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Sample records for free-surface lithium flow

  1. Incompressible Flows Free Surfaces

    1992-02-01

    NASA-VOF3D is a three-dimensional, transient, free surface, incompressible fluid dynamics program. It is specifically designed to calculate confined flows in a low gravity environment in which surface physics must be accurately treated. It allows multiple free surfaces with surface tension and wall adhesion and includes a partial cell treatment that allows curved boundaries and internal obstacles. Variable mesh spacing is permitted in all three coordinate directions. Boundary conditions available are rigid free-slip wall, rigid no-slipmore » wall, continuative, periodic, and specified pressure outflow boundary.« less

  2. Retention/Diffusivity Studies in Free-Surface Flowing Liquid Lithium

    SciTech Connect

    R.A. Stubbers; G.H. Miley; M. Nieto; W. Olczak; D.N. Ruzic; A. Hassanein

    2004-12-14

    FLIRE was designed to measure the hydrogen and helium retention and diffusivity in a flowing stream of liquid lithium, and it has accomplished these goals. Retention coefficients for helium in the flowing liquid stream were 0.1-2% for flow speeds of 44 cm/s and implantation energies between 500 and 2000 eV. The energy dependence of retention is linear for the energy range considered, as expected, and the dependence of retention on flow velocity fits the expected square-root of flow speed dependence. Estimates of the helium diffusion coefficient in the flowing lithium stream were {approx} 4 x 10{sup -7} cm{sup 2}/s, and are independent of implantation energy. This value is much lower than expected, which could be due to several factors, such as mixing, bubble formation or surface film formation. In the case of hydrogen, long term retention and release mechanisms are of greatest importance, since this relates to tritium inventory in flowing lithium PFCs for fusion applications. The amount of hydride formation was measured for flowing lithium exposed to neutral deuterium gas. Thermal desorption spectroscopy (TDS) measurements indicate that the hydride concentration was between 0.1 and 0.2% over a wide range of pressures (6.5 x 10{sup -5} to 1 Torr). This result implies that the deuterium absorption rate is limited by the surface dissociation rate, since deuterium (hydrogen/tritium) is absorbed in its atomic form, not its molecular form.

  3. Free-surface and coating flows

    NASA Astrophysics Data System (ADS)

    Ashmore, Jacqueline

    In thus thesis we present results on four problems which fall into the class of free-surface flows. Two of the problems relate to coating flows, in which a thin film of fluid is deposited on a moving substrate. The third problem concerns the motion of a sphere down an inclined plane that is coated with a thin film of viscous fluid. Finally, we study the Rayleigh capillary instability of a cylindrical fluid thread surrounded by a second viscous fluid in a rotating frame. One useful tool for analysis of coating flows is the method of matched asymptotics, which enables us to obtain a solution to the nonlinear third-order differential equation that describes the free-surface shape in two of the problems we study. The first coating flow problem we consider is the interface shape of fluid inside a horizontal cylinder rotating about its axis with a small fraction of its volume filled with viscous Newtonian fluid. By accounting for surface tension effects we find a new axially uniform steady solution valid at low rotation rates. Predictions for the scalings based on matched asymptotic methods are confirmed numerically. Secondly, theoretical predictions of the film thickness that coats a substrate when it is withdrawn from a bath of viscoelastic fluid are presented, for a number of substrate geometries. In the third problem studied, we use lubrication analysis to characterize the steady translational velocity and rotation rate of a sphere that moves down an inclined plane, which is coated with a thin film of fluid, under the action of gravity. In this case, an understanding of the fluid flow must be used to determine the forces that act on the sphere, which set the translational speed and rotation rate of the sphere. Finally, we study the effect of the Coriolis force on the Rayleigh capillary instability of a cylindrical column of viscous liquid surrounded by a second viscous liquid in a rotating frame. Our study comprises numerical results of a temporal linear stability

  4. Application of the PTT model to axisymmetric free surface flows

    NASA Astrophysics Data System (ADS)

    Merejolli, R.; Paulo, G. S.; Tomé, M. F.

    2013-10-01

    This work is concerned with numerical simulation of axisymmetric viscoelastic free surface flows using the Phan-Thien-Tanner (PTT) constitutive equation. A finite difference technique for solving the governing equations for unsteady incompressible flows written in Cylindrical coordinates on a staggered grid is described. The fluid is modelled by a Marker-and-Cell type method and an accurate representation of the fluid surface is employed. The full free surface stress conditions are applied. The numerical method is verified by comparing numerical predictions of fully developed flow in a pipe with the corresponding analytic solutions. To demonstrate that the numerical method can simulate axisymmetric free surface flows governed by the PTT model, numerical results of the flow evolution of a drop impacting on a rigid dry plate are presented. In these simulations, the rheological effects of the parameters ɛ and ξ are investigated.

  5. Energy-decomposition analysis for viscous free-surface flows.

    PubMed

    Colagrossi, Andrea; Bouscasse, Benjamin; Marrone, Salvatore

    2015-11-01

    This work is dedicated to the energy decomposition analysis of a viscous free-surface flow. In the presence of a free surface, the viscous dissipation for a Newtonian liquid can be decomposed into two terms: an enstrophy component and a free-surface deformation component. The latter requires the evaluation of volume and surface integrals in the meshless framework. The analysis is based on the weakly compressible smoothed particle hydrodynamics formalism. The behavior of the energy terms is studied in standing wave problems by changing the viscosity and the wave amplitude. Finally, an analysis of a complex shallow water breaking wave case is provided. It is shown that in presence of intense breaking phenomena the two energy components are always comparable, whereas generally the free surface component is dominant on the viscous dissipation of gravity waves. PMID:26651775

  6. Energy-decomposition analysis for viscous free-surface flows

    NASA Astrophysics Data System (ADS)

    Colagrossi, Andrea; Bouscasse, Benjamin; Marrone, Salvatore

    2015-11-01

    This work is dedicated to the energy decomposition analysis of a viscous free-surface flow. In the presence of a free surface, the viscous dissipation for a Newtonian liquid can be decomposed into two terms: an enstrophy component and a free-surface deformation component. The latter requires the evaluation of volume and surface integrals in the meshless framework. The analysis is based on the weakly compressible smoothed particle hydrodynamics formalism. The behavior of the energy terms is studied in standing wave problems by changing the viscosity and the wave amplitude. Finally, an analysis of a complex shallow water breaking wave case is provided. It is shown that in presence of intense breaking phenomena the two energy components are always comparable, whereas generally the free surface component is dominant on the viscous dissipation of gravity waves.

  7. Computation of turbulent free-surface flows around modern ships

    NASA Astrophysics Data System (ADS)

    Li, Tingqiu

    2003-10-01

    This paper presents the calculated results for three classes of typical modern ships in modelling of ship-generated waves. Simulations of turbulent free-surface flows around ships are performed in a numerical water tank, based on the FINFLO-RANS SHIP solver developed at Helsinki University of Technology. The Reynolds-averaged Navier-Stokes (RANS) equations with the artificial compressibility and the non-linear free-surface boundary conditions are discretized by means of a cell-centred finite-volume scheme. The convergence performance is improved with the multigrid method. A free surface is tracked using a moving mesh technology, in which the non-linear free-surface boundary conditions are given on the actual location of the free surface. Test cases recommended are a container ship, a US Navy combatant and a tanker. The calculated results are compared with the experimental data available in the literature in terms of the wave profiles, wave pattern, and turbulent flow fields for two turbulence models, Chien's low Reynolds number k-model and Baldwin-Lomax's model. Furthermore, the convergence performance, the grid refinement study and the effect of turbulence models on the waves have been investigated. Additionally, comparison of two types of the dynamic free-surface boundary conditions is made.

  8. Local mesh refinement for incompressible fluid flow with free surfaces

    SciTech Connect

    Terasaka, H.; Kajiwara, H.; Ogura, K.

    1995-09-01

    A new local mesh refinement (LMR) technique has been developed and applied to incompressible fluid flows with free surface boundaries. The LMR method embeds patches of fine grid in arbitrary regions of interest. Hence, more accurate solutions can be obtained with a lower number of computational cells. This method is very suitable for the simulation of free surface movements because free surface flow problems generally require a finer computational grid to obtain adequate results. By using this technique, one can place finer grids only near the surfaces, and therefore greatly reduce the total number of cells and computational costs. This paper introduces LMR3D, a three-dimensional incompressible flow analysis code. Numerical examples calculated with the code demonstrate well the advantages of the LMR method.

  9. Numerical study of free surface flow around large obstacles

    NASA Astrophysics Data System (ADS)

    Zhang, Yanming

    In this thesis a numerical model was developed to study three-dimensional turbulent flows around large obstacles in an open channel. With this numerical model, a series of numerical tests was carried out, and the properties of turbulent flows around a single obstacle or a cluster of obstacles were investigated. The origin of this study was to study the flow properties around fish habitat structures. Actually, the numerical model can be applied to the study of general turbulent flows under free surfaces. In the numerical model the three-dimensional Reynolds-averaged Navier-Stokes equations in conjunction with k-epsilon turbulence model were solved in a free surface fitted coordinate system. First, different forms of governing equations for turbulent flow were investigated, and a concise form of fully transformed governing equations in a general curvilinear coordinate system was derived. In the numerical solution the FAVOR (Fractional Area/Volume Obstacle Representation) technique was extended into the free surface fitted coordinate system. With this feature the problem of complex turbulent flow with a free surface and general shaped obstacles could be solved efficiently. To locate the free surface, a method based on integrating the momentum equation in the vertical direction was developed. After study and tests of several popular difference schemes, a QUICK scheme with UMIST limiter was adopted in this numerical model. Several test cases were presented to demonstrate the present numerical model. The first test case was to simulate a submerged hydraulic jump. The calculated velocity, free surface profile and turbulence properties of the flow showed a close match with the experimental data. The second test was a submerged hydraulic jump with a baffle sill. The comparison between numerical and experimental data indicated that the current numerical model could catch the general flow structures of the submerged hydraulic jumps. The last two test cases were flows around a

  10. Free surface and flow problem for a viscous liquid

    SciTech Connect

    Zaytsev, M. L. Akkerman, V. B.

    2011-10-15

    An exact closed system of equations is proposed for describing the shape of the free surface of a viscous steady-state liquid in the 2D case in terms of the surface itself. A method that lowers the dimensionality in the Navier-Stokes equation is demonstrated, and its application in problems of steady-state flow past solids is considered.

