech Connect

    Paul C.K. Lam; Isaac K. Gamwo; Dimitri Gidaspow

    2002-05-01

    The objective of this study was to develop a predictive experimentally verified computational fluid dynamics (CFD) model for gas-liquid-solid flow. A three dimensional transient computer code for the coupled Navier-Stokes equations for each phase was developed and is appended in this report. The principal input into the model is the viscosity of the particulate phase which was determined from a measurement of the random kinetic energy of the 800 micron glass beads and a Brookfield viscometer. The details are presented in the attached paper titled ''CFD Simulation of Flow and Turbulence in a Slurry Bubble Column''. This phase of the work is in press in a referred journal (AIChE Journal, 2002) and was presented at the Fourth International Conference on Multiphase Flow (ICMF 2001) in New Orleans, May 27-June 1, 2001 (Paper No. 909). The computed time averaged particle velocities and concentrations agree with Particle Image Velocimetry (PIV) measurements of velocities and concentrations, obtained using a combination of gamma-ray and X-ray densitometers, in a slurry bubble column, operated in the bubbly-coalesced fluidization regime with continuous flow of water. Both the experiment and the simulation show a down-flow of particles in the center of the column and up-flow near the walls and nearly uniform particle concentration. Normal and shear Reynolds stresses were constructed from the computed instantaneous particle velocities. The PIV measurement and the simulation produced instantaneous particle velocities. The PIV measurement and the simulation produced similar nearly flat horizontal profiles of turbulent kinetic energy of particles. To better understand turbulence we studied fluidization in a liquid-solid bed. This work was also presented at the Fourth International Conference on Multiphase Flow (ICMF 2001, Paper No. 910). To understand turbulence in risers, measurements were done in the IIT riser with 530 micron glass beads using a PIV technique. This report

  20. Evaluation of slurry characteristics for rechargeable lithium-ion batteries

    SciTech Connect

    Cho, Ki Yeon; Kwon, Young Il; Youn, Jae Ryoun; Song, Young Seok

    2013-08-01

    Graphical abstract: - Highlights: • Lithium-ion battery slurries are prepared for rechargeable batteries. • The dispersion state of slurry constituents is identified. • Thermal, morphological, rheological, and electrical properties of slurries are analyzed. - Abstract: A multi-component slurry for rechargeable batteries is prepared by dispersing LiCoO{sub 2}, conductive additives, and polymeric binders in a solvent. The physical properties, including rheological, morphological, electrical, and spectroscopic features of battery slurries are investigated. The relationship between the measured physical properties and the internal structure of the slurry is analyzed. It is found that the rheological behavior of the slurry is determined by the interaction of active materials and binding materials (e.g., network structure) and that the dispersion state of conductive additives (e.g., agglomeration) also depends on the binder–carbon interaction.

  1. Elemental analysis of slurry samples with laser induced breakdown spectroscopy

    SciTech Connect

    Eseller, Kemal E.; Tripathi, Markandey M.; Yueh, Fang-Yu; Singh, Jagdish P.

    2010-05-01

    Direct analysis of wet slurry samples with laser induced breakdown spectroscopy (LIBS) is challenging due to problems of sedimentation, splashing, and surface turbulence. Also, water can quench the laser plasma and suppress the LIBS signal, resulting in poor sensitivity. The effect of water on LIBS spectra from slurries was investigated. As the water content decreased, the LIBS signal was enhanced and the standard deviation was reduced. To improve LIBS slurry analysis, dried slurry samples prepared by applying slurry on PVC coated slides were evaluated. Univariate and multivariate calibration was performed on the LIBS spectra of the dried slurry samples for elemental analysis of Mg, Si, and Fe. Calibration results show that the dried slurry samples give a good correlation between spectral intensity and elemental concentration.

  2. Radial Rydberg wavepacket maps

    NASA Astrophysics Data System (ADS)

    Zeibel, J. G.; Jones, R. R.

    2001-04-01

    Picosecond laser pulses have been used to excite radial Rydberg wavepackets in Ca. Time-delayed, unipolar, `half-cycle' electric field pulses are used to probe the evolution of the wavepackets as a continuous function of binding energy. The data provide three-dimensional maps of wavepacket recurrence probability versus binding energy versus time. A rescaling of the energy and time coordinate axes allows the visualization of the distinct difference between the initial oscillations of the wavepacket and those that occur at integer and fractional revivals.

  3. Radial reflection diffraction tomography

    DOEpatents

    Lehman, Sean K.

    2012-12-18

    A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a "pitch/catch" operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes.

  4. Radial Reflection diffraction tomorgraphy

    DOEpatents

    Lehman, Sean K

    2013-11-19

    A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a "pitch/catch" operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes.

  5. Underground radial pipe network

    SciTech Connect

    Peterson, D.L.

    1984-04-24

    The network, useful in conducting fluids to underground sites, is an assembly of flexible pipes or tubes, suspended from and connected to a drill pipe. The flexible pipes, assembled in a bundle, are spring biased to flare outwardly in an arcuate manner when a releasable cap on the distal end of the bundle is removed. The assembled bundle is inserted into and lowered down a bore hole. When the cap is released, the pipes flare radially and outwardly. Fluid, pumped into and through the assembly, can be directed into the underground formation for various purposes.

  6. Radial cutting torch

    SciTech Connect

    Robertson, M.C.

    1997-01-08

    The project`s aim is to complete development of the Radial Cutting Torch, a pyrotechnic cutter, for use in all downhole tubular cutting operations in the petroleum industry. Project objectives are to redesign and pressure test nozzle seals to increase product quality, reliability, and manufacturability; improve the mechanical anchor to increase its temperature tolerance and its ability to function in a wider variety of wellbore fluids; and redesign and pressure test the RCT nozzle for operation at pressures from 10 to 20 ksi. The proposal work statement is included in the statement of work for the grant via this reference.

  7. Experimental feasibility study of radial injection cooling of three-pad radial air foil bearings

    NASA Astrophysics Data System (ADS)

    Shrestha, Suman K.

    Air foil bearings use ambient air as a lubricant allowing environment-friendly operation. When they are designed, installed, and operated properly, air foil bearings are very cost effective and reliable solution to oil-free turbomachinery. Because air is used as a lubricant, there are no mechanical contacts between the rotor and bearings and when the rotor is lifted off the bearing, near frictionless quiet operation is possible. However, due to the high speed operation, thermal management is one of the very important design factors to consider. Most widely accepted practice of the cooling method is axial cooling, which uses cooling air passing through heat exchange channels formed underneath the bearing pad. Advantage is no hardware modification to implement the axial cooling because elastic foundation structure of foil bearing serves as a heat exchange channels. Disadvantage is axial temperature gradient on the journal shaft and bearing. This work presents the experimental feasibility study of alternative cooling method using radial injection of cooling air directly on the rotor shaft. The injection speeds, number of nozzles, location of nozzles, total air flow rate are important factors determining the effectiveness of the radial injection cooling method. Effectiveness of the radial injection cooling was compared with traditional axial cooling method. A previously constructed test rig was modified to accommodate a new motor with higher torque and radial injection cooling. The radial injection cooling utilizes the direct air injection to the inlet region of air film from three locations at 120° from one another with each location having three axially separated holes. In axial cooling, a certain axial pressure gradient is applied across the bearing to induce axial cooling air through bump foil channels. For the comparison of the two methods, the same amount of cooling air flow rate was used for both axial cooling and radial injection. Cooling air flow rate was

  8. Management of an iatrogenic radial artery perforation: a case report.

    PubMed

    Buturak, Ali; Demirci, Yasemin; Dağdelen, Sinan

    2013-06-01

    A 73-year-old female patient underwent transradial coronary angiography with stable angina and signs of significant myocardial ischemia revealed by exercise stress test. After insertion of a 6F radial sheath into the right radial artery and intra-arterial administration of heparin plus verapamil, the hydrophilic guidewire could not be advanced under fluoroscopic guidance. Immediately afterwards, radial angiography was performed, which displayed a radial artery perforation with significant contrast extravasation. The perforated segment was crossed meticulously with the same guidewire after additional vasodilator drug administration. Afterwards, a 5F TIG catheter was advanced to the axillary artery and held in place for 20 minutes with application of external compression with a sphygmomanometer cuff at the level of systolic blood pressure. The same maneuver was again performed following cuff deflation and completion of coronary angiography with the 5F catheter. Final angiography displayed complete sealing of the perforation without a need for neutralization of heparin. External compression was continued for two hours, and after documentation of normal triphasic radial artery flow by Doppler ultrasound (DUS), the radial sheath was removed. The patient was discharged the following day with no evidence of hand ischemia and well-palpable radial artery pulse. DUS demonstrated normal radial artery flow one month later. This unusual complication was managed successfully with a simple and easily applicable technique that can be performed in such cases. PMID:23760121

  9. Physical Characterization of Solid-Liquid Slurries at High Weight Fractions Using Optical and Ultrasonic Methods

    SciTech Connect

    Burgess, L.W.; Brodsky, A.M.; Panetta P.D.

    2005-12-22

    Remediation of highly radioactive waste is a major technical and programmatic challenge for the DOE. Rapid, on-line physical characterization of highly concentrated slurries is required for the safe and efficient remediation of 90 million gallons of high level radioactive waste (HLW), sodium bearing waste, and mixed waste. The research presented here, describes a collaborative effort between Pacific Northwest National Laboratory (PNNL) and the University of Washington (UW) to directly address the need for rapid on-line characterization of the physical properties of HLW slurries during all phases of the remediation process, from in-tank characterization of sediments to monitoring of the concentration, particle size, and degree of agglomeration and gelation of slurries during transport. Near-surface characterization of the slurry flow in the particle size range from nanometer to micrometer is examined using optical low coherence reflectometry. Volumetric characterization at depths in the slurry flow, up to several centimeters in the particle size range from the micrometer to millimeter, is realized by utilizing ultrasonic backscatter and diffuses fields. One of the strengths, the teaming up of significant talents in both experimental and theoretical optics and in ultrasonics, provides a synergistic approach to integrate these complimentary techniques. One of the benefits of this combined approach is the physical characterization of HLW over a concentration and particle size range that is broader than can be achieved with today's technology. This will avoid a costly increase in waste stream volume due to excess dilution, and will lessen chance of plugging pipes that could shut down expensive processing lines.

  10. Enhanced photocatalysis in a pilot laminar falling film slurry reactor

    SciTech Connect

    Puma, G.L.; Yue, P.L.

    1999-09-01

    Laminar falling film slurry (LFFS) photocatalytic reactors are one of the most efficient reactor configurations for conducting heterogeneous photocatalytic reactions, particularly for wastewater treatment. This paper presents a study on the oxidation of an aqueous salicylic acid waste in a pilot continuous flow LFFS photocatalytic reactor which has an optimum design for light absorption. In conducting the oxidation reaction, heterogeneous photocatalysis was supplemented with other photon-assisted processes. The effect of light intensity, radiation wavelength, oxidizing-enhancing agents, substrate and photocatalyst concentration, and exposure time were studied. A comparison of six different photon-based processes showed that higher oxidation rates of salicylic acid were obtained when there was concomitant photocatalysis, photolysis, and UV peroxidation. The oxidation rates of salicylic acid with this combined process were at least 1 order of magnitude higher in comparison with those for UVA photocatalysis and 3-fold higher in comparison with homogeneous UVC photolysis/UVC peroxidation.

  11. Augmenting groundwater monitoring networks near landfills with slurry cutoff walls.

    PubMed

    Hudak, Paul F

    2004-01-01

    This study investigated the use of slurry cutoff walls in conjunction with monitoring wells to detect contaminant releases from a solid waste landfill. The 50 m wide by 75 m long landfill was oriented oblique to regional groundwater flow in a shallow sand aquifer. Computer models calculated flow fields and the detection capability of six monitoring networks, four including a 1 m wide by 50 m long cutoff wall at various positions along the landfill's downgradient boundaries and upgradient of the landfill. Wells were positioned to take advantage of convergent flow induced downgradient of the cutoff walls. A five-well network with no cutoff wall detected 81% of contaminant plumes originating within the landfill's footprint before they reached a buffer zone boundary located 50 m from the landfill's downgradient corner. By comparison, detection efficiencies of networks augmented with cutoff walls ranged from 81 to 100%. The most efficient network detected 100% of contaminant releases with four wells, with a centrally located, downgradient cutoff wall. In general, cutoff walls increased detection efficiency by delaying transport of contaminant plumes to the buffer zone boundary, thereby allowing them to increase in size, and by inducing convergent flow at downgradient areas, thereby funneling contaminant plumes toward monitoring wells. However, increases in detection efficiency were too small to offset construction costs for cutoff walls. A 100% detection efficiency was also attained by an eight-well network with no cutoff wall, at approximately one-third the cost of the most efficient wall-augmented network. PMID:15887367

  12. In-line ultrasonic monitoring of waste slurry suspended solids

    SciTech Connect

    Chien, H.-T.; Sheen, S.-H.; Raptis, A. C.

    2000-05-25

    During the transport of tank waste, it is very important to quantitatively measure the percent solids concentration (PSC) of the waste, which indicates the flow conditions and the extent of solids settling. At Argonne National Laboratory, an in-line, real-time, a nonintrusive ultrasonic monitoring system has been developed to measure the PSC and flow density of tank waste by measuring sound velocity and attenuation in the flow. This system consists of a pair of longitudinal transducers bonded to waveguides on the opposite sides of the pipe and operating at IMHz simultaneously in pulse-and-echo and pitch-and-catch modes. The PSC measurement is provided by attenuation, while the density measurement is calculated by impedance and sound velocity. A thermocouple is attached to one of the waveguides for automatic temperature correction of the measurements. This system was one of four evaluated for in-line measurement of slurry at Oak Ridge National Laboratory in 1998. The results indicate that the measurements are in good agreement with a Coriolis meter and that the system can be used to monitor PSC up to 40 wt.%. However, the system is greatly affected by entrained air bubbles within the solid flow during Puisair mixing. A different mixing mechanism will solve this problem.