  11. Wetting and free surface flow modeling for potting and encapsulation.

    SciTech Connect

    Brooks, Carlton, F.; Brooks, Michael J. (Los Alamos National Laboratory, Los Alamos, NM); Graham, Alan Lyman; Noble, David F. ); Notz, Patrick K.; Hopkins, Matthew Morgan; Castaneda, Jaime N.; Mahoney, Leo James; Baer, Thomas A.; Berchtold, Kathryn (Los Alamos National Laboratory, Los Alamos, NM); Adolf, Douglas Brian; Wilkes, Edward Dean; Rao, Rekha Ranjana; Givler, Richard C.; Sun, Amy Cha-Tien; Cote, Raymond O.; Mondy, Lisa Ann; Grillet, Anne Mary; Kraynik, Andrew Michael

    2007-06-01

    As part of an effort to reduce costs and improve quality control in encapsulation and potting processes the Technology Initiative Project ''Defect Free Manufacturing and Assembly'' has completed a computational modeling study of flows representative of those seen in these processes. Flow solutions are obtained using a coupled, finite-element-based, numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. In addition, two commercially available codes, ProCAST and MOLDFLOW, are also used on geometries representing encapsulation processes at the Kansas City Plant. Visual observations of the flow in several geometries are recorded in the laboratory and compared to the models. Wetting properties for the materials in these experiments are measured using a unique flowthrough goniometer.

  12. Energy flow and energy dissipation in a free surface.

    NASA Astrophysics Data System (ADS)

    Goldburg, Walter; Cressman, John

    2005-11-01

    Turbulent flows on a free surface are strongly compressible [1] and do not conserve energy in the absence of viscosity as bulk fluids do. Despite violation of assumptions essential to Kolmogorov's theory of 1941 (K41) [2, 3], surface flows show strong agreement with Kolmogorov scaling, though intermittency is larger there. Steady state turbulence is generated in a tank of water, and the spatially averaged energy flux is measured from the four-fifth's law at each instant of time. Likewise, the energy dissipation rate as measured from velocity gradients is also a random variable in this experiment. The energy flux - dissipation rate cross-correlation is measured to be correlated in incompressible bulk flows, but strongly anti-correlated on the surface. We argue that the reason for this discrepancy between surface and bulk flows is due to compressible effects present on the surface. [1] J. R. Cressman, J. Davoudi, W. I. Goldburg, and J. Schumacher, New Journal of Physics, 6, 53, 2004. [2] U. Frisch. Turbulence: The legacy of A. N. Kolmogorov, Cambridge University Press, Cambridge, 1995. [3] A. N. Kolmogorov, Doklady Akad. Nauk SSSR, 32, 16, 1941.

  13. Rotating polygon instability of a swirling free surface flow.

    PubMed

    Tophøj, L; Mougel, J; Bohr, T; Fabre, D

    2013-05-10

    We explain the rotating polygon instability on a swirling fluid surface [G. H. Vatistas, J. Fluid Mech. 217, 241 (1990) and Jansson et al., Phys. Rev. Lett. 96, 174502 (2006)] in terms of resonant interactions between gravity waves on the outer part of the surface and centrifugal waves on the inner part. Our model is based on potential flow theory, linearized around a potential vortex flow with a free surface for which we show that unstable resonant states appear. Limiting our attention to the lowest order mode of each type of wave and their interaction, we obtain an analytically soluble model, which, together with estimates of the circulation based on angular momentum balance, reproduces the main features of the experimental phase diagram. The generality of our arguments implies that the instability should not be limited to flows with a rotating bottom (implying singular behavior near the corners), and indeed we show that we can obtain the polygons transiently by violently stirring liquid nitrogen in a hot container.

  14. Computation of rapidly varied unsteady, free-surface flow

    USGS Publications Warehouse

    Basco, D.R.

    1987-01-01

    Many unsteady flows in hydraulics occur with relatively large gradients in free surface profiles. The assumption of hydrostatic pressure distribution with depth is no longer valid. These are rapidly-varied unsteady flows (RVF) of classical hydraulics and also encompass short wave propagation of coastal hydraulics. The purpose of this report is to present an introductory review of the Boussinnesq-type differential equations that describe these flows and to discuss methods for their numerical integration. On variable slopes and for large scale (finite-amplitude) disturbances, three independent derivational methods all gave differences in the motion equation for higher order terms. The importance of these higher-order terms for riverine applications must be determined by numerical experiments. Care must be taken in selection of the appropriate finite-difference scheme to minimize truncation error effects and the possibility of diverging (double mode) numerical solutions. It is recommended that practical hydraulics cases be established and tested numerically to demonstrate the order of differences in solution with those obtained from the long wave equations of St. Venant. (USGS)

  15. Measurement of the interaction between the flow and the free surface of a liquid

    SciTech Connect

    Okamoto, Koji; Schmidl, W.D.; Philip, O.G.

    1995-09-01

    The interaction between the flow and free surface was evaluated measuring the velocity distribution and surface movement simultaneously. The test section was a rectangular tank having a free surface. A rectangular nozzle was set near the free surface, causing the wavy free surface condition. The flow under the free surface was visualized by a laser light sheet and small tracer particles. With image processing techniques, the movement of the free surface and the movement of the particles were simultaneously measured from the recorded images, resulting in the velocity distributions and surface locations. Then, the interactions between the flow and free surface were evaluated using the form of turbulent energy and surface-related turbulent values. By increasing the turbulent energy near the free surface, the fluctuations of the free surface height and the inclination of the free surface were increased. The higher fluctuation of horizontal velocity was related to the higher surface position and negative inclination. The image processing technique is found to be very useful to evaluate the interaction between free surface and flow.

  16. Method of driving liquid flow at or near the free surface using magnetic microparticles

    DOEpatents

    Snezhko, Oleksiy; Aronson, Igor; Kwok, Wai-Kwong; Belkin, Maxim V.

    2011-10-11

    The present invention provides a method of driving liquid flow at or near a free surface using self-assembled structures composed of magnetic particles subjected to an external AC magnetic field. A plurality of magnetic particles are supported at or near a free surface of liquid by surface tension or buoyancy force. An AC magnetic field traverses the free surface and dipole-dipole interaction between particles produces in self-assembled snake structures which oscillate at the frequency of the traverse AC magnetic field. The snake structures independently move across the free surface and may merge with other snake structures or break up and coalesce into additional snake structures experiencing independent movement across the liquid surface. During this process, the snake structures produce asymmetric flow vortices across substantially the entirety of the free surface, effectuating liquid flow across the free surface.

  17. Selected flows with free surfaces: Streams and drops

    NASA Astrophysics Data System (ADS)

    Kowalewski, Tomasz A.

    1995-03-01

    The basic purpose of the research described in this article was to develop a non contact method for diagnosing the physical parameters of the free surface of a liquid using drop oscillation analysis. In particular, the purpose is to measure the temperature of an evaporating surface. The realization of this goal has led to the development of new experimental techniques which make it possible to record fast processes using video and digital imaging equipment. Experimental studies of the process of the formation of drops as a result of the controlled breakup of a stream revealed the existence of an additional phase in the process based on the formation of microstreams and microsatellites with micrometer-like dimensions. A comparison of measurement results with Eggers' asymptotic model (23) confirmed the model's basic assumption of the local nature of the final phase in the disintegration of the stream, which at the same time points to the existence of a number of discrepancies which provide evidence of the limitations of this approximation. The next part of the article presents the results of observations of the instability of streams of liquid caused by its evaporation. In an attempt to analyze the mechanisms which initiate the turbulence of the evaporating surface, the author focused on surface tension gradients as an essential factor in the destabilization of small-diameter streams. The author also described the occurrence of a number of new phenomena in the destabilization of a stream, including the separation of surface fragments, their stabilization by the flow of vapor, and a quasistable change in the trajectory of the stream. The author also developed an experimental method which makes it possible to detect and produce a precise description of the deformation of drops. Measurements of the oscillations of small drops in the air led to the development of a complete non-linear model of the oscillations of a viscous drop and made it possible to verify simplified

  18. Flow of a Non-Newtonian Liquid with a Free Surface

    NASA Astrophysics Data System (ADS)

    Borzenko, E. I.; Shrager, G. R.

    2016-07-01

    A fountain flow of a non-Newtonian liquid filling a vertical plane channel was investigated. The problem of this flow was solved by the finite-difference method on the basis of a system of complete equations of motion with natural boundary conditions on the free surface of the liquid. The stability of calculations was provided by regularization of the rheological Ostwald-de Waele law. It is shown that the indicated flow is divided into a zone of two-dimensional flow in the neighborhood of the free surface and a zone of one-dimensional flow at a distance from this surface. A parametric investigation of the dependence of the kinetic characteristics of the fountain flow and the behavior of its free surface on the determining criteria of this flow and its rheological parameters has been performed.

  19. Penalty-finite element analysis of time-dependent two-dimensional free surface film flows

    NASA Astrophysics Data System (ADS)

    Kheshgi, H. S.; Scriven, L. E.

    The Navier-Stokes system with shear-free balanced normal stress and with kinematic boundary conditions at the free surface, which governs the flow of incompressible Newtonian liquid films, is presently solved by the penalty/Galerkin/FEM technique, employing both a tesselation that deforms with the free surface and an implicit time domain method. Results are given for the case of transient flow out of a coating slot, and a more brief presentation of results is made for the cases of the capillary leveling of a disturbed film, the damping of standing waves, and evolving disturbances in a film flowing down an inclined plane.

  20. Nonlinear dynamics and breakup of free-surface flows

    SciTech Connect

    Eggers, J.

    1997-07-01

    Surface-tension-driven flows and, in particular, their tendency to decay spontaneously into drops have long fascinated naturalists, the earliest systematic experiments dating back to the beginning of the 19th century. Linear stability theory governs the onset of breakup and was developed by Rayleigh, Plateau, and Maxwell. However, only recently has attention turned to the nonlinear behavior in the vicinity of the singular point where a drop separates. The increased attention is due to a number of recent and increasingly refined experiments, as well as to a host of technological applications, ranging from printing to mixing and fiber spinning. The description of drop separation becomes possible because jet motion turns out to be effectively governed by one-dimensional equations, which still contain most of the richness of the original dynamics. In addition, an attraction for physicists lies in the fact that the separation singularity is governed by universal scaling laws, which constitute an asymptotic solution of the Navier-Stokes equation before and after breakup. The Navier-Stokes equation is thus continued uniquely through the singularity. At high viscosities, a series of noise-driven instabilities has been observed, which are a nested superposition of singularities of the same universal form. At low viscosities, there is rich scaling behavior in addition to aesthetically pleasing breakup patterns driven by capillary waves. The author reviews the theoretical development of this field alongside recent experimental work, and outlines unsolved problems. {copyright} {ital 1997} {ital The American Physical Society}

  1. Effect of free surface on near-wake flow of elliptic cylinders with different aspect ratios

    NASA Astrophysics Data System (ADS)

    Lee, Sang Joon; Daichin, -

    2003-04-01

    The flow fields behind elliptic cylinders with different aspect ratios adjacent to a free surface were investigated experimentally in a circulating water channel. The elliptic cylinders tested in this study have same cross section area. For each elliptic cylinder, the experiments were carried out under different conditions by varying the submergence depth of the cylinder beneath the free surface. The flow fields were measured using a single-frame double-exposure PIV system. For each experimental condition, 350 instantaneous velocity fields were captured and ensemble-averaged to obtain the mean flow field information and spatial distribution of turbulent statistics. The near-wakes can be basically classified into three typical patterns, which are formation of Coanda effect, generation of substantial jet-like flow, and attachment of jet flow to the free surface. The general flow structures behind the elliptic cylinder are similar to previous results for a circular submerged near to a free surface. However, the wake width and the angle of downward deflection of the shear layer developed from the lower surface of the elliptic cylinder are smaller than those for the circular cylinder. These trends are enhance with increasing of the cylinder aspect ratios.

  2. Mode formation of free surface rotating flow between concentric vertical cylinders

    NASA Astrophysics Data System (ADS)

    Watanabe, T.; Toya, Y.; Nakamura, I.

    2008-11-01

    Mode exchanges of flows between concentric and rotating cylinders with vertical axes have been studied by numerical and experimental approaches. The lengths of the cylinders are finite, and the inner cylinder rotates and the outer cylinder is stationary. The bottom end wall of the annulus is a fixed solid wall and the top is a free surface between a working liquid and the air, and the wall condition is axially asymmetric. This gives one of the modifications of Taylor-Couette system. In this system, the normal mode flow has an inward flow on the lower end wall and an outward flow near the free surface. In experiment, visualized flows are observed from the top and the side of the cylinders, and the position of the free surface is measured. Numerical methods are based on the unsteady axisymmetric equations, and the gravitational acceleration and the surface tension are considered to formulate the dynamics of the free surface. The experimental result and numerical result show the primary mode, the secondary normal mode and the anomalous mode, which are similar to the modes found in the symmetric system. The regions where the primary modes and the normal secondary modes appear are determined in the space spanned by the Reynolds number and the aspect ratio.

  3. A Robust volume conservative divergence-free ISPH framework for free-surface flow problems

    NASA Astrophysics Data System (ADS)

    Pahar, Gourabananda; Dhar, Anirban

    2016-10-01

    This study presents a Volume Conservative approach for resolving volume conservation issue in divergence-free incompressible Smoothed Particle Hydrodynamics (ISPH). Irregular free surface deformation may introduce error in volume computation, which has a cascading effect over time. Proposed correction decreases this numerical compressibility to a minimal value. The correction is obtained directly by solving Navier-Stokes momentum equation. Consequently, the framework does not require any parametric study for mixed source/sink term or iterative solution of pressure Poisson equations. The correction is implemented on four different types of flow: (a) pressurized flow in a closed box, (b) dambreak flow, (c) flow through porous block, (d) lock-exchange flow of immiscible fluids (both free-surface and pressurized flow). All four scenarios are shown to have minimal error compared to pure divergence-free ISPH.

  4. Two-dimensional free surface flow in branch channels by a finite-volume TVD scheme

    NASA Astrophysics Data System (ADS)

    Wang, Jiasong; He, Yousheng; Ni, Hangen

    Free surface flow, in particular caused by dam-breaks in branch channels or other arbitrary geometrical rivers is an attention getting subject to the engineering practice, however the studies are few to be reported. In this paper a finite-volume total variation diminishing (TVD) scheme is presented for modeling unsteady free surface flows caused by dam-breaks in branch channels. In order to extend the finite-difference TVD scheme to finite-volume form, a mesh topology is defined relating a node and an element. The solver is implemented for the 2D shallow water equations on arbitrary quadrilateral meshes, and based upon a second-order hybrid TVD scheme with an optimum-selected limiter in the space discretization and a two-step Runge-Kutta approach in the time discretization. Verification for two typical dam-break problems is carried out by comparing the present results with others and very good agreement is obtained. The present algorithm is then used to predict the characteristics of free surface flows due to dam breaking in branch channels, for example, in a symmetrical trifurcated channel and a natural bifurcated channel, on coarse meshes and fine meshes, respectively. The characteristics of complex unsteady free surface flows in these examples are clearly shown.

  5. Mechanism and flow measurement of AC electrowetting propulsion on free surface

    NASA Astrophysics Data System (ADS)

    Yuan, Junqi; Cho, Sung Kwon

    2015-03-01

    A free surface in contact with a floating object can be vertically oscillated by applying an alternating current electrowetting-on-dielectric (AC EWOD). The oscillation of the free surface generates a propelling force on the centimeter-sized floating object. This paper describes a propulsion mechanism in free-surface oscillation along with its experimental results. Flow visualizations, wave patterns measured by the free-surface synthetic schlieren method, and PIV measurements show that the oscillation generates a capillary Stokes drift on the water surface and two counter-rotating spiral underwater vortices, leading to an ejecting flow (streaming flow) normal to the wall of the boat. The momentum of the ejecting flow produces a reaction force on the wall and ultimately propels the floating boat. The propulsion speed of the boat highly depends on the amplitude, frequency, and shape of the AC EWOD signal. Curve fittings based on the Stokes drift well match the experimental measurements of propulsion speed. The width of the EWOD electrode also has significant effects on the boat speed.

  6. Phase-detection measurements in free-surface turbulent shear flows

    NASA Astrophysics Data System (ADS)

    Chanson, Hubert

    2016-04-01

    High-velocity self-aerated flows are described as ‘white waters’ because of the entrained air bubbles. The air entrainment induces a drastic change in the multiphase flow structure of the water column and this leads to significant bubble-turbulence interactions, turbulence modulation and associated mixing processes impacting on the bulk flow properties. In these high-velocity free-surface turbulent flows, the phase-detection needle probe is a most reliable instrumentation. The signal processing of a phase-detection probe is re-visited herein. It is shown that the processing may be performed on the raw probe signal as well as the thresholded data. The latter yields the time-averaged void fraction, the bubble count rate, the particle chord time distributions and the particle clustering properties within the particulate flow regions. The raw probe signal analysis gives further the auto-correlation time scale and the power spectrum density function. Finally dimensional considerations are developed with a focus on the physical modelling of free-surface flows in hydraulic structures. It is argued that the notion of scale effects must be defined in terms of some specific set of air-water flow properties within well-defined testing conditions, while a number of free-surface flow characteristics are more prone to scale effects than others, even in large-size physical facilities.

  7. An extended validation of the last generation of particle finite element method for free surface flows

    NASA Astrophysics Data System (ADS)

    Gimenez, Juan M.; González, Leo M.

    2015-03-01

    In this paper, a new generation of the particle method known as Particle Finite Element Method (PFEM), which combines convective particle movement and a fixed mesh resolution, is applied to free surface flows. This interesting variant, previously described in the literature as PFEM-2, is able to use larger time steps when compared to other similar numerical tools which implies shorter computational times while maintaining the accuracy of the computation. PFEM-2 has already been extended to free surface problems, being the main topic of this paper a deep validation of this methodology for a wider range of flows. To accomplish this task, different improved versions of discontinuous and continuous enriched basis functions for the pressure field have been developed to capture the free surface dynamics without artificial diffusion or undesired numerical effects when different density ratios are involved. A collection of problems has been carefully selected such that a wide variety of Froude numbers, density ratios and dominant dissipative cases are reported with the intention of presenting a general methodology, not restricted to a particular range of parameters, and capable of using large time-steps. The results of the different free-surface problems solved, which include: Rayleigh-Taylor instability, sloshing problems, viscous standing waves and the dam break problem, are compared to well validated numerical alternatives or experimental measurements obtaining accurate approximations for such complex flows.

  8. Evolution of karst conduit networks in transition from pressurized flow to free-surface flow

    NASA Astrophysics Data System (ADS)

    Perne, M.; Covington, M.; Gabrovšek, F.

    2014-11-01

    Most of the existing models of speleogenesis are limited to situations where flow in all conduits is pressurized. The feedback between the distribution of hydraulic head and growth of new solution conduits determines the geometry of the resulting conduit network. We present a novel modeling approach that allows a transition from pressurized (pipe) flow to a free-surface (open-channel) flow in evolving discrete conduit networks. It calculates flow, solute transport and dissolution enlargement within each time step and steps through time until a stable flow pattern is established. The flow in each time step is calculated by calling the US Environmental Protection Agency Storm Water Management Model (US Environmental Protection Agency, 2014), which efficiently solves the 1-D Saint-Venant equations in a network of conduits. Two basic scenarios are modeled, a low-dip scenario and a high-dip scenario. In the low-dip scenario a slightly inclined plane is populated with a rectangular grid of solution conduits. The recharge is distributed to randomly selected junctions. The results for the pressurized flow regime resemble those of the existing models. When the network becomes vadose, a stable flow pathway develops along a system of conduits that occupy the lowest positions at their inlet junctions. This depends on the initial diameter and inlet position of a conduit, its total incision in a pressurized regime and its alignment relative to the dip of the plane, which plays important role during the vadose entrenchment. In the high-dip scenario a sub-vertical network with recharge on the top and outflow on the side is modeled. It is used to demonstrate the vertical development of karst due to drawdown of the water table, development of invasion vadose caves during vadose flow diversion and to demonstrate the potential importance of deeply penetrating conductive structures.