  13. Ultrasonic Method for Concentration and Particle Size Analysis in Dense Coal-water Slurry

    NASA Astrophysics Data System (ADS)

    Xue, Minghua; Su, Mingxu; Dong, Lili; Shang, Zhitao; Cai, Xiaoshu

    2007-06-01

    The concentration and particle size distribution in particulate two-phase flow are the important parameters in a wide variety of industrial areas. For the purpose of on-line characterizing dense coal-water slurry, ultrasonic methods have many advantages, such as no-dilution, real-time and no-invasion, while light-based techniques are not capable of providing information because optical methods normally require the sample to be diluted. In this paper, the modified Urick equation including temperature modification, which can be used to determine concentration from the measurement of velocity in the coal-water slurry, is evaluated on the basis of model analysis and experiments. Combined with the optimum regulation technique inverse algorithm, the particle size distribution of the coal-water slurry is obtained according to the attenuation prediction of Coupled-phase model plus Bouguer-Lambert-Beer-Law scattering model and experimental attenuation at frequencies ranges from 3MHz to 12MHz. This technique brings the possibility of using ultrasound for on-line measurement of dense slurry.

  14. Rebirth of left radial artery access: could this be the 'right' radial artery?

    PubMed

    Taylor, Montoya; Capers, Quinn; Patel, Dilesh; Mehta, Nishaki K

    2015-06-01

    Cardiac catheterization has several risks, notably which include bleeding, stroke and death. The transradial (TR) approach to catheterization is associated with a lower bleeding risk. The right radial approach is the default method in most laboratories and the left radial artery (LRA) serves as the bail-out approach. This article discusses the advantages and disadvantages of transfemoral and TR access routes. The authors envisage an increased adoption of the LRA approach, due to the anatomical superiority and ease of catheter engagement afforded by this approach. The authors discuss ways to increase operator ease for LRA in the laboratory and propose a novel way to improve LRA work-flow. PMID:26000561

  15. System description of the ANL (Argonne National Laboratory) Slurry Loop Testing facility (SLTF)

    SciTech Connect

    Porges, K.G.; Cox, S.A.; Brewer, W.E.; Hacker, D.S.

    1986-09-01

    This report describes a test loop specifically designed for dense slurries. The loop provides flow velocity and medium composition calibrations within 1%, as well as online rheometric characterization in non-Newtonian, laminar flow, by means of several unique calibration facilities developed at Argonne National Laboratory. Two horizontal test sections of 6 and 12 m length, as well as a vertical test section of 6 m length, are provided for flowmeter calibration; up to 5 flowmeters can be accommodated simultaneously. In addition to the online calibration schemes, which rank this test loop among the most accurate facilities currently existing, extensive laboratory characterization of grab samples is available. Initial work with coal/oil and coal/water slurries ranged over 60% solids. 18 refs., 26 figs., 1 tab.

  16. Cementing steamflood and fireflood wells - slurry design

    SciTech Connect

    Nelson, E.B.; Eilers, L.H.

    1983-01-01

    Steamflood and fireflood wells present special challenges when designing a cement slurry. In most cases, the cement slurry is subjected to relatively low temperature during the cement job and early curing. However, after the cement sets, it must be able to withstand the thermal shock associated with the initiation of steamflooding or fireflooding. In addition, the cement must be able to preserve adequate compressive strength and low permeability despite the potentially disruptive crystalline changes that occur at high temperatures. Another complicating factor is the weak or incompetent formations often encountered with thermal recovery wells. This work discusses the chemical and phase equilibria relationships which prevail when cements are exposed to the high temperatures associated with fireflood and steamflood wells.

  17. Computational modeling of dilute biomass slurries

    NASA Astrophysics Data System (ADS)

    Sprague, Michael; Stickel, Jonathan; Fischer, Paul; Lischeske, James

    2012-11-01

    The biochemical conversion of lignocellulosic biomass to liquid transportation fuels involves a multitude of physical and chemical transformations that occur in several distinct processing steps (e.g., pretreatment, enzymatic hydrolysis, and fermentation). In this work we focus on development of a computational fluid dynamics model of a dilute biomass slurry, which is a highly viscous particle-laden fluid that can exhibit yield-stress behavior. Here, we model the biomass slurry as a generalized Newtonian fluid that accommodates biomass transport due to settling and biomass-concentration-dependent viscosity. Within a typical mixing vessel, viscosity can vary over several orders of magnitude. We solve the model with the Nek5000 spectral-finite-element solver in a simple vane mixer, and validate against experimental results. This work is directed towards our goal of a fully coupled computational model of fluid dynamics and reaction kinetics for the enzymatic hydrolysis of lignocellulosic biomass.

  18. CST Suspension Analysis for Slurry Pumps of Tank 40

    SciTech Connect

    LEE, SIY.

    2004-04-01

    result s. The model results show that at least two pumps on opposite sides could keep suspending the CST material based on the slurry with 35 wt contents, but that at lower concentrations, particles larger than about 400 microns would tend to settle quickly and probably not remain in suspension long enough for the opposite jet to come around and stir that region of the tank. The main conclusions are as follows: The steady-state flow patterns on the horizontal discharge plane follow a series of parabolic curves similar to that of a free jet available in the literature. For the simulations, a series of the modeling calculations was performed with indexed stationary and rotating pump operations. The calculated results demonstrated that the existing slurry pumps running at 7600 gpm could suspend the CST particles from the tank with a 200 in liquid level, based on a minimum sludge suspension velocity of about 1.1 ft/sec for 700 micron CST particle. The suspension distance for the transient model with pump rotations is smaller than that of the steady-state model with indexed pump orientations for given operating conditions. However, total suspension extents for the two modeling cases have about the same area.

  19. Liquid CO{sub 2}/Coal Slurry for Feeding Low Rank Coal to Gasifiers

    SciTech Connect

    Marasigan, Jose; Goldstein, Harvey; Dooher, John

    2013-09-30

    electricity computed for the liquid CO{sub 2}/coal slurry cases is greater for both PRB and ND Lignite coals. It does not appear that there is any benefit to using liquid CO{sub 2}/coal slurries for feeding low rank coals to the E-Gas™ gasifier. Any incidental benefits in improved cold gas efficiency are more than compensated for in higher overall plant costs, increased complexity, and reduced power output and efficiency. The results of the study are compared with previous published analyses, and the differences in model assumptions, approach and basis are summarized. It has been concluded that the use of liquid CO{sub 2} may still prove to have a significant advantage in a different type of gasifier, i.e., single-stage entrained flow with radiant quench section, but some key questions remain unanswered that can validate the potential improvement of gasifier performance using liquid CO{sub 2} slurries. In order to provide a path to answering these questions, a technology development roadmap has been developed to resolve fundamental issues and to better define the operation aspects of using liquid CO{sub 2}/coal slurries. The fundamental issues could be resolved by conducting additional laboratory analyses consisting of: • A rheological test program to quantitatively evaluate slurry preparation and handling for liquid CO{sub 2} including experiments to evaluate preparation systems. • An experimental program on CO{sub 2}-assisted gasification in order to obtain the most relevant experimental data from drop tube furnace studies to aid in verifying the potential advantages of direct feed of liquid CO{sub 2}/coal as gasifier feedstocks. Quantifying the operational aspects of liquid CO{sub 2} slurries can best be achieved with: • An experimental program using a flow test loop to evaluate equipment performance and handling properties of liquid CO{sub 2}/coal slurries for gasifier feedstocks on a scale sufficient to predict full scale operating parameters. • Spray

  20. Clean coal slurry pipelines in China

    SciTech Connect

    Horton, R.

    1994-12-31

    China Pipeline Holdings Limited, managed by Custom Coals Corporation, has formed a joint venture with the Chinese government, called China Coal Pipeline Company, to build and operate coal slurry pipelines in China. Carrying cleaned coal and financed on the strength of coal contracts, pipelines offer an environmentally sound and cost effective alternative to alleviate transportation bottlenecks and help meet the energy demands of China`s phenomenal growth.

  1. Abrasive slurry composition for machining boron carbide

    DOEpatents

    Duran, Edward L.

    1985-01-01

    An abrasive slurry particularly suited for use in drilling or machining boron carbide consists essentially of a suspension of boron carbide and/or silicon carbide grit in a carrier solution consisting essentially of a dilute solution of alkylaryl polyether alcohol in octyl alcohol. The alkylaryl polyether alcohol functions as a wetting agent which improves the capacity of the octyl alcohol for carrying the grit in suspension, yet without substantially increasing the viscosity of the carrier solution.

  2. Abrasive slurry composition for machining boron carbide

    DOEpatents

    Duran, E.L.

    1984-11-29

    An abrasive slurry particularly suited for use in drilling or machining boron carbide consists essentially of a suspension of boron carbide and/or silicon carbide grit in a carrier solution consisting essentially of a dilute solution of alkylaryl polyether alcohol in octyl alcohol. The alkylaryl polyether alcohol functions as a wetting agent which improves the capacity of the octyl alcohol for carrying the grit in suspension, yet without substantially increasing the viscosity of the carrier solution.

  3. Computer simulation of heat transfer mechanism in SRC-I slurry fired heater

    SciTech Connect

    Mehta, D.C.; Fox, V.G.; Weimer, R.F.

    1984-05-01

    A computer simulation of the heat transfer mechanism was performed for the slurry fired heater in the SRC-I Demonstration Plant. The operating conditions were based on the fired heater design, and the data on pressure drop, slug characteristics, and heat transfer were obtained from the cold-flow modelling experiments at Creare, Inc. The computer program solves the partial differential equation describing heat transfer in the fired heater pipe. 7 references, 6 figures, 5 tables.

  4. Strategy Plan A Methodology to Predict the Uniformity of Double-Shell Tank Waste Slurries Based on Mixing Pump Operation

    SciTech Connect

    J.A. Bamberger; L.M. Liljegren; P.S. Lowery

    1990-12-01

    This document presents an analysis of the mechanisms influencing mixing within double-shell slurry tanks. A research program to characterize mixing of slurries within tanks has been proposed. The research program presents a combined experimental and computational approach to produce correlations describing the tank slurry concentration profile (and therefore uniformity) as a function of mixer pump operating conditions. The TEMPEST computer code was used to simulate both a full-scale (prototype) and scaled (model) double-shell waste tank to predict flow patterns resulting from a stationary jet centered in the tank. The simulation results were used to evaluate flow patterns in the tank and to determine whether flow patterns are similar between the full-scale prototype and an existing 1/12-scale model tank. The flow patterns were sufficiently similar to recommend conducting scoping experiments at 1/12-scale. Also, TEMPEST modeled velocity profiles of the near-floor jet were compared to experimental measurements of the near-floor jet with good agreement. Reported values of physical properties of double-shell tank slurries were analyzed to evaluate the range of properties appropriate for conducting scaled experiments. One-twelfth scale scoping experiments are recommended to confirm the prioritization of the dimensionless groups (gravitational settling, Froude, and Reynolds numbers) that affect slurry suspension in the tank. Two of the proposed 1/12-scale test conditions were modeled using the TEMPEST computer code to observe the anticipated flow fields. This information will be used to guide selection of sampling probe locations. Additional computer modeling is being conducted to model a particulate laden, rotating jet centered in the tank. The results of this modeling effort will be compared to the scaled experimental data to quantify the agreement between the code and the 1/12-scale experiment. The scoping experiment results will guide selection of parameters to be

  5. Slurry-phase Fischer-Tropsch synthesis

    SciTech Connect

    Zarochak, M.F.; McDonald, M.A.

    1986-01-01

    Fischer-Tropsch synthesis in the slurry phase has attracted attention in recent years due to its numerous advantages. Among these advantages are the ability of the liquid phase to handle the large heats of reaction and thereby control reaction temperature, the ability to handle low H/sub 2//CO ratio synthesis gas without needing a preliminary water-gas shift step, and the relatively low capital and operating costs for slurry systems. Slurry-phase work at PETC has focused on understanding effects of catalyst preparation and pretreatment, of reaction conditions (T, P, H/sub 2//CO), and of operating conditions (space velocity, methods of wax removal) on catalyst synthesis behavior (activity, selectivity, and maintenance of activity and selectivity). Better understanding of the effects of these factors on F-T synthesis leads to improvements in process technology. This work focuses on the effects of catalyst pretreatment on synthesis behavior. Developing an effective F-T catalyst pretreatment procedure is a problem limited almost exclusively to iron catalysts. This paper reports some recent results on the effects of pretreatment. Synthesis runs were made using one of two different pretreatments given a potassium-promoted precipitated iron catalyst. Besides these reaction experiments, catalyst samples were periodically withdrawn from the stirred autoclave for characterization by means of Moessbauer spectroscopy.

  6. Coal slurry pipelines: impact on coal markets. [Contains description of 11 proposed slurry pipelines

    SciTech Connect

    Hong, B.D.; Hickman, J.G.; Schnapp, R.M.

    1985-04-01

    This analysis indicates that: Coal slurry pipelines could be competitive with railroads, if the projected pipeline and rail rates actually prevailed; coal users could realize savings of between $200 million and $1 billion in 1995, if the four coal slurry pipelines analyzed were built and operated at the estimated rates; the railroads could be adversely affected by coal slurry pipeline operations (about 8% less revenues with between 44 and 48 million tons of coal carriage lost), but railroad revenues from hauling coal in 1995 would still be between about one-half and two-thirds greater than those of 1984; and only minor shifts in the regional coal production pattern would occur as a result of coal slurry pipeline operations. This analysis has qualifications and limitations just as any other analysis. The coal pipeline rates used in this analysis may not necessarily be the actual rates that would prevail. This analysis considered neither the costs associated with retrofitting existing power plants to burn coal slurry nor other possible benefits of burning coal slurry. Rail rates, reflecting rail costs, were assumed to rise at slow but steady rate in the future; the potential for the railroads to lower their rates to overcome competition from coal pipelines was not considered. It is important to note that neither the grant of federal eminent domain for coal pipelines nor the potential transportation cost savings from coal pipeline operation can guarantee actual construction of coal pipelines. Eminent domain, however, would certainly remove the barriers to market entry that prevent competition. Actual construction of coal pipelines will depend largely on whether electric utility operators perceive their potential cost savings to be sufficiently large to warrant the risks associated with coal pipelines. 4 figs., 12 tabs.