  9. Evolution of karst conduit networks in transition from pressurised flow to free surface flow

    NASA Astrophysics Data System (ADS)

    Perne, M.; Covington, M. D.; Gabrovšek, F.

    2014-06-01

    We present a novel modelling approach to study the evolution of conduit networks in soluble rocks. Unlike the models presented so far, the model allows a transition from pressurised (pipe) flow to a free surface (open channel) flow in evolving discrete conduit networks. It calculates flow, solute transport and dissolutional enlargement within each time step and steps through time until a stable flow pattern establishes. The flow in each time step is calculated by calling the EPA Storm Water Management Model (EPA SWMM), which efficiently solves the 1-D Saint Venant equations in a network of conduits. We present several cases with low dip and sub-vertical networks to demonstrate mechanisms of flow pathway selection. In low dip models the inputs were randomly distributed to several junctions. The evolution of pathways progresses upstream: initially pathways linking outlets to the closest inputs evolve fastest because the gradient along these pathways is largest. When a pathway efficiently drains the available recharge, the head drop along the pathway attracts flow from the neighbouring upstream junctions and new connecting pathways evolve. The mechanism progresses from the output boundary inwards until all inputs are connected to the stable flow system. In the pressurised phase, each junction is drained by at least one conduit, but only one conduit remains active in the vadose phase. The selection depends on the initial geometry of a junction, initial distribution of diameters, the evolution in a pressurised regime, and on the dip of the conduits, which plays an important role in vadose entrenchment. In high dip networks, the vadose zone propagates downwards and inwards from the rim of the massif. When a network with randomly distributed initial diameters is supplied with concentrated recharge from the adjacent area, the sink point regresses up upstream along junctions connected to the prominent pathways. Large conductive structures provide deep penetration of high

  10. On the Nature of Boundary Conditions for Flows with Moving Free Surfaces

    NASA Astrophysics Data System (ADS)

    Renardy, Michael; Renardy, Yuriko

    1991-04-01

    We consider small perturbations of plane parallel flow between a wall and a moving free surface. The problem is posed on a rectangle with inflow and outflow boundaries. The usual boundary conditions are posed at the wall and the free surface, and the fluid satisfies the Navier-Stokes equations. We examine the nature of boundary conditions which can be imposed at the inflow and outflow boundaries in order to yield a well-posed problem. This question turns out to be more delicate than is generally appreciated. Depending on the precise situation and on the regularity required of the solution, boundary conditions at just one or both endpoints of the free surface need to be imposed. For example, we show that if the velocities at te inflow and outflow boundaries are prescribed, then the position of the free surface at the inflow boundary can be prescribed, but not at the outflow if an H1-solution is desired. Numerical simulations with the FIDAP package are used to illustrate our analytical results.

  11. Coupling of Smoothed Particle Hydrodynamics with Finite Volume method for free-surface flows

    NASA Astrophysics Data System (ADS)

    Marrone, S.; Di Mascio, A.; Le Touzé, D.

    2016-04-01

    A new algorithm for the solution of free surface flows with large front deformation and fragmentation is presented. The algorithm is obtained by coupling a classical Finite Volume (FV) approach, that discretizes the Navier-Stokes equations on a block structured Eulerian grid, with an approach based on the Smoothed Particle Hydrodynamics (SPH) method, implemented in a Lagrangian framework. The coupling procedure is formulated in such a way that each solver is applied in the region where its intrinsic characteristics can be exploited in the most efficient and accurate way: the FV solver is used to resolve the bulk flow and the wall regions, whereas the SPH solver is implemented in the free surface region to capture details of the front evolution. The reported results clearly prove that the combined use of the two solvers is convenient from the point of view of both accuracy and computing time.

  12. Parallel Simulation of Three-Dimensional Free Surface Fluid Flow Problems

    SciTech Connect

    BAER,THOMAS A.; SACKINGER,PHILIP A.; SUBIA,SAMUEL R.

    1999-10-14

    Simulation of viscous three-dimensional fluid flow typically involves a large number of unknowns. When free surfaces are included, the number of unknowns increases dramatically. Consequently, this class of problem is an obvious application of parallel high performance computing. We describe parallel computation of viscous, incompressible, free surface, Newtonian fluid flow problems that include dynamic contact fines. The Galerkin finite element method was used to discretize the fully-coupled governing conservation equations and a ''pseudo-solid'' mesh mapping approach was used to determine the shape of the free surface. In this approach, the finite element mesh is allowed to deform to satisfy quasi-static solid mechanics equations subject to geometric or kinematic constraints on the boundaries. As a result, nodal displacements must be included in the set of unknowns. Other issues discussed are the proper constraints appearing along the dynamic contact line in three dimensions. Issues affecting efficient parallel simulations include problem decomposition to equally distribute computational work among a SPMD computer and determination of robust, scalable preconditioners for the distributed matrix systems that must be solved. Solution continuation strategies important for serial simulations have an enhanced relevance in a parallel coquting environment due to the difficulty of solving large scale systems. Parallel computations will be demonstrated on an example taken from the coating flow industry: flow in the vicinity of a slot coater edge. This is a three dimensional free surface problem possessing a contact line that advances at the web speed in one region but transitions to static behavior in another region. As such, a significant fraction of the computational time is devoted to processing boundary data. Discussion focuses on parallel speed ups for fixed problem size, a class of problems of immediate practical importance.

  13. An improved parallel SPH approach to solve 3D transient generalized Newtonian free surface flows

    NASA Astrophysics Data System (ADS)

    Ren, Jinlian; Jiang, Tao; Lu, Weigang; Li, Gang

    2016-08-01

    In this paper, a corrected parallel smoothed particle hydrodynamics (C-SPH) method is proposed to simulate the 3D generalized Newtonian free surface flows with low Reynolds number, especially the 3D viscous jets buckling problems are investigated. The proposed C-SPH method is achieved by coupling an improved SPH method based on the incompressible condition with the traditional SPH (TSPH), that is, the improved SPH with diffusive term and first-order Kernel gradient correction scheme is used in the interior of the fluid domain, and the TSPH is used near the free surface. Thus the C-SPH method possesses the advantages of two methods. Meanwhile, an effective and convenient boundary treatment is presented to deal with 3D multiple-boundary problem, and the MPI parallelization technique with a dynamic cells neighbor particle searching method is considered to improve the computational efficiency. The validity and the merits of the C-SPH are first verified by solving several benchmarks and compared with other results. Then the viscous jet folding/coiling based on the Cross model is simulated by the C-SPH method and compared with other experimental or numerical results. Specially, the influences of macroscopic parameters on the flow are discussed. All the numerical results agree well with available data, and show that the C-SPH method has higher accuracy and better stability for solving 3D moving free surface flows over other particle methods.

  14. Extension of physical component BFC method for the analysis of free-surface flows coupled with moving boundaries

    NASA Astrophysics Data System (ADS)

    Lu, D.; Takizawa, A.; Kondo, S.

    A newly developed ``physical component boundary fitted coordinate (PCBFC) method'' is extended for the analysis of free-surface flows coupled with moving boundaries. Extra techniques are employed to deal with the coupling movement of the free surface and moving boundaries. After the validation of the extension by several benchmark problems, the method is successfully applied for the first time to the simulation of overflow-induced vibration of the weir coupled with sloshing of the free-surface liquid.

  15. Simulation of gravity driven free-surface flow in fractured geological media

    SciTech Connect

    Kordilla, Jannes; Geyer, Tobias; Tartakovsky, Alexandre M.

    2011-08-25

    Abstract—Simulation of unsaturated free-surface flow in fractured geological media represents a challenge due to the highly heterogeneous flow field induced by extensive faults, joints and fissures. Free-surface flow in unsaturated media leads to highly intermittent flow regimes and flow velocities well above those assumed for the bulk volume. However, common modeling approaches relying on volume-averaged effective equations fail to capture this flow feature. In this work we present micro-scale flow simulations using a three-dimensional multiphase SPH code. Pairwise fluid-fluid and solid-fluid interaction forces are used to simulate a wide range of wetting conditions encountered on rock surfaces. It is shown that static contact angles for sessiles droplets are independent of the model discretization, i.e. the total amount of particles. Thus, computation times can be reduced without sacrificing qualitative or quantitative information. Furthermore we show that our model is in accordance with general scaling laws for droplet flow.

  16. Three-dimensional low Reynolds number flows with a free surface

    NASA Technical Reports Server (NTRS)

    Degani, D.; Gutfinger, C.

    1977-01-01

    The two-dimensional leveling problem (Degani, Gutfinger, 1976) is extended to three dimensions in the case where the flow Re number is very low and attention is paid to the free surface boundary condition with surface tension effects included. The no-slip boundary condition on the wall is observed. The numerical solution falls back on the Marker and Cell (MAC) method (Harlow and Welch, 1965) with the computation region divided into a finite number of stationary rectangular cells (or boxes in the 3-D case) and fluid flow traverses the cells (or boxes).

  17. Note: Proton irradiation at kilowatt-power and neutron production from a free-surface liquid-lithium target

    NASA Astrophysics Data System (ADS)

    Halfon, S.; Arenshtam, A.; Kijel, D.; Paul, M.; Weissman, L.; Aviv, O.; Berkovits, D.; Dudovitch, O.; Eisen, Y.; Eliyahu, I.; Feinberg, G.; Haquin, G.; Hazenshprung, N.; Kreisel, A.; Mardor, I.; Shimel, G.; Shor, A.; Silverman, I.; Tessler, M.; Yungrais, Z.

    2014-05-01

    The free-surface Liquid-Lithium Target, recently developed at Soreq Applied Research Accelerator Facility (SARAF), was successfully used with a 1.9 MeV, 1.2 mA (2.3 kW) continuous-wave proton beam. Neutrons (˜2 × 1010 n/s having a peak energy of ˜27 keV) from the 7Li(p,n)7Be reaction were detected with a fission-chamber detector and by gold activation targets positioned in the forward direction. The setup is being used for nuclear astrophysics experiments to study neutron-induced reactions at stellar energies and to demonstrate the feasibility of accelerator-based boron neutron capture therapy.