  7. Radial gate hoist mechanisms mounted above radial gates, view to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Radial gate hoist mechanisms mounted above radial gates, view to the east - Wellton-Mohawk Irrigation System, Wasteway No. 1, Wellton-Mohawk Canal, North side of Wellton-Mohawk Canal, bounded by Gila River to North & the Union Pacific Railroad & Gila Mountains to south, Wellton, Yuma County, AZ

  8. Radially composite piezoelectric ceramic tubular transducer in radial vibration.

    PubMed

    Shuyu, Lin; Shuaijun, Wang

    2011-11-01

    The radially composite piezoelectric tubular transducer is studied. It is composed of radially poled piezoelectric and a long metal tube. The electro-mechanical equivalent circuit of the radially poled piezoelectric and metal tube in radial vibration is obtained. Based on the force and velocity boundary conditions, the six-port electro-mechanical equivalent circuit for the composite tubular transducer is given and the resonance/anti-resonance frequency equations are obtained. The relationship between the resonance frequency and the dimensions is analyzed. Numerically simulated results obtained by the finite element method are compared with those from the analytical method. Composite piezoelectric tubular transducers are designed and manufactured. The resonance/anti-resonance frequencies are measured, and it is shown that the theoretical results are in good agreement with the simulated and experimental results. It is expected that radially composite piezoelectric tubular transducers can be used as high-power ultrasonic radiators in ultrasonic applications, such as ultrasonic liquid processing. PMID:22083782

  9. Survey of state water laws affecting coal slurry pipeline development

    SciTech Connect

    Rogozen, M.B.

    1980-11-01

    This report summarizes state water laws likely to affect the development of coal slurry pipelines. It was prepared as part of a project to analyze environmental issues related to energy transportation systems. Coal slurry pipelines have been proposed as a means to expand the existing transportation system to handle the increasing coal shipments that will be required in the future. The availability of water for use in coal slurry systems in the coal-producing states is an issue of major concern.

  10. Ice slurry cooling research: Storage tank ice agglomeration and extraction

    SciTech Connect

    Kasza, K.; Hayashi, Kanetoshi

    1999-08-01

    A new facility has been built to conduct research and development on important issues related to implementing ice slurry cooling technology. Ongoing studies are generating important information on the factors that influence ice particle agglomeration in ice slurry storage tanks. The studies are also addressing the development of methods to minimize and monitor agglomeration and improve the efficiency and controllability of tank extraction of slurry for distribution to cooling loads. These engineering issues impede the utilization of the ice slurry cooling concept that has been under development by various groups.

  11. Oxidation of coal-water slurry feed to hydrogasifier

    DOEpatents

    Lee, Bernard S.

    1976-01-01

    An aqueous coal slurry is preheated, subjected to partial oxidation and vaporization by injection of high pressure oxygen and is introduced into a top section of a hydrogasifier in direct contact with hot methane-containing effluent gases where vaporization of the slurry is completed. The resulting solids are reacted in the hydrogasifier and the combined gases and vapors are withdrawn and subjected to purification and methanation to provide pipeline gas. The amount of oxygen injected into the slurry is controlled to provide the proper thermal balance whereby all of the water in the slurry can be evaporated in contact with the hot effluent gases from the hydrogasifier.

  12. DESIGN ANALYSIS OF RADIAL INFLOW TURBINES

    NASA Technical Reports Server (NTRS)

    Glassman, A. J.

    1994-01-01

    This program performs a velocity-diagram analysis required for determining geometry and estimating performance for radial-inflow turbines. Input design requirements are power, mass flow rate, inlet temperature and pressure, and rotative rate. The design variables include stator-exit angle, rotor-exit-tip to rotor-inlet radius ratio, rotor-exit-hub to tip radius ratio, and the magnitude and radial distribution of rotor-exit tangential velocity. The program output includes diameters, total and static efficiences, all absolute and relative temperatures, pressures, and velocities, and flow angles at stator inlet, stator exit, rotor inlet, and rotor exit. Losses accounted for in this program by the internal loss model are three-dimensional (profile plus end wall) viscous losses in the stator and the rotor, the disk-friction loss on the back side of the rotor, the loss due to the clearance between the rotor tip and the outer casing, and the exit velocity loss. The flow analysis is one-dimensional at the stator inlet, stator exit, and rotor inlet, each of these calculation stations being at a constant radius. At the rotor exit where there is a variation in flow-field radius, an axisymmetric two-dimensional analysis is made using constant height sectors. Simple radial equilibrium is used to establish the static pressure gradient at the rotor exit. This program is written in FORTRAN V and has been implemented on a UNIVAC 1100 series computer with a memory requirement of approximately 22K of 36 bit words.

  13. Values of Particle Size Particle Density & Slurry Viscosity to use in Waste Feed Delivery Transfer System Analysis

    SciTech Connect

    JEWETT, J R

    2002-01-30

    Recommended values have been developed for particle size distribution, particle density, and slurry viscosity that maybe used in slurry flow calculations that support the design of the piping system that is being modified to deliver Hanford wastes from the underground storage tanks to the planned Waste Treatment Plant for vitrification. The objective of this document is to provide recommended values for three waste properties to be used in a planned revision of the Waste Feed Delivery Transfer System Analysis. These properties are particle size distribution (PSD), particle density, and slurry viscosity. In this document, the results of laboratory and engineering studies will be collated and summarized to provide a succinct source of physical property data for use in the hydraulic analysis of the transfer system.

  14. Synthesis of octane enhancers during slurry-phase Fischer-Tropsch. [801Methyl tert-butyl ether

    SciTech Connect

    Marcelin, G.

    1992-06-24

    The objective of this project is to investigate three possible routes to the formation of ethers, in particular methyl tert-butyl ether (MTBE), during slurry phase Fischer-Tropsch reaction. The three reaction schemes to be investigated are: (1) Addition of isobutylene during the formation of methanol and/or higher alcohols directly from CO and H{sub 2} during slurry-phase Fischer-Tropsch. (2) Addition of isobutylene to FT liquid products including alcohols in a slurry-phase reactor containing an MTBE or other acid catalyst. (3) Addition of methanol to slurry phase FT synthesis making iso-olefins. During the sixth quarter we completed the construction of the slurry bubble column reactor (SBCR), conducted initial shake-down experiments in a cold-flow mode, and finalized the selection process of the acid catalysts for conversion of syngas-produced alcohols and isobutylene to MTBE (scheme 2). Tasks 3, 4, and 5 are awaiting complete implementation of the SBCR system.

  15. Computer Simulation of the Propagation of Heat in Abandoned Workings Insulated with Slurries and Mineral Substances

    NASA Astrophysics Data System (ADS)

    Dziurzyński, Wacław; Krach, Andrzej; Pałka, Teresa

    2014-03-01

    In the paper the results of investigations aimed at further identification of the phenomena occurring in abandoned workings and connected with the flow of air-gas (methane, carbon dioxide, nitrogen, oxygen and carbon oxidation products) mixture with taking into consideration the impact of supplied mineral substances on the processes of self-heating of the coal left in goaves were presented. The known and successfully used method for the prevention of fires in abandoned workings is the technology of filling goaf with an ash-air mixture, which also raises the issue of the effective use of that mixture. The computer, i.e. digital simulation methods being developed and intended for the purpose of the process discussed here are a good complement of the use of that technology. A developed mathematical model describing the process of additional sealing of gob with wet slurry supplied with three pipelines is based on the balance of volume of the supplied mixture and contained in the body created in goaves. The form of that body was assessed on the basis of the observation results available in literature and the results of model investigations. The calculation examples carried out for the the longwall area and its goaf ventilated with the "U" system allow to state that the introduced modification of the mathematical model describing the flow of the mixture of air, gases, and wet slurry with consideration of the coal burning process in the fire source area was verified positively. The digital prognostic simulations have confirmed a vital impact of the wet slurry supplied into the goaf on the processes of coal burning and also the change of rate and volume flow rate of the air mixture in goaf. As a complement to the above it should be noted that such elements as the place of the slurry supply in comparison with the longwall inclination or fire source area location is of great importance for the effectiveness of the fire prevention used. The development of computer/ digital

  16. Radial systems of dark globules

    SciTech Connect

    Gyul'budagyn, A.L.

    1986-03-01

    The author gives examples of radial systems consisting of dark globules and ''elephant trunks''. Besides already known systems, which contain hot stars at their center, data are given on three radial systems of a new kind, at the center of which there are stars of spectral types later than B. Data are given on 32 globules of radial systems of the association Cep OB2. On the basis of the observational data, it is concluded that at least some of the isolated Bok globules derive from elephant trunks and dark globules forming radial systems around hot stars. It is also suggested that the two molecular clouds situated near the Rosette nebula and possessing velocities differing by ca 20 km/sec from the velocity of the nebula could have been ejected in opposite directions from the center of the nebula. One of these clouds consists of dark globules forming the radial system of the Rosette nebula.

  17. Coal injector for coarse slurry transport. Open file report, 1 July 1975-30 April 1983

    SciTech Connect

    Burnett, M.; Rubin, L.S.; Harvey, A.; Roberge, J.C.; Cardenas, R.L.

    1983-12-01

    An inducer-type pump, capable of injecting dry coal into a hydraulic transport pipeline was developed and installed in a specially designed and fabricated slurry injector vehicle. The full-scale prototype injector system can deliver up to 11 ton/min of coal into an 8-in pipeline at pressures up to 95 lb/sq in. The helical inducer injector operates on centrifugal principles with flow passing axially through a helical-pitched conical rotor. Water is delivered to the pump through an annular slot at the atmospheric pressure coal inlet. The spinning rotor maintains an air-core vortex of water that pressurizes the discharge housing. A screw feeds coal through the open inlet into the vortex. The inner radius of the vortex contracts as pressure is increased, giving a limiting maximum pressure that is proportional to the square of the rotor speed. Below this limit, flow rate, discharge pressure, and rotor speed are independent variables. The self-powered, 42-in-high slurry injector vehicle follows and receives run-of-mine coal from a continuous miner, reduces the top size to 3-in, and delivers the sized coal to the injector feed screw for slurry formation and pumps it through a mobile hose attached to the vehicle's outby end.

  18. Effects of Iron Oxides on the Rheological Properties of Cementitious Slurry

    SciTech Connect

    Chung, Chul-Woo; Chun, Jaehun; Wang, Guohui; Um, Wooyong

    2014-04-02

    Iron oxide has been considered a promising host for immobilizing and encapsulating radioactive 99Tc (t1/2=2.1x105 year), which significantly enhances the stability of 99Tc within a cementitious waste form. However, the flow behavior of cementitious slurry containing iron oxide has never been investigated to ensure its workability, which directly influences the preparation and performance of the cementitious waste form monolith. Variation in the rheological properties of the cementitious slurry were studied using rheometry and ultrasonic wave reflection to understand the effects of various iron oxides (magnetite, hematite, ferrihydrite, and goethite) during the cement setting and stiffening processes. The rheological behavior significantly varied with the addition of different chemical compounds of iron oxides. Complementary microscopic characteristics such as colloidal vibration currents, morphology, and particle size distributions further suggest that the most adverse alteration of cement setting and stiffening behavior caused by the presence of goethite may be attributed to its acicular shape.

  19. Formulation of slurries for slurry-fed coal gasifiers: Final report

    SciTech Connect

    Butcher, T.A.; Celebi, Y.

    1987-03-01

    A 100 MW integrated gasification/combined cycle generating plant was recently put into operation at the Cool Water generating station of Southern California Edison Co. Coal is fed into the gasifier as a coal-water slurry. This report describes an experimental study on the slurryability of candidate gasifier coals and slurry formulation options for use in systems of this type. Relative to boiler and process-fuel applications, the gasifier application has some unique features. The slurry is continuously prepared on-site in wet rod mills and is stored in continuously-agitated day tanks. Stability of the slurry, then, is not a necessity. In addition, economic studies have shown that dispersant additives must be inexpensive (on the order of $.10/million Btu) to be attractive. The ten candidate coals studied ranged in equilibrium moisture from 1 to 13%. The set included Pittsburgh 8 seam coals, Illinois 6 seam coals, and one Utah coal. For three of the coals both run-of-mine and preparation-plant products were examined. Coal characterization included standard analyses, relative hydrophilic/hydrophobic nature, surface area, density, surfactant adsorption, and leachable ions. A ranking was made of the relative slurryability of the coals under two cases, with and without an added surfactant. The ranking, which was based on apparent viscosity at 100 sec/sup -1/, was somewhat different in the two cases. As others have reported, equilibrium moisture is a key parameter. Slurry formulation studies included the effects of size distribution, acid leaching, additional physical cleaning (both gravity separation and froth floatation), selected anionic and nonionic surfactants, pH, and oxidation to simulate weathering. 17 refs., 27 figs., 25 tabs.

  20. Formulation of slurries for slurry-fed coal gasifiers: Final report

    SciTech Connect

    Butcher, T.A.; Celebi, Y.