  18. Note: Proton irradiation at kilowatt-power and neutron production from a free-surface liquid-lithium target.

    PubMed

    Halfon, S; Arenshtam, A; Kijel, D; Paul, M; Weissman, L; Aviv, O; Berkovits, D; Dudovitch, O; Eisen, Y; Eliyahu, I; Feinberg, G; Haquin, G; Hazenshprung, N; Kreisel, A; Mardor, I; Shimel, G; Shor, A; Silverman, I; Tessler, M; Yungrais, Z

    2014-05-01

    The free-surface Liquid-Lithium Target, recently developed at Soreq Applied Research Accelerator Facility (SARAF), was successfully used with a 1.9 MeV, 1.2 mA (2.3 kW) continuous-wave proton beam. Neutrons (~2 × 10(10) n/s having a peak energy of ~27 keV) from the (7)Li(p,n)(7)Be reaction were detected with a fission-chamber detector and by gold activation targets positioned in the forward direction. The setup is being used for nuclear astrophysics experiments to study neutron-induced reactions at stellar energies and to demonstrate the feasibility of accelerator-based boron neutron capture therapy.

  19. Nanometer-scale free surface flow of molten polyethylene from a heated atomic force microscope tip

    NASA Astrophysics Data System (ADS)

    Ewoldt, Randy; Felts, Jonathan; Somnath, Suhas; King, William

    2012-11-01

    We experimentally investigate nanometer-scale free surface flow of molten polyethylene from a heated atomic force microscope (AFM) cantilever, a nanofabrication process known as thermal dip-pen nanolithography (tDPN). Fluid is deposited from the AFM tip onto non-porous substrates whether the tip is moving or fixed. We find that polymer flow depends on surface capillary forces and not on shear between tip and substrate. The polymer mass flow rate is sensitive to the temperature-dependent polymer viscosity. Additionally, the flow rate increases when a temperature gradient exists between the tip and substrate. We hypothesize that the polymer flow is governed by thermal Marangoni forces and non-equilibrium wetting dynamics caused by a solidification front within the feature.

  20. Motion of a cylinder adjacent to a free-surface: flow patterns and loading

    NASA Astrophysics Data System (ADS)

    Zhu, Q.; Lin, J.-C.; Unal, M. F.; Rockwell, D.

    The flow structure and loading due to combined translatory and sinusoidal motion of a cylinder adjacent to a free-surface are characterized using a cinema technique of high-image-density particle image velocimetry and simultaneous force measurements. The instantaneous patterns of vorticity and streamline topology are interpreted as a function of degree of submergence beneath the free-surface. The relative magnitudes of the peak vorticity and the circulation of vortices formed from the upper and lower surfaces of the cylinder, as well as vortex formation from the free-surface, are remarkably affected by the nominal submergence. The corresponding streamline topology, interpreted in terms of foci, saddle points, and multiple separation and reattachment points also exhibit substantial changes with submergence. All of these features affect the instantaneous loading of the cylinder. Calculation of instantaneous moments of vorticity and the incremental changes in these moments during the cylinder motion allow identification of those vortices that contribute most substantially to the instantaneous lift and drag. Furthermore, the calculated moments are in general accord with the time integrals of the measured lift and drag acting on the cylinder for sufficiently large submergence.

  1. Comparison of Flow Characteristics of Different Sphere Geometries Under the Free Surface Effect

    NASA Astrophysics Data System (ADS)

    Ozgoren, M.; Dogan, S.; Okbaz, A.; Aksoy, M. H.; Sahin, B.; Akıllı, H.

    2013-04-01

    Comparison of the experimental results of turbulent flow structures between a smooth sphere and a sphere with a vent hole, roughened, and o-ring is presented in the presence of a free-surface. Dye visualization and particle image velocimetry (PIV) techniques were performed to examine effects of passive control methods on the sphere wake for Reynolds number Re = 5000 based on the sphere diameter with a 42.5mm in an open water channel. Instantaneous and time-averaged flow patterns in the wake region of the sphere were examined from point of flow physics for the different sphere locations in the range of 0≤h/D≤2.0 where h was the space between the top point of the sphere and the free surface. The ratio of ventilation hole to sphere diameter was 0.15, o-ring was located at 55° with a 2 mm from front stagnation point of the sphere and roughened surface was formed by means of totally 410 circular holes with a 3 mm diameter and around 2 mm depth in an equilateral triangle arrangement. The flow characteristics of instantaneous velocity vectors, vorticity contours, time-averaged streamline patterns, Reynolds stress correlations and streamwise and cross-stream velocity fluctuations for both the smooth and passively controlled sphere were interpreted.

  2. Upscale energy transfer and flow topology in free-surface turbulence.

    PubMed

    Lovecchio, Salvatore; Zonta, Francesco; Soldati, Alfredo

    2015-03-01

    Free-surface turbulence, albeit constrained onto a two-dimensional space, exhibits features that barely resemble predictions of simplified two-dimensional modeling. We demonstrate that, in a three-dimensional open channel flow, surface turbulence is characterized by upscale energy transfer, which controls the long-term evolution of the larger scales. We are able to associate downscale and upscale energy transfer at the surface with the two-dimensional divergence of velocity. We finally demonstrate that surface compressibility confirms the strongly three-dimensional nature of surface turbulence.

  3. An improved weakly compressible SPH method for simulating free surface flows of viscous and viscoelastic fluids

    NASA Astrophysics Data System (ADS)

    Xu, Xiaoyang; Deng, Xiao-Long

    2016-04-01

    In this paper, an improved weakly compressible smoothed particle hydrodynamics (SPH) method is proposed to simulate transient free surface flows of viscous and viscoelastic fluids. The improved SPH algorithm includes the implementation of (i) the mixed symmetric correction of kernel gradient to improve the accuracy and stability of traditional SPH method and (ii) the Rusanov flux in the continuity equation for improving the computation of pressure distributions in the dynamics of liquids. To assess the effectiveness of the improved SPH algorithm, a number of numerical examples including the stretching of an initially circular water drop, dam breaking flow against a vertical wall, the impact of viscous and viscoelastic fluid drop with a rigid wall, and the extrudate swell of viscoelastic fluid have been presented and compared with available numerical and experimental data in literature. The convergent behavior of the improved SPH algorithm has also been studied by using different number of particles. All numerical results demonstrate that the improved SPH algorithm proposed here is capable of modeling free surface flows of viscous and viscoelastic fluids accurately and stably, and even more important, also computing an accurate and little oscillatory pressure field.

  4. Efficient Computation of N-S Equation with Free Surface Flow Around an ACV on ShirazUCFD Grid

    NASA Astrophysics Data System (ADS)

    Sheikhalishahi, Seyyed Mehdi; Alizadehrad, Davood; Dastghaibyfard, Gholamhossein; Alishahi, Mohammad Mehdi; Nikseresht, Amir Hossein

    This paper presents the application of a parallel high accuracy simulation code for Incompressible Navier-Stokes solution with free surface flow around an ACV (Air Cushion Vehicle) on ShirazUCFD Grid environment. The parallel finite volume code is developed for incompressible Navier-Stokes solver on general curvilinear coordinates system for modeling free surface flows. A single set of dimensionless equations is derived to handle both liquid and air phases in viscous incompressible free surface flow in general curvilinear coordinates. The volume of fluid (VOF) method with lagrangian propagation in computational domain for modeling the free surface flow is implemented. The parallelization approach uses a domain decomposition method for the subdivision of the numerical grid, the SPMD program model and MPICH-G2 as the message passing environment is used to obtain a portable application.

  5. Time-dependent liquid metal flows with free convection and free surfaces

    SciTech Connect

    McClelland, M.A.

    1990-11-01

    A finite element analysis is given for time-dependent liquid metal flows with free convection and free surfaces. Consideration is given to a two-dimensional shallow trough with vertical walls maintained at different temperatures. The spatial formulation incorporates mixed Lagrangian approximations to the velocity, pressure, temperature, and interface position. The time integration method is performed using the Trapezoid Rule with step-size control. The Galerkin method is employed to reduce the problem to a set of nonlinear algebraic equations which are solved with the Newton-Raphson method. Calculations are performed for conditions relevant to the electron beam vaporization of refractory metals. The Prandtl number is 0.015, and Grashof numbers are in the transition region between laminar and turbulent flow. The results reveal the effects of flow intensity, surface-tension gradients, and mesh and time-step refinement.

  6. Application of the Analogy Between Water Flow with a Free Surface and Two-Dimensional Compressible Gas Flow

    NASA Technical Reports Server (NTRS)

    Orlin, W James; Lindner, Norman J; Butterly, Jack G

    1947-01-01

    The theory of the hydraulic analogy -- that is, the analogy between water flow with a free surface and two-dimensional compressible gas flow -- and the limitations and conditions of the analogy are discussed. A test was run using the hydraulic analogy as applied to the flow about circular cylinders of various diameters at subsonic velocities extending into the supercritical range. The apparatus and techniques used in this application are described and criticized. Reasonably satisfactory agreement of pressure distributions and flow fields existed between water and air flow about corresponding bodies. This agreement indicated the possibility of extending experimental compressibility research by new methods.

  7. Incompressible SPH Model for Simulating Violent Free-Surface Fluid Flows

    NASA Astrophysics Data System (ADS)

    Staroszczyk, Ryszard

    2014-06-01

    In this paper the problem of transient gravitational wave propagation in a viscous incompressible fluid is considered, with a focus on flows with fast-moving free surfaces. The governing equations of the problem are solved by the smoothed particle hydrodynamics method (SPH). In order to impose the incompressibility constraint on the fluid motion, the so-called projection method is applied in which the discrete SPH equations are integrated in time by using a fractional-step technique. Numerical performance of the proposed model has been assessed by comparing its results with experimental data and with results obtained by a standard (weakly compressible) version of the SPH approach. For this purpose, a plane dam-break flow problem is simulated, in order to investigate the formation and propagation of a wave generated by a sudden collapse of a water column initially contained in a rectangular tank, as well as the impact of such a wave on a rigid vertical wall. The results of simulations show the evolution of the free surface of water, the variation of velocity and pressure fields in the fluid, and the time history of pressures exerted by an impacting wave on a wall.

  8. Application of the Analogy Between Water Flow with a Free Surface and Two-dimensional Compressible Gas Flow

    NASA Technical Reports Server (NTRS)

    Orlin, W James; Lindner, Norman J; Bitterly, Jack G

    1947-01-01

    The theory of hydraulic analogy, that is, the analogy between water flow with a free surface and two-dimensional compressible gas flow and the limitations and conditions of the analogy are discussed. A test run was made using the hydraulic analogy as applied to the flow about circular cylinders at various diameters at subsonic velocities extending to the super critical range. The apparatus and techniques used in this application are described and criticized. Reasonably satisfactory agreement of pressure distributions and flow fields existed between water and airflow about corresponding bodies. This agreement indicated the possibility of extending experimental compressibility research by new methods.

  9. Investigation of ALEGRA shock hydrocode algorithms using an exact free surface jet flow solution.

    SciTech Connect

    Hanks, Bradley Wright.; Robinson, Allen C

    2014-01-01

    Computational testing of the arbitrary Lagrangian-Eulerian shock physics code, ALEGRA, is presented using an exact solution that is very similar to a shaped charge jet flow. The solution is a steady, isentropic, subsonic free surface flow with significant compression and release and is provided as a steady state initial condition. There should be no shocks and no entropy production throughout the problem. The purpose of this test problem is to present a detailed and challenging computation in order to provide evidence for algorithmic strengths and weaknesses in ALEGRA which should be examined further. The results of this work are intended to be used to guide future algorithmic improvements in the spirit of test-driven development processes.

  10. Strongly coupled partitioned approach for fluid structure interaction in free surface flows

    NASA Astrophysics Data System (ADS)

    Facci, Andrea Luigi; Ubertini, Stefano

    2016-06-01

    In this paper we describe and validate a methodology for the numerical simulation of the fluid structure interaction in free surface flows. Specifically, this study concentrates on the vertical impact of a rigid body on the water surface, (i.e. on the hull slamming problem). The fluid flow is modeled through the volume of fluid methodology, and the structure dynamics is described by the Newton's second law. An iterative algorithm guarantees the tight coupling between the fluid and solid solvers, allowing the simulations of lightweight (i.e. buoyant) structures. The methodology is validated comparing numerical results to experimental data on the free fall of different rigid wedges. The correspondence between numerical results and independent experimental findings from literature evidences the reliability and the accuracy of the proposed approach.

  11. Theory for source-responsive and free-surface film modeling of unsaturated flow

    USGS Publications Warehouse

    Nimmo, J.R.

    2010-01-01

    A new model explicitly incorporates the possibility of rapid response, across significant distance, to substantial water input. It is useful for unsaturated flow processes that are not inherently diffusive, or that do not progress through a series of equilibrium states. The term source-responsive is used to mean that flow responds sensitively to changing conditions at the source of water input (e.g., rainfall, irrigation, or ponded infiltration). The domain of preferential flow can be conceptualized as laminar flow in free-surface films along the walls of pores. These films may be considered to have uniform thickness, as suggested by field evidence that preferential flow moves at an approximately uniform rate when generated by a continuous and ample water supply. An effective facial area per unit volume quantitatively characterizes the medium with respect to source-responsive flow. A flow-intensity factor dependent on conditions within the medium represents the amount of source-responsive flow at a given time and position. Laminar flow theory provides relations for the velocity and thickness of flowing source-responsive films. Combination with the Darcy-Buckingham law and the continuity equation leads to expressions for both fluxes and dynamic water contents. Where preferential flow is sometimes or always significant, the interactive combination of source-responsive and diffuse flow has the potential to improve prediction of unsaturated-zone fluxes in response to hydraulic inputs and the evolving distribution of soil moisture. Examples for which this approach is efficient and physically plausible include (i) rainstorm-generated rapid fluctuations of a deep water table and (ii) space- and time-dependent soil water content response to infiltration in a macroporous soil. ?? Soil Science Society of America.

  12. Surface Ripples Generated in a Couette Flow with a Free Surface

    NASA Astrophysics Data System (ADS)

    Masnadi, N.; Washuta, N.; Duncan, J. H.

    2014-11-01

    Free surface ripples created by subsurface turbulence in the gap between a vertical surface-piercing moving wall and a parallel fixed wall are studied experimentally. The moving wall is created with the aide of a meter-wide stainless steel belt that travels horizontally in a loop around two rollers with vertically oriented axes, which are separated by 7.5 meters. One of the two 7.5-m-long belt sections between the rollers is in contact with the water in a large open-surface water tank and forms the moving wall. The fixed wall is an acrylic plate located 4 cm from the belt surface. The water surface ripples are measured in a plane normal to the belt using a cinematic LIF technique. Measurements are done at a location about 100 gap widths downstream of the leading edge of the fixed plate in order to have a fully developed flow condition. It is found that the overall RMS surface fluctuations increase linearly with belt speed. The frequency-domain spectra of the surface height fluctuation and its temporal derivative are computed at locations across the gap width and are used to explore the physics of the free surface motions. The support of the Office of Naval Research is gratefully acknowledged.

  13. Measurements of gas/oil free surface deformation caused by parallel gas flow

    NASA Astrophysics Data System (ADS)

    Matsunaga, T.; Mialdun, A.; Nishino, K.; Shevtsova, V.

    2012-06-01

    Flow-induced dynamic free-surface deformations are experimentally studied in a confined liquid volume of 5cSt silicone oil (Prandtl number Pr = 68). The geometry of the problem is a liquid column concentrically surrounded by an annular gas channel. A gas stream entering the duct from the top or bottom entrains the motionless liquid. The dynamic deformation of the gas-liquid interface is caused by a steady axisymmetric shear-driven flow. The experiments are performed in normal gravity conditions and the static deformation of a liquid bridge interface is unavoidable. The magnitude and shape of the dynamic surface deformation are analyzed using optical measurements with a comprehensive treatment of the images. The deviation of the free surface shape from the corresponding equilibrium profile is determined with an uncertainty of about 0.1 μm. The order of magnitude of the interface deformation is proportional to the capillary number, which is defined as the ratio of the viscous force per unit area to the capillary pressure. The study is performed for a large range of volumes and aspect ratios as well as for different gas velocities. As a general trend, the dynamic deformation grows with the gas velocity, which plays the role of a driving force, but a linear dependence is not observed for all volume ratios, despite the small Reynolds numbers, 280 < Reg < 560. The dynamic deformation displays a strong dependence on the liquid volume ratio and the direction of the gas stream parallel to the interface. When the gas flow is directed against gravity, the largest interface deformations are observed at the smallest volumes among the analyzed ones. In contrast, when the gas stream is aligned with gravity, then the deformations decrease with a decrease in the volume ratio, at a certain value attaining zero (vanishing) and then changing sign.

  14. Circular flow formation triggered by Marangoni convection in nematic liquid crystal films with a free surface.

    PubMed

    Choi, Hyunhee; Takezoe, Hideo

    2016-01-14

    We demonstrate circular flow formation at a surface in homeotropically oriented nematic liquid crystals with a free surface using focused laser beam irradiation. Under a weak laser power, a pit together with an associated circular bulge is formed: the Marangoni effect. Here a diverging molecular flow from the pit (thermocapillary flow) also induces director tilt in the radial direction. Upon increasing the laser power, the pit becomes deeper, and eventually evolves into a circular flow associated with a deeper pit and a subsidiary circular bulge or valley structure. This phenomenon is induced by escaping from excess deformation energy due to a bend deformation of the director. Actually, we confirmed that the circular flow is never formed in the isotropic phase. The handedness of the vortex cannot be controlled by circular polarisation, but is controllable by doping with chiral molecules. This rotational motion (a nematic micro-rotor) is a unique phenomenon only exhibited by anisotropic liquids, and is expected to be applied for novel devices. PMID:26482229

  15. GENSMAC: A computational marker and cell method for free surface flows in general domains

    NASA Astrophysics Data System (ADS)

    Tome, Murilo F.; McKee, Sean

    1994-01-01

    A computer program for solving two-dimensional incompressible viscous fluid flow in general domains is described. This is based on the simplified Marker and cell technique, but it has a number of novel features. A user-supplied data file of coordinates prescribes the fluid domain which can be quite general and needs only to be connected. With a view to parallelization the momentum equations are solved explicitly, but an automatic step-changing routine optimizes the stability restriction. A conjugate gradient solver is used to invert the discrete Poisson equation. An accurate approximation to the stress conditions on the free surface is adopted. The code is written in structured FORTRAN with features from FORTRAN 90. The efficacy of the code is illustrated by applying it to some industrial problems.

  16. Near-wake flow structure of elliptic cylinders close to a free surface: effect of cylinder aspect ratio

    NASA Astrophysics Data System (ADS)

    Daichin, K. V.; Lee, Sang Joon

    The flow fields behind elliptic cylinders adjacent to a free surface were investigated experimentally in a circulating water channel. A range of cylinder aspect ratios (AR=2, 3, 4) were considered, while the cross-sectional area of the elliptical cylinder was kept constant. The main objective of this study was to investigate the effect of cylinder aspect ratio and a free surface on the flow structure in the near-wake behind elliptic cylinders. For each elliptic cylinder, the flow structure was analyzed for various values of the submergence depth of the cylinder beneath the free surface. The flow fields were measured using a single-frame double-exposure PIV (Particle Image Velocimetry) system. For each experimental condition, 350 instantaneous velocity fields were obtained and ensemble-averaged to obtain the mean velocity field and spatial distribution of the mean vorticity statistics. The results show that near-wake can be classified into three typical flow patterns: formation of a Coanda flow, generation of substantial jet-like flow, and attachment of this jet flow to the free surface. The general flow structure observed behind the elliptic cylinders resembles the structure previously reported for a circular cylinder submerged near a free surface. However, the wake width and the angle of downward deflection of the shear layer developed from the lower surface of the elliptic cylinder differ from those observed for a circular cylinder. These trends are enhanced as cylinder aspect ratio is increased. In addition, the free surface distortion is also discussed in the paper.