    1987-06-01

    A 100 MW integrated gasification/combined cycle generating plant was recently put into operation at the Cool Water generating station of Southern California Edison Co. Coal is fed into the gasifier as a coal-water slurry. This report describes an experimental study on the slurryability of candidate gasifier coals and slurry formulation options for use in systems of this type. The ten candidate coals studied ranged in equilibrium moisture from 1 to 13%. Coal characterization included standard analyses, relative hydrophilic/hydrophobic nature, surface area, density, surfactant adsorption, and leachable ions. A ranking was made of the relative slurryability of the coals under two cases, with and without an added surfactant. Slurry formulation studies included the effects of size distribution, acid leaching, additional physical cleaning (both gravity separation and froth flotation), selected anionic and nonionic surfactants, pH, and oxidation to simulate weathering. Slurry viscosity can be lowered by using optimized size distributions which are broader than those achieved in typical grinders. Acid leaching was found to be a very effective method of reducing slurry conductivity, which could promote dispersion of the particles. The effect on viscosity for the specific coals studied, however, was not significant. Similarly, additional physical cleaning was found to have no significant effect on coal equilibrium moisture or loadings on a weight basis. Significant loading increases could be achieved using low concentrations of surfactants alone. This is particularly true for the higher rank coals, which have lower additive demand, and have a greater viscosity reduction at the optimum additive concentration. 17 refs., 27 figs., 25 tabs.

  1. Acidification of pig slurry before separation to improve slurry management on farms.

    PubMed

    Regueiro, Iria; Coutinho, João; Balsari, Paolo; Popovic, Olga; Fangueiro, David

    2016-08-01

    Pig slurry, rich in plant nutrients such as nitrogen (N) and phosphorus (P), is generally applied to soil as organic fertilizer. However, costs related to slurry transport may limit its utilization to fields close to the farm, leading to significant N losses, namely ammonia (NH3) emissions. Slurry acidification, to minimize NH3 emissions, is a potential solution to this problem, while solid-liquid separation leads to a solid fraction (SF) - rich in organic matter (OM) and phosphorus - and a liquid fraction (LF) rich in soluble nutrients. We hypothesized that a combination of acidification and separation could affect the quality of the resulting fractions depending on the separation technique used. After acidification, the two most common techniques for separation, centrifugation (CF) and screw-press (SP), were applied. The main characteristics of the slurry fractions in terms of nutrient concentrations and speciation as well as the potential N mineralization (PNM) were analysed. Our results show SFs with improved properties, mostly N and PNM when acidification is performed before separation with both techniques. The PNM was significantly increased in LFs from both techniques after acidification. The [Formula: see text] concentration increased in LFs from SP with acidification; therefore, slurry acidification is recommended to avoid any N losses during the separation process with SP, while CF may not require such pretreatment. Acidification could allow the use of a cheaper technique such as SP relative to CF since it prevents NH3 emissions during the separation process and leads to more equilibrated fractions in terms of nutrient composition. PMID:26695081

  2. Radial and azimuthal beam parameters.

    PubMed

    Lumer, Yaakov; Moshe, Inon

    2009-02-01

    Global invariant parameters are introduced to characterize the radial and azimuthal content of totally polarized beams. Such parameters are written in terms of the second moments of the optical beam and are invariant in propagation through symmetric first-order optical systems described by the ABCD matrix. Since it was proven in the past that the usual definition for radial polarization is not invariant, such invariance is novel in characterizing the radial and azimuthal polarizations content of optical beams. The possibility of obtaining a pure mode from a given beam using the proposed parameters is discussed. PMID:19183626

  3. EVALUATION OF CARBON BLACK SLURRIES AS CLEAN BURNING FUELS

    EPA Science Inventory

    Experiments were performed to examine the pumpability, atomization and combustion characteristics of slurries made of mixtures of carbon black with No. 2 fuel oil and methanol. Carbon black-No. 2 fuel oil and carbon black-methanol slurries, with carbon black contents of up to 50 ...

  4. Method and apparatus for improved wire saw slurry

    SciTech Connect

    Costantini, Michael A.; Talbott, Jonathan A.; Chandra, Mohan; Prasad, Vishwanath; Caster, Allison; Gupta, Kedar P.; Leyvraz, Philippe

    2000-09-05

    A slurry recycle process for use in free-abrasive machining operations such as for wire saws used in wafer slicing of ingots, where the used slurry is separated into kerf-rich and abrasive-rich components, and the abrasive-rich component is reconstituted into a makeup slurry. During the process, the average particle size of the makeup slurry is controlled by monitoring the condition of the kerf and abrasive components and making necessary adjustments to the separating force and dwell time of the separator apparatus. Related pre-separator and post separator treatments, and feedback of one or the other separator slurry output components for mixing with incoming used slurry and recirculation through the separator, provide further effectiveness and additional control points in the process. The kerf-rich component is eventually or continually removed; the abrasive-rich component is reconstituted into a makeup slurry with a controlled, average particle size such that the products of the free-abrasive machining method using the recycled slurry process of the invention are of consistent high quality with less TTV deviation from cycle to cycle for a prolonged period or series of machining operations.

  5. Rheological Modifier Testing with DWPF Process Slurries

    SciTech Connect

    MICHAEL, STONE

    2004-02-01

    Rheological modification agents were tested on simulated SRAT and SME products to determine if a suitable agent could be found for the DWPF process slurries. The agents tested were dispersants that lower the rheological properties of slurries by preventing agglomerization. Dolapix CE64, an ethylene glycol, and Disperse-Ayd W28, a polyacrylate, were the most effective dispersants tested. Further evaluation and testing should be performed on Dolapix CE64 and Disperse-Ayd W28 to determine if implementation is possible in DWPF. The initial phase of future work will include optimization of the rheology modifier by the Illinois Institute of Technology (IIT) and development of a maximum concentration limit for the rheology modifiers. IIT has been commissioned to evaluate the properties of these chemicals to determine if the chemical makeup can be optimized to enhance the properties of these modifiers. An initial concentration limit based upon the DWPF flammability limit and other constraints should be calculated to determine the potential downstream impacts.

  6. Effective Compressibility of a Bubbly Slurry.

    PubMed

    Kam, S. I.; Gauglitz, P. A.; Rossen, W. R.

    2001-09-01

    The goal of this study is to fit model parameters to changes in waste level in response to barometric pressure changes in underground storage tanks at the Hanford Site. This waste compressibility is a measure of the quantity of gas, typically hydrogen and other flammable gases, that can pose a safety hazard, retained in the waste. A one-dimensional biconical-pore-network model for compressibility of a bubbly slurry is presented in a companion paper. Fitting these results to actual waste level changes in the tanks implies that bubbles in the slurry layer are long and the ratio of pore-body radius to pore-throat radius is close to 1; unfortunately, compressibility can not be quantified unambiguously from the data without additional information on pore geometry. Therefore, determining the quantity of gas in the tanks requires more than just waste-level data. The non-uniqueness of the fit is also found with two other simple models: a capillary-tube model with contact angle hysteresis and a spherical-pore model. Copyright 2001 Academic Press. PMID:11502128

  7. Hydrodynamic models for slurry bubble column reactors

    SciTech Connect

    Dimitri Gidaspow

    1996-10-01

    The objective of this investigation is to convert learning gas-solid-liquid fluidization model into a predictive design model. The IIT hydrodynamic model computers the phase velocities and the volume fi-actions of gas, liquid and particulate phases. Model verification involves a comparison of these computed velocities and volume fractions to experimental values. As promised in the SIXTH TECHNICAL PROGRESS REPORT, January 1996, this report presents measurements of radial distribution function for 450 micron glass particles in liquid-solid fluidized bed. The report is in the form of a preliminary paper. The authors need the radial distribution function to compute the viscosity and the equation of state for particles. The principal results are as follows: (1) The measured radial distribution function, g{sub 0}, is a monotonic function of the solid volume fraction. The values of the radial distribution function g{sub 0} are in the range of the predictions from Bagnold equation and Carnahan and Starling equation. (2) The position of the first peak of the radial distribution function does not lie at r = d at contact (d is particle diameter). This differs from the predications from the hard sphere model and the measurements in the gas-solid system (Gidaspow and Huilin, 1996). This is due to a liquid film lubrication effect in the liquid-solid system.

  8. COMPUTATIONAL AND EXPERIMENTAL MODELING OF SLURRY BUBBLE COLUMN REACTORS

    SciTech Connect

    Paul Lam; Dimitri Gidaspow

    2000-09-01

    The objective if this study was to develop a predictive experimentally verified computational fluid dynamics (CFD) model for gas-liquid-solid flow. A three dimensional transient computer code for the coupled Navier-Stokes equations for each phase was developed. The principal input into the model is the viscosity of the particulate phase which was determined from a measurement of the random kinetic energy of the 800 micron glass beads and a Brookfield viscometer. The computed time averaged particle velocities and concentrations agree with PIV measurements of velocities and concentrations, obtained using a combination of gamma-ray and X-ray densitometers, in a slurry bubble column, operated in the bubbly-coalesced fluidization regime with continuous flow of water. Both the experiment and the simulation show a down-flow of particles in the center of the column and up-flow near the walls and nearly uniform particle concentration. Normal and shear Reynolds stresses were constructed from the computed instantaneous particle velocities. The PIV measurement and the simulation produced instantaneous particle velocities. The PIV measurement and the simulation produced similar nearly flat horizontal profiles of turbulent kinetic energy of particles. This phase of the work was presented at the Chemical Reaction Engineering VIII: Computational Fluid Dynamics, August 6-11, 2000 in Quebec City, Canada. To understand turbulence in risers, measurements were done in the IIT riser with 530 micron glass beads using a PIV technique. The results together with simulations will be presented at the annual meeting of AIChE in November 2000.

  9. Chemists report slurry breakthroughs for syngas-to-alcohol process

    SciTech Connect

    Rotman, D.

    1996-04-24

    Scientists at North Carolina State University (Raleigh) report that they have developed an alcohol synthesis process that uses a high-temperature slurry reactor with a conventional zinc chromite methanol catalyst. The scientists say it is the first time zinc-chromite catalysts have been used in slurry reactors at temperatures as high as 375 C. They add that it could lead to a synthesis gas (syngas)-based route to higher alcohols and to broader commercial applications for slurry reactors. Slurry reactors typically operate at less than 300 C, limiting applications for many high-volume industrial applications. By extending the temperature 100 C, says George Roberts, a chemist at North Carolina State, the work could {open_quotes}open up chemistry never run in slurry reactors before.{close_quotes} Roberts points to potential for use in partial oxidation reactions and synthesis routes involving formaldehyde.

  10. SRC-water slurry rheology. Final technical report

    SciTech Connect

    Tewari, K.C.

    1984-02-01

    SRC-water slurries exhibit properties that qualify them for use as fuel in conventional oil-fired combustion facilities. However, to date, the slurries tested have shown storage instability, which requires constant agitation and recirculation to avoid sedimentation in the storage tanks. High viscosities of the material being evaluated hampered the test performance. A program was instituted to better understand the variables responsible for viscosity and static stability of these slurries. Effective additives and concentrations were determined. This report presents laboratory data demonstrating that solid concentration, particle size distribution, additive concentration, and slurry preparation technique influence the viscosity and stability characteristics of an SRC-water slurry. 7 references, 12 figures, 11 tables.

  11. Entropy generation of radial rotation convective channels

    NASA Astrophysics Data System (ADS)

    Alić, Fikret

    2012-03-01

    The exchange of heat between two fluids is established by radial rotating pipe or a channel. The hotter fluid flows through the pipe, while the cold fluid is ambient air. Total length of pipe is made up of multiple sections of different shape and position in relation to the common axis of rotation. In such heat exchanger the hydraulic and thermal irreversibility of the hotter and colder fluid occur. Therefore, the total entropy generated within the radial rotating pipe consists of the total entropy of hotter and colder fluid, taking into account all the hydraulic and thermal irreversibility of both fluids. Finding a mathematical model of the total generated entropy is based on coupled mathematical expressions that combine hydraulic and thermal effects of both fluids with the complex geometry of the radial rotating pipe. Mathematical model follows the each section of the pipe and establishes the function between the sections, so the total generated entropy is different from section to section of the pipe. In one section of the pipe thermal irreversibility may dominate over the hydraulic irreversibility, while in another section of the pipe the situation may be reverse. In this paper, continuous analytic functions that connect sections of pipe in geometric meaning are associated with functions that describe the thermo-hydraulic effects of hotter and colder fluid. In this way, the total generated entropy of the radial rotating pipe is a continuous analytic function of any complex geometry of the rotating pipe. The above method of establishing a relationship between the continuous function of entropy with the complex geometry of the rotating pipe enables indirect monitoring of unnecessary hydraulic and thermal losses of both fluids. Therefore, continuous analytic functions of generated entropy enable analysis of hydraulic and thermal irreversibility of individual sections of pipe, as well as the possibility of improving the thermal-hydraulic performance of the rotating

  12. Deposition Velocities of Newtonian and Non-Newtonian Slurries in Pipelines

    SciTech Connect

    Poloski, Adam P.; Adkins, Harold E.; Abrefah, John; Casella, Andrew M.; Hohimer, Ryan E.; Nigl, Franz; Minette, Michael J.; Toth, James J.; Tingey, Joel M.; Yokuda, Satoru T.

    2009-03-01

    correlation used in the WTP design guide has been shown to be inaccurate for Hanford waste feed materials. The use of the Thomas (1979) correlation in the design guide is not conservative—In cases where 100% of the particles are smaller than 74 μm or particles are considered to be homogeneous due to yield stress forces suspending the particles the homogeneous fraction of the slurry can be set to 100%. In such cases, the predicted critical velocity based on the conservative Oroskar and Turian (1980) correlation is reduced to zero and the design guide returns a value from the Thomas (1979) correlation. The measured data in this report show that the Thomas (1979) correlation predictions often fall below that measured experimental values. A non-Newtonian deposition velocity design guide should be developed for the WTP— Since the WTP design guide is limited to Newtonian fluids and the WTP expects to process large quantities of such materials, the existing design guide should be modified address such systems. A central experimental finding of this testing is that the flow velocity required to reach turbulent flow increases with slurry rheological properties due to viscous forces dampening the formation of turbulent eddies. The flow becomes dominated by viscous forces rather than turbulent eddies. Since the turbulent eddies necessary for particle transport are not present, the particles will settle when crossing this boundary called the transitional deposition boundary. This deposition mechanism should be expected and designed for in the WTP.

  13. Coplanar Waveguide Radial Line Stub

    NASA Technical Reports Server (NTRS)

    Simons, R. N.; Taub, S. R.

    1993-01-01

    A coplanar waveguide radial line stub resonator is experimentally characterized with respect to stub radius, sectoral angle, substrate thickness, and relative dielectric constant. A simple closed-form design equation which predicts the resonance radius of the stub is presented.

  14. Guar gum solutions for improved delivery of iron particles in porous media (part 2): iron transport tests and modeling in radial geometry.

    PubMed

    Tosco, Tiziana; Gastone, Francesca; Sethi, Rajandrea

    2014-10-01

    In the present work column transport tests were performed in order to study the mobility of guar-gum suspensions of microscale zero-valent iron particles (MZVI) in porous media. The results were analyzed with the purpose of implementing a radial model for the design of full scale interventions. The transport tests were performed using several concentrations of shear thinning guar gum solutions as stabilizer (1.5, 3 and 4g/l) and applying different flow rates (Darcy velocity in the range 1·10(-4) to 2·10(-3)m/s), representative of different distances from the injection point in the radial domain. Empirical relationships, expressing the dependence of the deposition and release parameters on the flow velocity, were derived by inverse fitting of the column transport tests using a modified version of E-MNM1D (Tosco and Sethi, 2010) and the user interface MNMs (www.polito.it/groundwater/software). They were used to develop a comprehensive transport model of MZVI suspensions in radial coordinates, called E-MNM1R, which takes into account the non Newtonian (shear thinning) rheological properties of the dispersant fluid and the porous medium clogging associated with filtration and sedimentation in the porous medium of both MZVI and guar gum residual undissolved particles. The radial model was run in forward mode to simulate the injection of MZVI dispersed in guar gum in conditions similar to those applied in the column transport tests. In a second stage, we demonstrated how the model can be used as a valid tool for the design and the optimization of a full scale intervention. The simulation results indicated that several concurrent aspects are to be taken into account for the design of a successful delivery of MZVI/guar gum slurries via permeation injection, and a compromise is necessary between maximizing the radius of influence of the injection and minimizing the injection pressure, to guarantee a sufficiently homogeneous distribution of the particles around the

  15. Guar gum solutions for improved delivery of iron particles in porous media (Part 2): Iron transport tests and modeling in radial geometry

    NASA Astrophysics Data System (ADS)

    Tosco, Tiziana; Gastone, Francesca; Sethi, Rajandrea

    2014-10-01

    In the present work column transport tests were performed in order to study the mobility of guar-gum suspensions of microscale zero-valent iron particles (MZVI) in porous media. The results were analyzed with the purpose of implementing a radial model for the design of full scale interventions. The transport tests were performed using several concentrations of shear thinning guar gum solutions as stabilizer (1.5, 3 and 4 g/l) and applying different flow rates (Darcy velocity in the range 1 · 10- 4 to 2 · 10- 3 m/s), representative of different distances from the injection point in the radial domain. Empirical relationships, expressing the dependence of the deposition and release parameters on the flow velocity, were derived by inverse fitting of the column transport tests using a modified version of E-MNM1D (Tosco and Sethi, 2010) and the user interface MNMs (www.polito.it/groundwater/software). They were used to develop a comprehensive transport model of MZVI suspensions in radial coordinates, called E-MNM1R, which takes into account the non Newtonian (shear thinning) rheological properties of the dispersant fluid and the porous medium clogging associated with filtration and sedimentation in the porous medium of both MZVI and guar gum residual undissolved particles. The radial model was run in forward mode to simulate the injection of MZVI dispersed in guar gum in conditions similar to those applied in the column transport tests. In a second stage, we demonstrated how the model can be used as a valid tool for the design and the optimization of a full scale intervention. The simulation results indicated that several concurrent aspects are to be taken into account for the design of a successful delivery of MZVI/guar gum slurries via permeation injection, and a compromise is necessary between maximizing the radius of influence of the injection and minimizing the injection pressure, to guarantee a sufficiently homogeneous distribution of the particles around the

  16. KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYSTHESIS

    SciTech Connect

    Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski

    2005-09-29

    This report covers the third year of this research grant under the University Coal Research program. The overall objective of this project is to develop a comprehensive kinetic model for slurry phase Fischer-Tropsch synthesis (FTS) on iron catalysts. This model will be validated with experimental data obtained in a stirred tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict molar flow rates and concentrations of all reactants and major product species (H{sub 2}O, CO{sub 2}, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the reporting period we utilized experimental data from the STSR, that were obtained during the first two years of the project, to perform vapor-liquid equilibrium (VLE) calculations and estimate kinetic parameters. We used a modified Peng-Robinson (PR) equation of state (EOS) with estimated values of binary interaction coefficients for the VLE calculations. Calculated vapor phase compositions were in excellent agreement with experimental values from the STSR under reaction conditions. Occasional discrepancies (for some of the experimental data) between calculated and experimental values of the liquid phase composition were ascribed to experimental errors. The VLE calculations show that the vapor and the liquid are in thermodynamic equilibrium under reaction conditions. Also, we have successfully applied the Levenberg-Marquardt method (Marquardt, 1963) to estimate parameters of a kinetic model proposed earlier by Lox and Froment (1993b) for FTS on an iron catalyst. This kinetic model is well suited for initial studies where the main goal is to learn techniques for parameter estimation and statistical analysis of estimated values of model parameters. It predicts that the chain growth parameter ({alpha}) and olefin to paraffin ratio are independent of carbon number, whereas our experimental data show that they vary with the carbon number

  17. Heat transfer and bubble dynamics in slurry bubble columns for Fischer-Tropsch clean alternative energy

    NASA Astrophysics Data System (ADS)

    Wu, Chengtian

    With the increasing demand for alternative energy resources, the Fischer-Tropsch (FT) process that converts synthesis gas into clean liquid fuels has attracted more interest from the industry. Slurry bubble columns are the most promising reactors for FT synthesis due to their advantages over other reactors. Successful operation, design, and scale-up of such reactors require detailed knowledge of hydrodynamics, bubble dynamics, and transport characteristics. However, most previous studies have been conducted at ambient pressure or covered only low superficial gas velocities. The objectives of this study were to experimentally investigate the heat transfer coefficient and bubble dynamics in slurry bubble columns at conditions that can mimic FT conditions. The air-C9C 11-FT catalysts/glass beads systems were selected to mimic the physical properties of the gas, liquid, and solid phases at commercial FT operating conditions. A heat transfer coefficient measurement technique was developed, and for the first time, this technique was applied in a pilot scale (6-inch diameter) high pressure slurry bubble column. The effects of superficial gas velocity, pressure, solids loading, and liquid properties on the heat transfer coefficients were investigated. Since the heat transfer coefficient can be affected by the bubble properties (Kumar et al., 1992), in this work bubble dynamics (local gas holdup, bubble chord length, apparent bubble frequency, specific interfacial area, and bubble velocity) were studied using the improved four-point optical probe technique (Xue et al., 2003; Xue, 2004). Because the four-point optical technique had only been successfully applied in a churn turbulent flow bubble column (Xue, 2004), this technique was first assessed in a small scale slurry bubble column in this study. Then the bubble dynamics were studied at the same conditions as the heat transfer coefficient investigation in the same pilot scale column. The results from four-point probe

  18. Improved Fischer-Tropsch Slurry Reactors

    SciTech Connect

    Andrew Lucero

    2009-03-20

    The conversion of synthesis gas to hydrocarbons or alcohols involves highly exothermic reactions. Temperature control is a critical issue in these reactors for a number of reasons. Runaway reactions can be a serious safety issue, even raising the possibility of an explosion. Catalyst deactivation rates tend to increase with temperature, particularly of there are hot spots in the reactor. For alcohol synthesis, temperature control is essential because it has a large effect on the selectivity of the catalysts toward desired products. For example, for molybdenum disulfide catalysts unwanted side products such as methane, ethane, and propane are produced in much greater quantities if the temperature increases outside an ideal range. Slurry reactors are widely regarded as an efficient design for these reactions. In a slurry reactor a solid catalyst is suspended in an inert hydrocarbon liquid, synthesis gas is sparged into the bottom of the reactor, un-reacted synthesis gas and light boiling range products are removed as a gas stream, and heavy boiling range products are removed as a liquid stream. This configuration has several positive effects for synthesis gas reactions including: essentially isothermal operation, small catalyst particles to reduce heat and mass transfer effects, capability to remove heat rapidly through liquid vaporization, and improved flexibility on catalyst design through physical mixtures in addition to use of compositions that cannot be pelletized. Disadvantages include additional mass transfer resistance, potential for significant back-mixing on both the liquid and gas phases, and bubble coalescence. In 2001 a multiyear project was proposed to develop improved FT slurry reactors. The planned focus of the work was to improve the reactors by improving mass transfer while considering heat transfer issues. During the first year of the project the work was started and several concepts were developed to prepare for bench-scale testing. Power

  19. Some observations of the effects of radial distortions on performance of a transonic rotating blade row

    NASA Technical Reports Server (NTRS)

    Sandercock, D. M.; Sanger, N. L.

    1974-01-01

    A single rotating blade row was tested with two magnitudes of tip radial distortion and two magnitudes of hub radial distortion imposed on the inlet flow. The rotor was about 50 centimeters (20 in.) in diameter and had a design operating tip speed of approximately 420 meters per second (1380 ft/sec). Overall performance at 60, 80, and 100 percent of equivalent design speed generally showed a decrease (compared to undistorted flow) in rotor stall margin with tip radial distortion but no change, or a slight increase, in rotor stall margin with hub radial distortion. At design speed there was a decrease in rotor overall total pressure ratio and choke flow with all inlet flow distortions. Radial distributions of blade element parameters are presented for selected operating conditions at design speed.

  20. ADVANCED DIAGNOSTIC TECHNIQUES FOR THREE-PHASE SLURRY BUBBLE COLUMN REACTORS (SBCR)

    SciTech Connect

    M.H. Al-Dahhan; M.P. Dudukovic; L.S. Fan

    2001-07-25

    This report summarizes the accomplishment made during the second year of this cooperative research effort between Washington University, Ohio State University and Air Products and Chemicals. The technical difficulties that were encountered in implementing Computer Automated Radioactive Particle Tracking (CARPT) in high pressure SBCR have been successfully resolved. New strategies for data acquisition and calibration procedure have been implemented. These have been performed as a part of other projects supported by Industrial Consortium and DOE via contract DE-2295PC95051 which are executed in parallel with this grant. CARPT and Computed Tomography (CT) experiments have been performed using air-water-glass beads in 6 inch high pressure stainless steel slurry bubble column reactor at selected conditions. Data processing of this work is in progress. The overall gas holdup and the hydrodynamic parameters are measured by Laser Doppler Anemometry (LDA) in 2 inch slurry bubble column using Norpar 15 that mimic at room temperature the Fischer Tropsch wax at FT reaction conditions of high pressure and temperature. To improve the design and scale-up of bubble column, new correlations have been developed to predict the radial gas holdup and the time averaged axial liquid recirculation velocity profiles in bubble columns.

  1. Testing of In-Line Slurry Monitors and Pulsair Mixers with Radioactive Slurries

    SciTech Connect

    Hylton, T.D.; Bayne, C.K.

    1999-08-01

    Three in-line slurry monitoring instruments were demonstrated, tested, and evaluated for their capability to determine the transport properties of radioactive slurries. The instruments included the Endress + Hauser Promass 63M Coriolis meter for measuring density, the Lasentec M600P for measuring particle size distribution, and a prototype ultrasonic monitor that was developed by Argonne National Laboratory for measuring suspended solids concentration. In addition, the power consumption of the recirculation pump was monitored to determine whether this parameter could be used as a tool for in-line slurry monitoring. The Promass 63M and the M600P were also evaluated as potential indicators of suspended solids concentration. In order to use the Promass 63M as a suspended solids monitor, the densities of the fluid phase and the dry solid particle phase must be known. In addition, the fluid phase density and the dry solids density must remain constant, as any change will affect the correlation between the slurry density and the suspended solids concentration. For the M600P, the particle size distribution would need to remain relatively constant. These instruments were demonstrated and tested at the Gunite and Associated Tanks Remediation Project at the Oak Ridge National Laboratory. The testing of the instruments was conducted in parallel with the testing of a Pulsair mixing system, which was used to mix the contents of the selected tank. A total of six tests were performed. A submersible pump was positioned at two depths, while the Pulsair system was operated at three mixing rates.

  2. Erosion Evaluation of a Slurry Mixer Tank with Computational Fluid Dynamics Methods

    SciTech Connect

    Lee, S

    2006-03-22

    This paper discusses the use of computational fluid dynamics (CFD) methods to understand and characterize erosion of the floor and internal structures in the slurry mixing vessels in the Defense Waste Processing Facility. An initial literature survey helped identify the principal drivers of erosion for a solids laden fluid: the solids content of the working fluid, the regions of recirculation and particle impact with the walls, and the regions of high wall shear. A series of CFD analyses was performed to characterize slurry-flow profiles, wall shear, and particle impingement distributions in key components such as coil restraints and the vessel floor. The calculations showed that the primary locations of high erosion resulting from abrasion were at the leading edge of the coil guide, the tank floor below the insert plate of the coil guide support, and the upstream lead-in plate. These modeling results based on the calculated high shear regions were in excellent agreement with the observed erosion sites in both location and the degree of erosion. Loss of the leading edge of the coil guide due to the erosion damage during the slurry mixing operation did not affect the erosion patterns on the tank floor. Calculations for a lower impeller speed showed similar erosion patterns but significantly reduced wall shear stresses.