  17. Performance and Near-Wake Flow field of A Marine Hydrokinetic Turbine Operating in Free surface Proximity

    NASA Astrophysics Data System (ADS)

    Banerjee, Arindam; Kolekar, Nitin

    2015-11-01

    The current experimental investigation aims at understanding the effect of free surface proximity and associated blockage on near-wake flow-field and performance of a three bladed horizontal axis marine hydrokinetic turbine. Experiments were conducted on a 0.14m radius, three bladed constant chord turbine in a 0.61m ×0.61m test section water channel. The turbine was subjected to various rotational speeds, flow speeds and depths of immersion. Experimental data was acquired through a submerged in-line thrust-torque sensor that was corrected to an unblocked dataset with a blockage correction using measured thrust data. A detailed comparison is presented between blocked and unblocked datasets to identify influence of Reynolds number and free surface proximity on blockage effects. The percent change in Cp was found to be dependent on flow velocity, rotational speed and free surface to blade tip clearance. Further, flow visualization using a stereoscopic particle image velocimetry was carried out in the near-wake region of turbine to understand the mechanism responsible for variation of Cp with rotational speed and free surface proximity. Results revealed presence of slower wake at higher rotational velocities and increased asymmetry in the wake at high free surface proximity.

  18. Free surface due to a flow driven by a rotating disk inside a vertical cylindrical tank: Axisymmetric configuration

    NASA Astrophysics Data System (ADS)

    Kahouadji, L.; Witkowski, L. Martin

    2014-07-01

    The flow driven by a rotating disk at the bottom of an open fixed cylindrical cavity is studied numerically and experimentally. The steady axisymmetric Navier-Stokes equations projected onto a curvilinear coordinate system are solved by a Newton-Raphson algorithm. The free surface shape is computed by an iterative process in order to satisfy a zero normal stress balance at the interface. In previous studies, regarding the free surface deflection, there is a significant disagreement between a first-order approximation [M. Piva and E. Meiburg, "Steady axisymmetric flow in an open cylindrical container with a partially rotating bottom wall," Phys. Fluids 17, 063603 (2005)] and a full numerical simulation [R. Bouffanais and D. Lo Jacono, "Unsteady transitional swirling flow in the presence of a moving free surface," Phys. Fluids 21, 064107 (2009)]. For a small deflection, the first-order approximation matches with our numerical simulation and for a large deflection a good agreement is found with experimental measurements.

  19. Free surface flow impact on a vertical wall: a numerical assessment

    NASA Astrophysics Data System (ADS)

    Pugliese Carratelli, Eugenio; Viccione, Giacomo; Bovolin, Vittorio

    2016-10-01

    The sudden impact of a free surface flow upon a solid wall is a common occurrence in many situations in nature and technology. The design of marine structures is probably the most obvious example, but also river and dam hydraulics as well as the necessity of understanding flood and debris flow-induced damage have led to theoretical and experimental work on the mechanism of fluid slamming loads. This is therefore a very old and rich research field, which has not yet reached full maturity, so that semi-empirical methods in design practice are still the rule in many sectors. Up-to-date CFD technology with both Eulerian and Lagrangian approaches is employed to investigate highly non-stationary fluid impact on a solid wall. The development of the pressure wave produced by the impact is examined as it propagates and interacts with the fluid boundaries, as well as the subsequent build-up of high-pressure gradients of high fluid velocities. The geometry and the velocity field of the problem considered are very simple, but the results seem to provide new insight, in particular, into the connection between phenomena with different timescales.

  20. Velocity profiles and plug zones in a free surface viscoplastic flow : experimental study and comparison to shallow flow models

    NASA Astrophysics Data System (ADS)

    Freydier, Perrine; Chambon, Guillaume; Naaim, Mohamed

    2016-04-01

    Rheological studies concerning natural muddy debris flows have shown that these materials can be modelled as non-Newtonian viscoplastic fluids. These complex flows are generally represented using models based on a depth-integrated approach (Shallow Water) that take into account closure terms depending on the shape of the velocity profile. But to date, there is poor knowledge about the shape of velocity profiles and the position of the interface between sheared and unsheared regions (plug) in these flows, especially in the vicinity of the front. In this research, the internal dynamics of a free-surface viscoplastic flow down an inclined channel is investigated and compared to the predictions of a Shallow Water model based on the lubrication approximation. Experiments are conducted in an inclined channel whose bottom is constituted by an upward-moving conveyor belt with controlled velocity, which allows generating and observing gravity-driven stationary surges in the laboratory frame. Carbopol microgel has been used as a homogeneous and transparent viscoplastic fluid. High-resolution measurements of velocity field is performed through optical velocimetry techniques both in the uniform zone and within the front zone where flow thickness is variable and where recirculation takes place. Specific analyses have been developed to determine the position of the plug within the surge. Flow height is accessible through image processing and ultrasonic sensors. Sufficiently far from the front, experimental results are shown to be in good agreement with theoretical predictions regarding the velocity profiles and the flow height evolution. In the vicinity of the front, however, analysis of measured velocity profiles shows an evolution of the plug different from that predicted by lubrication approximation. Accordingly, the free surface shape also deviates from the predictions of the classical Shallow Water model. These results highlight the necessity to take into account higher

  1. Flow, heat transfer, and free surface shape during the optical fiber drawing process

    NASA Astrophysics Data System (ADS)

    Xiao, Zhihui

    1997-12-01

    A two-dimensional finite element model is introduced for analyzing glass and gas flows, heat transfer, and fiber formation during the optical fiber drawing process. This study consists of simulations in three different areas: the upper region, the tip region, and the whole furnace region. Conjugating the glass and gas flows and heat transfer, the shapes of an optical fiber as free surfaces in the upper neck-down and the tip regions are separately obtained by solving the coupled continuity, momentum, and energy equations. In the upper region simulation, a surface-to-surface radiation model is used for the enclosure which consists of the wall and the glass surface, and the Rosseland approximation radiation model is employed to account for the radiation effect in the glass region. In the tip region simulation, only the glass fiber region is considered and a convective heat transfer model on the fiber surface is employed to account for the energy exchange between the fiber surface and the purge gas. In the fiber, radiation in the axial direction is included. The whole furnace simulation uses a calculated fiber neck-down shape and an assumed fiber tip shape as a fixed interface and computes the convective heat transfer coefficient profile in the tip region which was used in the tip region simulation. The glass viscosity is temperature-dependent and significantly affects the fiber shape. The finite element code FIDAP is used in the study. The effects of various operating conditions such as draw speed, wall temperature distribution, and gas flow rate are studied.

  2. Granular-front formation in free-surface flow of concentrated suspensions.

    PubMed

    Leonardi, Alessandro; Cabrera, Miguel; Wittel, Falk K; Kaitna, Roland; Mendoza, Miller; Wu, Wei; Herrmann, Hans J

    2015-11-01

    A granular front emerges whenever the free-surface flow of a concentrated suspension spontaneously alters its internal structure, exhibiting a higher concentration of particles close to its front. This is a common and yet unexplained phenomenon, which is usually believed to be the result of fluid convection in combination with particle size segregation. However, suspensions composed of uniformly sized particles also develop a granular front. Within a large rotating drum, a stationary recirculating avalanche is generated. The flowing material is a mixture of a viscoplastic fluid obtained from a kaolin-water dispersion with spherical ceramic particles denser than the fluid. The goal is to mimic the composition of many common granular-fluid materials, such as fresh concrete or debris flow. In these materials, granular and fluid phases have the natural tendency to separate due to particle settling. However, through the shearing caused by the rotation of the drum, a reorganization of the phases is induced, leading to the formation of a granular front. By tuning the particle concentration and the drum velocity, it is possible to control this phenomenon. The setting is reproduced in a numerical environment, where the fluid is solved by a lattice-Boltzmann method, and the particles are explicitly represented using the discrete element method. The simulations confirm the findings of the experiments, and provide insight into the internal mechanisms. Comparing the time scale of particle settling with the one of particle recirculation, a nondimensional number is defined, and is found to be effective in predicting the formation of a granular front. PMID:26651686

  3. Granular-front formation in free-surface flow of concentrated suspensions

    NASA Astrophysics Data System (ADS)

    Leonardi, Alessandro; Cabrera, Miguel; Wittel, Falk K.; Kaitna, Roland; Mendoza, Miller; Wu, Wei; Herrmann, Hans J.

    2015-11-01

    A granular front emerges whenever the free-surface flow of a concentrated suspension spontaneously alters its internal structure, exhibiting a higher concentration of particles close to its front. This is a common and yet unexplained phenomenon, which is usually believed to be the result of fluid convection in combination with particle size segregation. However, suspensions composed of uniformly sized particles also develop a granular front. Within a large rotating drum, a stationary recirculating avalanche is generated. The flowing material is a mixture of a viscoplastic fluid obtained from a kaolin-water dispersion with spherical ceramic particles denser than the fluid. The goal is to mimic the composition of many common granular-fluid materials, such as fresh concrete or debris flow. In these materials, granular and fluid phases have the natural tendency to separate due to particle settling. However, through the shearing caused by the rotation of the drum, a reorganization of the phases is induced, leading to the formation of a granular front. By tuning the particle concentration and the drum velocity, it is possible to control this phenomenon. The setting is reproduced in a numerical environment, where the fluid is solved by a lattice-Boltzmann method, and the particles are explicitly represented using the discrete element method. The simulations confirm the findings of the experiments, and provide insight into the internal mechanisms. Comparing the time scale of particle settling with the one of particle recirculation, a nondimensional number is defined, and is found to be effective in predicting the formation of a granular front.

  4. Role of algal biofilm in improving the performance of free surface, up-flow constructed wetland.

    PubMed

    Badhe, Neha; Saha, Shaswati; Biswas, Rima; Nandy, Tapas

    2014-10-01

    The role of algal biofilm in a pilot-scale, free-surface, up-flow constructed wetland (CW), was studied for its effect on chemical oxygen demand (COD), ammonia and phosphate removal during three seasons-autumn, winter and early spring. Effect of hydraulic retention time (HRT) was also investigated in presence and absence of algal biofilm. Principal Component Analysis was used to identify the independent factors governing the performance of CW. The study showed algal biofilm significantly improved nutrient removal, especially phosphate. Ammonia removal varied with HRT, biofilm and ambient temperature. Increase in biofilm thickness affected ammonia removal efficiency adversely. Algal biofilm-assisted COD removal compensated for reduced macrophyte density during winter. Two-way ANOVA test and the coefficients of dependent factors derived through multiple linear regression model confirmed role of algal biofilm in improving nutrient removal in CW. The study suggests that algal biofilm can be a green solution for bio-augmenting COD and nutrient removal in CW. PMID:25105266

  5. Nonlinear Rayleigh-Taylor instability for hydromagnetic Darcian flow: effect of free surface currents.

    PubMed

    El-Dib, Yusry O

    2003-03-15

    Capillary-gravity waves of permanent form at the interface between two unbounded magnetic fluids in porous media are investigated. The system is influenced by the horizontal direction of the magnetic field to the separation face of two semi-infinite homogeneous and incompressible fluids, so that the fields allow free-surface currents at the interface. The solutions of the linearized equations of motion under nonlinear boundary conditions lead to derivation of a nonlinear equation governing the interfacial displacement. This equation is accomplished by using the cubic nonlinearity. Taylor theory is used to expand the governing nonlinear equation in the light of the multiple scales in both space and time. The perturbation analysis leads to imposition of two levels of solvability conditions, which are used to construct the well-known nonlinear Ginzburg-Landau equation. The stability criteria are discussed theoretically and numerically and stability diagrams are obtained. Regions of stability and instability are identified for the surface current density. It is found that the stabilizing role for the magnetic field is retarded when the flow is in porous media. Moreover, the increase in the values of resistance parameters plays a dual role, in stability behavior and in the increase in surface current density.