  3. Erosion Evaluations of Slurry Mixer Tank With Computational Fluid Dynamics Methods

    SciTech Connect

    Lee, Si Y.; Dimenna, Richard A.; Taylor, Glenn A.

    2006-07-01

    This paper discusses the use of computational fluid dynamics (CFD) methods to understand and characterize erosion of the floor and internal structures in the slurry mixing vessels in the Defense Waste Processing Facility. An initial literature survey helped identify the principal drivers of erosion for a solids laden fluid: the solids content of the working fluid, the regions of recirculation and particle impact with the walls, and the regions of high wall shear. A series of CFD analyses was performed to characterize slurry-flow profiles, wall shear, and particle impingement distributions in key components such as coil restraints and the vessel floor. The calculations showed that the primary locations of high erosion resulting from abrasion were at the leading edge of the coil guide, the tank floor below the insert plate of the coil guide support, and the upstream lead-in plate. These modeling results based on the calculated high shear regions were in excellent agreement with the observed erosion sites in both location and the degree of erosion. Loss of the leading edge of the coil guide due to the erosion damage during the slurry mixing operation did not affect the erosion patterns on the tank floor. Calculations for a lower impeller speed showed similar erosion patterns but significantly reduced wall shear stresses. (authors)

  4. Hydrodynamics of the three-phase slurry Fischer-Tropsch bubble column reactors

    SciTech Connect

    Bukur, D.B.; Daly, J.G.; Patel, S.A.

    1990-09-01

    This report describes results of a study on hydrodynamics of three-phase bubble columns for Fischer-Tropsch synthesis. Experiments were conducted in two stainless bubble columns of 0.05 m and 0.21 m in diameter and 3 m tall, at 265{degrees}C and atmospheric pressure using nitrogen gas and two types of liquid medium (hydrotreated reactor wax designated FT-300, and raw reactor wax from fixed bed rectors at SASOL). The effects of solids types (iron oxide and silica), concentration (0--30 wt %), size (0--5 {mu}m and 20--44 {mu}m), slurry (liquid) velocity (up to 0.02 m/s) on the gas holdup and axial solids concentration profiles, were investigated. Phase volume fractions were determined using conventional (differential pressure measurements together with determination of slurry concentration along the column) and novel (dual energy nuclear density gauge) experimental techniques. Bubble size distribution and the Sauter mean bubble diameter were obtained using the dynamic gas disengagement (DGD) method. Flow regime transitions in both columns were determined using statistical analysis of both pressure and density fluctuations. Correlations for prediction of gas holdups and axial solids dispersion coefficient have been developed from experimental data obtained in this study. Data needed for calculation of the gas-liquid interfacial area (average gas holdup and Sauter mean bubble diameter) have been presented and can be used to estimate the mass transfer rate in slurry bubble column reactors. 105 refs., 19 figs., 38 tabs.

  5. PCB dechlorination in anaerobic soil slurry reactors

    SciTech Connect

    Klasson, K.T.; Evans, B.S.

    1993-11-29

    Many industrial locations, including the US Department of Energy`s, have identified needs for treatment of polychlorinated biphenyl (PCB) wastes and remediation of PCB-contaminated sites. Biodegradation of PCBs is a potentially effective technology for the treatment of PCB-contaminated soils and sludges, including mixed wastes; however, a practical remediation technology has not yet been demonstrated. In laboratory experiments, soil slurry bioreactors inoculated with microorganisms extracted from PCB-contaminated sediments from the Hudson River have been used to obtain anaerobic dechlorination of PCBS. The onset of dechlorination activity can be accelerated by addition of nutritional amendments and inducers. After 15 weeks of incubation with PCB-contaminated soil and nutrient solution, dechlorination has been observed under several working conditions. The best results show that the average chlorine content steadily dropped from 4.3 to 3.5 chlorines per biphenyl over a 15-week period.

  6. Desulfurization from Bauxite Water Slurry (BWS) Electrolysis

    NASA Astrophysics Data System (ADS)

    Gong, Xuzhong; Ge, Lan; Wang, Zhi; Zhuang, Siyuan; Wang, Yuhua; Ren, Lihui; Wang, Mingyong

    2016-02-01

    Feasibility of high-sulfur bauxite electrolysis desulfurization was examined using the electrochemical characterization, XRD, DTA, and FTIR. The cyclic voltammetry curves indicated that bauxite water slurry (BWS) electrolysis in NaOH system was controlled by diffusion. Additionally, the desulfurization effect of NaCl as the electrolyte was significantly better than that of NaOH as an electrolyte. As the stirring rate increased, the desulfurization ratio in NaCl system was not increased obviously, while the desulfurization ratio in NaOH system increased significantly, indicating further that electrolysis desulfurization in NaOH solution was controlled by diffusion. According to XRD, DTA, and FTIR analysis, the characteristic peaks of sulfur-containing phase in bauxite after electrolysis weakened or disappeared, indicating that the pyrite in bauxite was removed from electrolysis. Finally, the electrolytic desulfurization technology of bauxite was proposed based on the characteristics of BWS electrolysis.

  7. Ice slurry cooling development and field testing

    SciTech Connect

    Kasza, K.E.; Hietala, J.; Wendland, R.D.; Collins, F.

    1992-07-01

    A new advanced cooling technology collaborative program is underway involving Argonne National Laboratory (ANL), Northern States Power (NSP) and the Electric Power Research Institute (EPRI). The program will conduct field tests of an ice slurry distributed load network cooling concept at a Northern States Power utility service center to further develop and prove the technology and to facilitate technology transfer to the private sector. The program will further develop at Argonne National Laboratory through laboratory research key components of hardware needed in the field testing and develop an engineering data base needed to support the implementation of the technology. This program will sharply focus and culminate research and development funded by both the US Department of Energy and the Electric Power Research Institute on advanced cooling and load management technology over the last several years.

  8. Ice slurry cooling development and field testing

    SciTech Connect

    Kasza, K.E. ); Hietala, J. ); Wendland, R.D. ); Collins, F. )

    1992-01-01

    A new advanced cooling technology collaborative program is underway involving Argonne National Laboratory (ANL), Northern States Power (NSP) and the Electric Power Research Institute (EPRI). The program will conduct field tests of an ice slurry distributed load network cooling concept at a Northern States Power utility service center to further develop and prove the technology and to facilitate technology transfer to the private sector. The program will further develop at Argonne National Laboratory through laboratory research key components of hardware needed in the field testing and develop an engineering data base needed to support the implementation of the technology. This program will sharply focus and culminate research and development funded by both the US Department of Energy and the Electric Power Research Institute on advanced cooling and load management technology over the last several years.

  9. Mechanics of Bubbles in Sludges and Slurries

    SciTech Connect

    Gauglitz, Phillip A; Terrones, Guillermo; Rossen, William R

    2001-12-31

    The Hanford Site has 177 underground waste storage tanks that are known to retain and release bubbles composed of flammable gases. Characterizing and understanding the behavior of these bubbles is important for the safety issues associated with the flammable gases for both ongoing waste storage and future waste-retrieval operations. The retained bubbles are known to respond to small barometric pressure changes, though in a complex manner with unusual hysteresis occurring in some tanks in the relationship between bubble volume and pressure, or V-P hysteresis. With careful analysis, information on the volume of retained gas and the interactions of the waste and the bubbles can be determined. The overall objective of this study is to create a better understanding of the mechanics of bubbles retained in high-level waste sludges and slurries. Significant advancements have been made in all the major areas of basic theoretical and experimental method development.

  10. High power radial klystron oscillator

    SciTech Connect

    Arman, M.J.

    1995-11-01

    The advantages of the radial klystron amplifier over the conventional klystron amplifier have been reported by Arman et al. Briefly, the radial structure of this design allows for much smaller impedances and thus higher power, the beam-cavity coupling is stronger because the beam travels inside the cavity, and the source is much more compact because there is no need for external magnetic fields. Here the author reports on possible advantages of the radial klystron oscillator over the radial klystron amplifier. The amplifying nature of certain HPM sources is often mandated by the requirement for synchronization and phase-locking of a number of sources in specific applications. In situations where amplification is solely adhered to for the purpose of achieving higher powers, the oscillator will be a better choice if a mechanism can be found to grow the desired mode at the required frequency. By switching to the oscillator mode there will be no need for priming the cavity or maintaining the phase. This simplifies the design and reduces the operational and maintenance cost of the source. Here he reports that an oscillator version of the radial klystron is possible and in fact more suitable for many applications. The mechanism for exciting and growing the mode will be transit-time effects thus providing all the beneficial features of the transit-time oscillators. The complications due to the presence of thin foils in the radial design still persist and will be dealt with in subsequent works. Numerical simulations using the PIC codes MAGIC and SOS indicate the radial klystron oscillator is a viable and efficient means of rf generation.

  11. Effects of coal slurry on wastewater bacteria and bacteriophage

    SciTech Connect

    Margler, L.W.; Rogozen, M.B.

    1980-01-01

    Coal slurry was only mildly toxic to coliform bacteria, which serve as indicators of pathogenic microorganisms in wastewater, and the fecal streptococci concentration appeared to remain essentially unchanged with respect to the wastewater control. Thus the results do not support the supposition that wastewater would be naturally disinfected in a coal slurry pipeline. On the other hand, at least 99.8% of the E. coli C-specific phage present in the wastewater became noninfective in the coal slurry. Should water-borne pathogenic viruses lose infectivity to a similar extent, use of wastewater as the slurry medium would indeed result in upgrading of the water. Depending on the method of disposing of the slurry wastewater at the terminus of the pipeline, disinfection may be required. The possibility exists that future regulations would require disinfection of viruses in addition to indicator bacteria. Under such regulations, the task of disinfecting the slurry wastewater should be greatly facilitated because viruses are generally more resistent to disinfection than are bacteria. The important question remaining and requiring further study, however, is what effect would coal slurry have on pathogenic enteric viruses.

  12. Toxicity evaluation of pig slurry using luminescent bacteria and zebrafish.

    PubMed

    Chen, Wenyan; Cai, Qiang; Zhao, Yuan; Zheng, Guojuan; Liang, Yuting

    2014-07-01

    Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri), larvae and embryos of zebrafish (Danio rerio) were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC50 for luminescent bacteria and the LC50 for larvae were only 6.81% (v/v) and 1.95% (v/v) respectively, and embryonic development was inhibited at just 1% (v/v). Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR), while the LC50 of larvae was 75.23% (v/v) and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent. PMID:24995598

  13. Toxicity Evaluation of Pig Slurry Using Luminescent Bacteria and Zebrafish

    PubMed Central

    Chen, Wenyan; Cai, Qiang; Zhao, Yuan; Zheng, Guojuan; Liang, Yuting

    2014-01-01

    Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri), larvae and embryos of zebrafish (Danio rerio) were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC50 for luminescent bacteria and the LC50 for larvae were only 6.81% (v/v) and 1.95% (v/v) respectively, and embryonic development was inhibited at just 1% (v/v). Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR), while the LC50 of larvae was 75.23% (v/v) and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent. PMID:24995598

  14. Bio-slurry reaction system and process for hazardous waste treatment

    SciTech Connect

    Castaldi, F.J.

    1993-08-03

    A method is described for improved slurry-phase bioremediation treatment of organic sludge and mixtures of organic sludge and organic-contaminated soils by dissolving the contaminants into an aqueous phase and microbially degrading same; comprising the steps of: (a) forming a high solids slurry of the sludge and soils with water and an active bioslurry consisting of large populations of acclimated hydrocarbon-utilizing bacteria and small amounts of biodegradation residue; the bacteria being selected from the genera Pseudomonas and Acinetobacter, and being capable of producing extracellular long-chain hydrocarbon-emulsifying and hydrocarbon-solubilizing agents for decreasing aqueous surface tension and lowering interfacial tension between oil and water; (b) passing the high solids slurry through a plurality of in-series bioreactors in each of which a low hydraulic shear is maintained to promote the development of a large population of microorganisms that will form flocculent suspensions; the first stage bioreactor in the series being a waste dissolution reactor operated under anoxic conditions to form a stable emulsion through the presence of the hydrocarbon-emulsifying and hydrocarbon-solubilizing agents produced by the bacteria; (c) continuously or semicontinuously flowing the output from the series of bioreactors to a liquid-solids separator to partition the mixed liquor bioslurry from the biodegraded waste residue; (d) returning the mixed liquor bioslurry containing small amounts of biodegradation residue to the slurry of step (a) for recycling; and (e) recirculating off-gas components from the system including one or more members of the group consisting of benzene, toluene, xylenes, and naphthalene back to one or more of the bioreactors, to return high volatility toxic constituents for increased microbial degradation and control of volatile toxic constituents emissions from the process.

  15. Multiple model approach to evaluation of accelerated carbonation for steelmaking slag in a slurry reactor.

    PubMed

    Pan, Shu-Yuan; Liu, Hsing-Lu; Chang, E-E; Kim, Hyunook; Chen, Yi-Hung; Chiang, Pen-Chi

    2016-07-01

    Basic oxygen furnace slag (BOFS) exhibits highly alkaline properties due to its high calcium content, which is beneficial to carbonation reaction. In this study, accelerated carbonation of BOFS was evaluated under different reaction times, temperatures, and liquid-to-solid (L/S) ratios in a slurry reactor. CO2 mass balance within the slurry reactor was carried out to validate the technical feasibility of fixing gaseous CO2 into solid precipitates. After that, a multiple model approach, i.e., theoretical kinetics and empirical surface model, for carbonation reaction was presented to determine the maximal carbonation conversion of BOFS in a slurry reactor. On one hand, the reaction kinetics of BOFS carbonation was evaluated by the shrinking core model (SCM). Calcite (CaCO3) was identified as a reaction product through the scanning electronic microscopy and X-ray diffraction analyses, which provided the rationale of applying the SCM in this study. The rate-limiting step of carbonation was found to be ash-diffusion controlled, and the effective diffusivity for carbonation of BOFS in a slurry reactor were determined accordingly. On the other hand, the carbonation conversion of BOFS was predicted by the response surface methodology (RSM) via a nonlinear mathematical programming. According to the experimental data, the highest carbonation conversion of BOFS achieved was 57% under an L/S ratio of 20 mL g(-1), a CO2 flow rate of 0.1 L min(-1), and a pressure of 101.3 kPa at 50 °C for 120 min. Furthermore, the applications and limitations of SCM and RSM were examined and exemplified by the carbonation of steelmaking slags. PMID:27038901

  16. ENGINEERING DEVELOPMENT OF SLURRY BUBBLE COLUMN REACTOR (SBCR) TECHNOLOGY

    SciTech Connect

    Bernard A. Toseland

    2001-03-31

    The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity, (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions, and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors. Washington University's work for the quarter involved the study of the dynamic simulations of bubble columns in three dimensions. Work was also done in dynamic simulations of two-phase transient flow using CFDLIB. Ohio State measured the axial dispersion coefficients of the liquid phase. The steady-state thermal dispersion method was used to obtain the measurements. Iowa State followed the last quarter's work by using CFDLIB to simulate conditions described in the literature, with the objective of validating the simulation result. The group's work also led to a determination of the adequacy of periodic boundary conditions in representing small columns.

  17. Development of Syringe/Bottle Hybrids for Sampling Slurries

    SciTech Connect

    Coleman, C.J.

    1998-01-08

    A convenient and effective sample bottle system based on simple modifications of disposable plastic syringes and bottles has been devised and tested for slurry samples. Syringe/ bottle hybrids (hereafter referred to as syringe bottles) have the convenience of regular flat-bottom bottles with screw cap closures. In addition, the syringe imparts a sliding and adjustable bottom to the bottle that forces the entire contents from the bottle. The system was designed especially to collect samples for high temperature work-ups of DWPF slurry samples. The syringe bottles together with fixed-bottom sample vial inserts would provide the DWPF with convenient and reliable methods for dealing with slurry samples.

  18. Preparing polymeric matrix composites using an aqueous slurry technique

    NASA Technical Reports Server (NTRS)

    Johnston, Norman J. (Inventor); Towell, Timothy W. (Inventor)

    1993-01-01

    An aqueous process was developed to prepare a consolidated composite laminate from an aqueous slurry. An aqueous poly(amic acid) surfactant solution was prepared by dissolving a poly(amic acid) powder in an aqueous ammonia solution. A polymeric powder was added to this solution to form a slurry. The slurry was deposited on carbon fiber to form a prepreg which was dried and stacked to form a composite laminate. The composite laminate was consolidated using pressure and was heated to form the polymeric matrix. The resulting composite laminate exhibited high fracture toughness and excellent consolidation.

  19. Use of slurry reactors in converting syngas to chemicals

    SciTech Connect

    Brown, D.M.; Waller, F.J.

    1996-10-01

    The excellent heat management offered by slurry reactors favors their use in many syngas conversion processes. Since 1981 Air Products has been developing a Slurry Phase Methanol process which is superior in performance to conventional methanol technologies, particular for carbon-rich sources of syngas. The first commercial plant using their process is under construction and its genesis is described in this paper. Extension of the approach to the synthesis of higher alcohols, acetates and ethers is also covered. An outline is given of remaining specific catalyst challenges and opportunities available for new catalysts in the slurry environment.

  20. [Influence of bioleaching on dewaterability of cattle biogas slurry].

    PubMed

    Zhou, Jun; Zhou, Li-Xiang; Liu, Fen-Wu; Ren, Yun; Wang, Dian-Zhan

    2011-11-01

    The dewaterability of cattle biogas slurry facilitated by bioleaching was investigated through batch experiments with co-inoculation of different Acidophilic thiobacilli (Acidithiobacillus thiooxidans TS6 or Acidithiobacillus ferrooxidans LX5). The experiment was set the following 5 treatments: (1) original biogas slurry (CK), (2) 4 g x L(-1) Fe(2+) (uninoculation), (3)2 g x L(-1) S(0) + 25 mL A. t, (4) 4 g x L(-1) Fe(2+) + 25 mL A. f and (5) 2 g x L(-1) S(0) + 4 g x L(-1) Fe(2+) + 12.5 mL A. t + 12.5 mL A. f. During bioleaching, dynamic changes of pH, ORP, Fe(2+), F(3+), total Fe, the settleability, the turbidity of the supernatant after settling for 12 h, and the dewaterability (expressed as specific resistance to filtration gamma or capillary suction time, CST) of biogas slurry were monitored. Results show that specific resistance gamma and CST of bioleached biogas slurry are reduced drastically for the treatments of original biogas slurry spiked with only Fe(2+), the treatment of original biogas slurry co-spiked with Fe(2+) and Acidithiobacillus ferrooxidans LX5, and the treatment of original biogas slurry co-spiked with Fe(2+), S(0) and two Acidophilic thiobacilli. Taking the dewaterability, settleability, the turbidity of the supernatant fluid after settle 12 h and economical cost into account, the treatment of original biogas slurry co-spiked with Fe(2+) and Acidithiobacillus ferrooxidans LX5 is the most suitable pattern for cattle biogas slurry bioleaching. After bioleaching, 1.14% of organic matter, 0.09% of N, 0.05% of P, and 0.1% of K are lost in the bioleaching process, but it don't affect its fertilizer efficiency. Meanwhile, the 63.2% of Cu and 91.3% of Zn are removed from the biogas slurry, and elimination efficiencies of total coliforms in bioleached slurry exceed 99%. This study might provide a new approach for treatment and disposal of biogas slurry. PMID:22295641

  1. Roles of additives and surface control in slurry atomization

    SciTech Connect

    Tsai, S.C.

    1990-07-10

    Airblast atomization of micronized coal water slurry is carried out using twin-fluid jet atomizers of various distributor designs. Drop size and size distribution are measured using the laser diffraction technique. We found that the atomized drop sizes of micronized coal water slurries substantially decrease as the atomizing air pressure exceeds a threshold value. We also found that the atomized drop size, represented by the mass median diameter (MMD) can be described by the wave mechanism-based models in terms of three non-dimensional groups, namely, slurry-to-air mass ratio, the Weber number, and the Ohnesorge number. 11 refs.

  2. KINETICS OF SLURRY PHASE FISCHER-TROPSCH SYNTHESIS

    SciTech Connect

    Dragomir B. Bukur; Gilbert F. Froment; Tomasz Olewski

    2006-09-29

    This report covers the fourth year of a research project conducted under the University Coal Research Program. The overall objective of this project is to develop a comprehensive kinetic model for slurry-phase Fischer-Tropsch synthesis (FTS) employing iron-based catalysts. This model will be validated with experimental data obtained in a stirred-tank slurry reactor (STSR) over a wide range of process conditions. The model will be able to predict molar flow rates and concentrations of all reactants and major product species (water, carbon dioxide, linear 1- and 2-olefins, and linear paraffins) as a function of reaction conditions in the STSR. During the fourth year of the project, an analysis of experimental data collected during the second year of this project was performed. Kinetic parameters were estimated utilizing product distributions from 27 mass balances. During the reporting period two kinetic models were employed: a comprehensive kinetic model of Dr. Li and co-workers (Yang et al., 2003) and a hydrocarbon selectivity model of Van der Laan and Beenackers (1998, 1999) The kinetic model of Yang et al. (2003) has 24 parameters (20 parameters for hydrocarbon formation, and 4 parameters for the water-gas-shift (WGS) reaction). Kinetic parameters for the WGS reaction and FTS synthesis were estimated first separately, and then simultaneously. The estimation of these kinetic parameters employed the Levenberg-Marquardt (LM) method and the trust-region reflective Newton large-scale (LS) method. A genetic algorithm (GA) was incorporated into estimation of parameters for FTS reaction to provide initial estimates of model parameters. All reaction rate constants and activation energies were found to be positive, but at the 95% confidence level the intervals were large. Agreement between predicted and experimental reaction rates has been fair to good. Light hydrocarbons are predicted fairly accurately, whereas the model underpredicts values of higher molecular weight

  3. Temperature distribution study in a cooled radial inflow turbine rotor

    NASA Technical Reports Server (NTRS)

    Hamed, A.; Baskharone, E.; Tabakoff, W.

    1976-01-01

    A numerical study to determine the temperature distribution in the rotor of a radial inflow turbine is presented. The study is based on the use of the finite element method in the three dimensional heat conduction problem. Different cooling techniques with various coolant to primary mass flow ratios are investigated. The resulting temperature distribution in the rotor are presented for comparison.

  4. Chemical Hydride Slurry for Hydrogen Production and Storage

    SciTech Connect

    McClaine, Andrew W

    2008-09-30

    The purpose of this project was to investigate and evaluate the attractiveness of using a magnesium chemical hydride slurry as a hydrogen storage, delivery, and production medium for automobiles. To fully evaluate the potential for magnesium hydride slurry to act as a carrier of hydrogen, potential slurry compositions, potential hydrogen release techniques, and the processes (and their costs) that will be used to recycle the byproducts back to a high hydrogen content slurry were evaluated. A 75% MgH2 slurry was demonstrated, which was just short of the 76% goal. This slurry is pumpable and storable for months at a time at room temperature and pressure conditions and it has the consistency of paint. Two techniques were demonstrated for reacting the slurry with water to release hydrogen. The first technique was a continuous mixing process that was tested for several hours at a time and demonstrated operation without external heat addition. Further work will be required to reduce this design to a reliable, robust system. The second technique was a semi-continuous process. It was demonstrated on a 2 kWh scale. This system operated continuously and reliably for hours at a time, including starts and stops. This process could be readily reduced to practice for commercial applications. The processes and costs associated with recycling the byproducts of the water/slurry reaction were also evaluated. This included recovering and recycling the oils of the slurry, reforming the magnesium hydroxide and magnesium oxide byproduct to magnesium metal, hydriding the magnesium metal with hydrogen to form magnesium hydride, and preparing the slurry. We found that the SOM process, under development by Boston University, offers the lowest cost alternative for producing and recycling the slurry. Using the H2A framework, a total cost of production, delivery, and distribution of $4.50/kg of hydrogen delivered or $4.50/gge was determined. Experiments performed at Boston

  5. Physical Characterization of Solid-Liquid Slurries at High Weight Fractions Using Optical and Ultrasonic Methods, Final Report

    SciTech Connect

    Burgess, Lloyd W.

    2009-09-17

    Remediation of highly radioactive waste is a major technical and programmatic challenge for the DOE. Rapid, on-line physical characterization of highly concentrated slurries is required for the safe and efficient remediation of 90 million gallons of high level radioactive waste (HLW), sodium bearing waste, and mixed waste. The research presented here, describes a collaborative effort between Pacific Northwest National Laboratory (PNNL) and the University of Washington to directly address the need for rapid on-line characterization of the physical properties of HLW slurries during all phases of the remediation process, from in-tank characterization of sediments to monitoring of the concentration, particle size, and degree of agglomeration and gelation of slurries during transport. Near-surface characterization of the slurry flow in the particle size range from nanometer to micrometer is examined using optical low coherence reflectometry. Volumetric characterization at depths in the slurry flow, up to several centimeters in the particle size range from the micrometer to millimeter, is realized by utilizing ultrasonic backscatter and diffuses fields. One of the strengths, the teaming up of significant talents in both experimental and theoretical optics (University of Washington) and in ultrasonics [Pacific Northwest National Laboratory (PNNL)] provides a synergistic approach to integrate these complimentary techniques. One of the benefits of this combined approach is the physical characterization of HLW over a concentration and particle size range that is broader than can be achieved with today’s technology. This will avoid a costly increase in waste stream volume due to excess dilution, and will lessen chance of plugging pipes that could shut down expensive processing lines.

  6. Microwave/Sonic Apparatus Measures Flow and Density in Pipe

    NASA Technical Reports Server (NTRS)

    Arndt, G. D.; Ngo, Phong; Carl, J. R.; Byerly, Kent A.

    2004-01-01

    An apparatus for measuring the rate of flow and the mass density of a liquid or slurry includes a special section of pipe instrumented with microwave and sonic sensors, and a computer that processes digitized readings taken by the sensors. The apparatus was conceived specifically for monitoring a flow of oil-well-drilling mud, but the basic principles of its design and operation are also applicable to monitoring flows of other liquids and slurries.

  7. Gas turbine engine with radial diffuser and shortened mid section

    SciTech Connect

    Charron, Richard C.; Montgomery, Matthew D.

    2015-09-08

    An industrial gas turbine engine (10), including: a can annular combustion assembly (80), having a plurality of discrete flow ducts configured to receive combustion gas from respective combustors (82) and deliver the combustion gas along a straight flow path at a speed and orientation appropriate for delivery directly onto the first row (56) of turbine blades (62); and a compressor diffuser (32) having a redirecting surface (130, 140) configured to receive an axial flow of compressed air and redirect the axial flow of compressed air radially outward.

  8. Hydrodynamic models for slurry bubble column reactors. Seventh technical progress report, January--March 1996

    SciTech Connect

    Gidaspow, D.

    1996-04-01

    The objective of this investigation is to convert our ``learning gas solid-liquid`` fluidization model into a predictive design model. The IIT hydrodynamic model computes the phase velocities and the volume fractions of gas, liquid and particulate phase. Model verification involves a comparison of these computed velocities and volume fractions to experimental values. A hydrodynamic model for multiphase flows, based on the principles of mass, momentum and energy conservation for each phase, was developed and applied to model gas-liquid, gas-liquid-solid fluidization and gas-solid-solid separation. To simulate the industrial slurry bubble column reactors, a computer program based on the hydrodynamic model was written with modules for chemical reactions (e.g. the synthesis of methanol), phase changes and heat exchangers. In the simulations of gas-liquid two phases flow system, the gas hold-ups, computed with a variety of operating conditions such as temperature, pressure, gas and liquid velocities, agree well with the measurements obtained at Air Products` pilot plant. The hydrodynamic model has more flexible features than the previous empirical correlations in predicting the gas hold-up of gas-liquid two-phase flow systems. In the simulations of gas-liquid-solid bubble column reactors with and without slurry circulation, the code computes volume fractions, temperatures and velocity distributions for the gas, the liquid and the solid phases, as well as concentration distributions for the species (CO, H{sub 2}, CH{sub 3}0H, ... ), after startup from a certain initial state. A kinetic theory approach is used to compute a solid viscosity due to particle collisions. Solid motion and gas-liquid-solid mixing are observed on a color PCSHOW movie made from computed time series data. The steady state and time average catalyst concentration profiles, the slurry height and the rates of methanol production agree well with the measurements obtained at an Air Products` pilot plant.

  9. Erosion in radial inflow turbines. Volume 2: Balance of centrifugal and radial drag forces on erosive particles

    NASA Technical Reports Server (NTRS)

    Clevenger, W. B., Jr.; Tabakoff, W.

    1974-01-01

    The particle motion in two-dimensional free and forced inward flowing vortices is considered. A particle in such a flow field experiences a balance between the aerodynamic drag forces that tend to drive erosive particles toward the axis, and centrifugal forces that prevent these particles from traveling toward the axis. Results predict that certain sizes of particles will achieve a stable orbit about the turbine axis in the inward flowing free vortex. In this condition, the radial drag force is equal to the centrifugal force. The sizes of particles that will achieve a stable orbit is shown to be related to the gas flow velocity diagram at a particular radius. A second analysis yields a description of particle sizes that will experience a centrifugal force that is greater than the radial component of the aerodynamic drag force for a more general type of particle motion.

  10. Effect of rotor meridional velocity ratio on response to inlet radial and circumferential distortion

    NASA Technical Reports Server (NTRS)

    Sanger, N. L.

    1979-01-01

    Three single transonic fan stages, each having a different meridional velocity ratio across its rotor, were tested with two magnitudes of tip radial distortion and with a 90 deg circumferential distortion imposed on the inlet flow. The rotor with the lowest meridional velocity ratio (less than 0.9 at the tip) demonstrated the least degradation of performance due to these distortions. Loss and deviation angle data (as needed for performance prediction with radial distortion) calculated along actual streamlines for radially distorted flow and correlated against diffusion factor, showed consistent agreement with data calculated along design streamlines for undistorted flow.

  11. Effects of radial motion on interchange injections at Saturn

    NASA Astrophysics Data System (ADS)

    Paranicas, C.; Thomsen, M. F.; Achilleos, N.; Andriopoulou, M.; Badman, S. V.; Hospodarsky, G.; Jackman, C. M.; Jia, X.; Kennelly, T.; Khurana, K.; Kollmann, P.; Krupp, N.; Louarn, P.; Roussos, E.; Sergis, N.

    2016-01-01

    Charged particle injections are regularly observed in Saturn's inner magnetosphere by Cassini. They are attributed to an ongoing process of flux-tube interchange driven by the strong centrifugal force associated with Saturn's rapid rotation. Numerical simulations suggest that these interchange injections can be associated with inward flow channels, in which plasma confined to a narrow range of longitudes moves radially toward the planet, gaining energy, while ambient plasma in the adjacent regions moves more slowly outward. Most previous analyses of these events have neglected this radial motion and inferred properties of the events under the assumption that they appear instantaneously at the spacecraft's L-shell and thereafter drift azimuthally. This paper describes features of injections that can be related to their radial motion prior to observation. We use a combination of phase space density profiles and an updated version of a test-particle model to quantify properties of the injection. We are able to infer the longitudinal width of the injection, the radial travel time from its point of origin, and the starting L shell of the injection. We can also predict which energies can remain inside the channel during the radial transport. To highlight the effects of radial propagation at a finite speed, we focus on those interchange injections without extensive features of azimuthal dispersion. Injections that have traveled radially for one or more hours prior to observation would have been initiated at a different local time than that of the observation. Finally, we describe an injection where particles have drifted azimuthally into a flow channel prior to observation by Cassini.

  12. Ice slurry based thermal storage in multifunctional buildings

    NASA Astrophysics Data System (ADS)

    Wang, M. J.; Kusumoto, N.

    Ice slurry based thermal storage plays an important role in reshaping patterns of electricity use for space cooling and heating. It offers inherent advantages in energy efficiency, operating savings, load follow-up and flexible installation over conventional thermal storage technologies. This paper provides discussions on the generation mechanism and performance of ice slurry, as well as the operation principle of the ice slurry based thermal storage system. Details of the system design, control strategy and operation performance are given through a case study on a recent installation in Herbis Osaka, the largest simple building complex in Japan. An evaluation of different installations with ice slurry thermal storage reveals that it is a rewarding technology that provides significant operating savings for the building air-conditioning and improves energy utilization efficiency in modern society.

  13. New-Generation Sealing Slurries For Borehole Injection Purposes

    NASA Astrophysics Data System (ADS)

    Stryczek, Stanisław; Gonet, Andrzej; Wiśniowski, Rafał; Złotkowski, Albert

    2015-12-01

    The development of techniques and technologies thanks to which parameters of the ground medium can be modified makes specialists look for new recipes of geopolymers - binders for the reinforcing and sealing of unstable and permeable grounds. The sealing slurries are expected to meet a number of strict requirements, therefore it is important to find new admixtures and additives which could modify the fresh and hardened slurry. Special attention has been recently paid to the fluid ash - a by-product of the combustion of hard coals. However, the use of this additive is associated with the application of appropriate superplastifier. Laboratory analyses of rheological parameters of fresh sealing slurries and the ways of improving their liquidity by a properly selected third-generation superplastifier are presented in the paper. The slurries were based on Portland cement CEM I, milled granulated large-furnace slag and fly ash from fluidized-bed combustion of hard coal.

  14. Dilute acid pretreatment of lignocellulose for whole slurry ethanol fermentation.

    PubMed

    Jung, Young Hoon; Kim, In Jung; Kim, Hyun Kyung; Kim, Kyoung Heon

    2013-03-01

    Dilute sulfuric acid pretreatment of oil palm empty fruit bunches (EFB) followed by the whole slurry fermentation of the pretreated EFB slurry was investigated. The optimized pretreatment conditions were at 1% (w/v) sulfuric acid with 3 min ramping to 190 °C in a microwave digester. Pretreated and washed EFB exhibited enzymatic digestibility of 88.5% of theoretical glucose yield after 48 h of hydrolysis. When the whole slurry of pretreated and neutralized EFB was used in simultaneous saccharification and fermentation (SSF) using cellulase and Saccharomyces cerevisiae, sulfuric acid-pretreated EFB resulted in 52.5% of theoretical ethanol yield based on total glucan in the untreated initial EFB after 72 h of SSF. When pretreated EFB slurry was treated with activated carbon before subjecting to SSF, the SSF furnished 87.5% ethanol yield based on the initial glucan content in untreated EFB (after 48 h of SSF). PMID:23395763

  15. Slurry line eminent domain urged over rail lands

    SciTech Connect

    Bagge, C.E.

    1980-06-09

    According to C.E. Bagge of the National Coal Association (NCA), Congress should pass a bill that would grant coal slurry pipelines the right-of-eminent-domain across land held by railroads. An NCA study determined that 85% of the coal shipped by U.S. railroads in 1977 could not have been shipped in any other way, and the NCA feels that the coal market would be improved if the railroads' transport dominance were reduced by the presence of slurry lines. NCA and Senator D. Bumpers would prefer that the bill under consideration be broadened to give slurry lines eminent domain over private lands, but this expansion of powers is considered politically infeasible. According to Senator W. Ford, the proposed bill would be applied primarily in eastern states, rather than in western states, as is generally thought, since eastern railroads usually own their track beds but western railroads are built on federal easements which slurry lines can cross.

  16. Radial Ion Transport in a Limited Axisymmetric Ecr Plasma.

    NASA Astrophysics Data System (ADS)

    Gibson, Gerald Warren, Jr.

    1995-01-01

    An experimental study of the radial transport of ions in the presence of a limiter for an axisymmetric plasma sustained by the resonant absorption of 2.45 GHz whistler waves is presented. In steady state, approximately 30% of the particles ionized in the core plasma flow radially into the scrape-off layer. The magnitude of radial ion flux is observed to be bounded from below by the radial electron transport rate and from above by the classical collisional ion transport rate of the cold edge ions. The system proves to be susceptible to a Kelvin-Helmholtz instability. The transport experiments were performed at a set input power of 300 W and over the neutral pressure range of 1-3 mTorr in Argon gas. The bulk ions possess a typical temperature of 1eV and do not obey a diffusion equation in the core plasma. Strong radial electric fields are observed and appear to provide the principal means by which radial ion diffusion is controlled. The presence of strongly sheared electric fields in this system excites a hydrodynamic instability of the Kelvin-Helmholtz type. The most frequently observed mode is driven by a region of depressed potential at the plasma edge. A theory for instability in the presence of a localized inverted Gaussian radial potential is presented and compared with experimental measurements. The convection of edge plasma into the core under influence of this mode leads to an increased edge temperature and, hence, enhanced axial losses from the scrape-off layer, thereby modifying the radial profile of the scrape-off layer. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.).

  17. Transport of Tank 241-SY-101 Waste Slurry: Effects of Dilution and Temperature on Critical Pipeline Velocity

    SciTech Connect

    KP Recknagle; Y Onishi

    1999-06-15

    This report presents the methods and results of calculations performed to predict the critical velocity and pressure drop required for the two-inch pipeline transfer of solid/liquid waste slurry from underground waste storage Tank 241-SY-101 to Tank 241-SY- 102 at the Hanford Site. The effects of temperature and dilution on the critical velocity were included in the analysis. These analyses show that Tank 241-SY-101 slurry should be diluted with water prior to delivery to Tank 241-SY-102. A dilution ratio of 1:1 is desirable and would allow the waste to be delivered at a critical velocity of 1.5 ft/sec. The system will be operated at a flow velocity of 6 ft/sec or greater therefore, this velocity will be sufficient to maintain a stable slurry delivery through the pipeline. The effect of temperature on the critical velocity is not a limiting factor when the slurry is diluted 1:1 with water. Pressure drop at the critical velocity would be approximately two feet for a 125-ft pipeline (or 250-ft equivalent straight pipeline). At 6 ft/sec, the pressure drop would be 20 feet over a 250-ft equivalent straight pipeline.

  18. Dewatering fine coal slurries by gel extraction. Final report

    SciTech Connect

    Gehrke, S.H.; Lyu, Lii-Hurng

    1990-12-31

    A new technology called gel extraction has been evaluated to determine its economic viability in dewatering the fine and ultrafine coal slurries generated upon separation of sulfur and ash from clean coal during the physical coal cleaning process. Water must be removed from such slurries prior to transportation and combustion but the dewatering costs are substantial, especially for the fine particles below 28 mesh (0.6 mm). Gel extraction is a potential breakthrough in slurry dewatering technology. The goal of this project was to acquire the qualitative and quantitative data needed to estimate the potential of gel extraction for dewatering coal slurries. The specific objectives were to determine the maximum extents of dewatering (minimum surface moisture in the coal product), the clarity of the water removed (minimum solids content), the speed of the dewatering cycles, the service lifetime of the gels, and the factors which influence all of these. With the results obtained, an economic analysis of Ohio coal cleaning plant dewatering technologies was carried out. The polymer gel at the heart of this project, poly (N-isopropylacrylamide) (PNIPA), can swell several times its shrunken weight at 32{degrees}C by absorbing water at 25{degrees}C. In gel extraction, a shrunken NIPA gel is contacted with a slurry at ambient temperature or cooler; the gel swells by absorbing water from the slurry. The gel is then removed from the dewatered slurry and warmed above its critical temperature of 33{degrees}C, which returns it to the shrunken state by releasing the absorbed water. The facts that the gel is reusable and the process is simple and driven by low-grade energy (warm temperatures), and not inherently limited by particle size, made the process an attractive possible alternative to centrifugation, screening, filtration, etc. for slurry dewatering.

  19. Elaboration of metal matrix composites from thixotropic alloy slurries using a new magnetohydrodynamic caster

    NASA Astrophysics Data System (ADS)

    Vivès, Charles

    1993-06-01

    The working principle and the peculiarities of a new electromagnetic rheocaster, which is based on the use of rotating permanent magnets and which allows the production of intense three-dimensional (3-D) multiphase flows in solidifying semisolid alloy slurries and metal matrix composites, are described. This process can be applied to the direct continuous casting of billets, tubes, and slabs and is characterized by very low electric power consumption. Local measurement techniques are applied to the study of the evolution of non-Newtonian magnetohydrodynamic multiphase flow phenomena with the rotational speed of the inductor, the solid fraction of the aluminum alloy matrix, and the size and volume percent of SiC particles. An order of magnitude analysis of the various forces acting on the suspended crystals and SiC particles is given. The Theological behavior of electromagnetically rheocast ferrous metals, simulated by a lead-tin alloy, is also investigated. Satisfactory results concerning the microstructure of solidified aluminum slurries and aluminum matrix composites (homogeneity, crystal shape, grain size, fraction of primary solid, and distribution of SiC particles) were obtained. A discussion is presented relating the metallurgical findings to the heat and three-phase flow measurements.

  20. Parachute drag and radial force

    SciTech Connect

    Purvis, J.W.

    1986-01-01

    This paper presents a combination of old and new wind tunnel data in a format which illustrates the effects of inflated diameter, geometric porosity, reefing line length, suspension line length, number of gores, and number of ribbons on parachute drag. A new definition of radial force coefficient is presented, as well as a universal drag curve for flat circular and conical parachutes.