  6. Experimental study of free-surface flow instability and bedforms in shallow flows.

    USGS Publications Warehouse

    Karcz, I.; Kersey, D.

    1980-01-01

    To test erosion and development of bed sculpture in unstable, pulsating shallow flow, 3 series of experiments were performed in a 10-m flume with flows of Reynolds Number up to 103, Froude Number up to 3.0, and slope up to 2%. In the first, the bed was rigid, in the second and third series planar beds were made from well-sorted and poorly sorted sand, respectively. Development of flow surface instability above the rigid bed showed the following stages: smooth surface; small wavelets; well-developed waves; and rough flow. The second series showed the following sequence: smooth bed; flow-aligned ridge and trough pattern; combined ridge and rhomboid pattern; and rhomboid configuration. The third series demonstrated transverse segregation of the bed material across the ridges.- from Authors

  7. Experimental Investigation of Effects of Blockage and Free Surface Proximity on Flow-field and Performance of a Hydrokinetic Turbine

    NASA Astrophysics Data System (ADS)

    Kolekar, Nitin; Banerjee, Arindam

    2013-11-01

    Results from an experimental study to investigate the effect of blockage and free surface proximity on the performance of a constant chord, zero twist, fixed pitch hydro kinetic turbine in an open surface water channel will be presented. The presence of free surface and the size of turbine relative to the flow channel (blockage effect) affects the fluid dynamics around and in the near wake of turbine and hence the thrust-torque loading on turbine blades. Detailed parametric studies will be carried out to understand the effect of free surface proximity, Froude number (which depends on water velocity and depth of the channel), turbine proximity to channel walls and blockage on the turbine performance. Characterization of wake meandering and flow around the turbine is performed using a stereo-Particle Image Velocimetry technique for flows with various Froude number. The thrust and torque on turbine will be measured using a submerged thrust-torque sensor in-line with the turbine. The results of experiments will be compared with analytical models based on blade element momentum theory by modeling free surface and blockage effects. The authors gratefully acknowledge the financial support from the Office of Naval Research through contract ONR N000141010923.

  8. Experimental free-surface instability growth in gravity-driven film flows of Newtonian and non-Newtonian liquids

    NASA Astrophysics Data System (ADS)

    Olander, Jeffrey; Camassa, Roberto; Forest, M. Gregory; Ogrosky, H. Reed

    2015-11-01

    We present experiments on the growth of free-surface instabilities for Newtonian and viscoelastic film flow in a tube. The liquids used were a Newtonian silicone oil and various concentrations of elastic Boger fluids. The test liquids were injected axisymmetrically into a vertical glass tube at constant volume flow rate and the evolution of the free surface was observed as the film flowed down the tube due to gravity. The range of film thicknesses which exhibited instability growth was smaller for Boger fluids than for silicone oil. Long-wave modeling studies of related problems will be compared with the experimental observations, and our test fluids' rheology and potential mechanisms for the observed instability growth will be discussed.

  9. [Effect of free surface flow wetland and subsurface flow wetland on bacterial diversity in Beijing Cuihu Wetland Park].

    PubMed

    Wang, Xiao-dan; Zhai, Zhen-hua; Zhao, Shuang; Li, Rong-qi; Ma, Wen-lin; Li, Yan-hong

    2009-01-01

    To achieve the effects of artificial wetland on the bacterial diversity, the culturable bacteria and total cell counts of three wetland cells, including sewage pond (SP), free surface wetland (SF) and subsurface flow wetland (SSF), were investigated using the traditional culture-dependent approach and flow cytometry method, based on the detecting the water quality. The bacterial diversity and dominant groups were also compared by PCR-DGGE profiles and 16S rDNA library technique based on its V3 region. Results show that SF and SSF cells can remove the nutrients effectively, the highest removal ratio of COD, total nitrogen, and total phosphorus reach to 42.33%, 52.92% and 41.4%, respectively; The total microbes are increased continuously with the treatment by SF and SSF, and the culturable bacteria clones are decreased after treatment by SF, and increased after further train by SSF. The Shannon-Weaver index is increased to 3.2850 from 3.0819 while the water flowing through SF, but decreased to 3.0181 after flowing through SSF; The dominant groups in SP include Actinobacteria, Cyanobacteria and alpha-Proteobacteria, reach to 38%, 18% and 18%, respectively; but the most dominant bacteria is changed to beta-Proteobacteria with the ratio of 32% and 44%, after treatment by SF and SSF, respectively. Cytophagal Flexibacter/Bacteroides (CFB) phylum is also increased to 24% finally. Therefore, while the Cuihu Wetland removing the nutrients,the bacterial counts, diversity and dominant groups are also changed,some beneficial bacteria in beta-Proteobacteria and CFB phylum increased, and part of those deleterious bacteria in Actinobacteria and Cyanobacteria decreased.

  10. An explicit Lagrangian finite element method for free-surface weakly compressible flows

    NASA Astrophysics Data System (ADS)

    Cremonesi, Massimiliano; Meduri, Simone; Perego, Umberto; Frangi, Attilio

    2016-07-01

    In the present work, an explicit finite element approach to the solution of the Lagrangian formulation of the Navier-Stokes equations for weakly compressible fluids or fluid-like materials is investigated. The introduction of a small amount of compressibility is shown to allow for the formulation of a fast and robust explicit solver based on a particle finite element method. Newtonian and Non-Newtonian Bingham laws are considered. A barotropic equation of state completes the model relating pressure and density fields. The approach has been validated through comparison with experimental tests and numerical simulations of free surface fluid problems involving water and water-soil mixtures.

  11. Experimental study of thermocapillary flows in a thin liquid layer with heat fluxes imposed on the free surface

    NASA Technical Reports Server (NTRS)

    Lai, Chun-Liang; Greenberg, Paul S.; Chai, An-Ti

    1988-01-01

    To study thermocapillary flows in a two-dimensional thin liquid layer with heat fluxes imposed on the free surface experimentally, a long tray configuration was employed to simulate the infinite layer. The surface temperature distribution due to thermocapillary convective for different flow regimes was measured and compared with theoretical predictions. A short tray configuration was also employed to study the end wall effects (insulating or conducting). The results show that for a strong convection flow with an insulating wall as the boundary the surface temperature distribution became quite uniform. Consequently, the thermocapillary driving force was greatly reduced. On the other hand, a strong fluid motion always existed adjacent to the conducting wall because of the large surface temperature gradient near the wall.

  12. Experimental study of thermocapillary flows in a thin liquid layer with heat fluxes imposed on the free surface

    NASA Technical Reports Server (NTRS)

    Lai, Chun-Liang; Greenberg, Paul S.; Chai, An-Ti

    1988-01-01

    To study thermocapillary flows in a two-dimensional thin liquid layer with heat fluxes imposed on the free surface experimentally, a long tray configuration was employed to simulate the infinite layer. The surface temperature distribution due to thermocapillary convection for different flow regimes was measured and compared with theorectical predictions. A short tray configuration was also employed to study the end wall effects (insulating or conducting). The results show that, for a strong convection flow with an insulating wall as the boundary, the surface temperature distribution became quite uniform. Consequently, the thermocapillary driving force was greatly reduced. On the other hand, a strong fluid motion always existed adjacent to the conducting wall because of the large surface temperature gradient near the wall.

  13. A Finite Element Method for Free-Surface Flows of Incompressible Fluids in Three Dimensions, Part II: Dynamic Wetting Lines

    SciTech Connect

    Baer, T.A.; Cairncross, R.A.; Rao, R.R.; Sackinger, P.A.; Schunk, P.R.

    1999-01-29

    To date, few researchers have solved three-dimensional free-surface problems with dynamic wetting lines. This paper extends the free-surface finite element method described in a companion paper [Cairncross, R.A., P.R. Schunk, T.A. Baer, P.A. Sackinger, R.R. Rao, "A finite element method for free surface flows of incompressible fluid in three dimensions, Part I: Boundary-Fitted mesh motion.", to be published (1998)] to handle dynamic wetting. A generalization of the technique used in two dimensional modeling to circumvent double-valued velocities at the wetting line, the so-called kinematic paradox, is presented for a wetting line in three dimensions. This approach requires the fluid velocity normal to the contact line to be zero, the fluid velocity tangent to the contact line to be equal to the tangential component of web velocity, and the fluid velocity into the web to be zero. In addition, slip is allowed in a narrow strip along the substrate surface near the dynamic contact line. For realistic wetting-line motion, a contact angle which varies with wetting speed is required because contact lines in three dimensions typically advance or recede a different rates depending upon location and/or have both advancing and receding portions. The theory is applied to capillary rise of static fluid in a corner, the initial motion of a Newtonian droplet down an inclined plane, and extrusion of a Newtonian fluid from a nozzle onto a moving substrate. The extrusion results are compared to experimental visualization. Subject Categories

  14. Computational modeling of mold filling and related free-surface flows in shape casting: An overview of the challenges involved

    NASA Astrophysics Data System (ADS)

    Cross, M.; McBride, D.; Croft, T. N.; Williams, A. J.; Pericleous, K.; Lawrence, J. A.

    2006-12-01

    Accurate representation of the coupled effects between turbulent fluid flow with a free surface, heat transfer, solidification, and mold deformation has been shown to be necessary for the realistic prediction of several defects in castings and also for determining the final crystalline structure. A core component of the computational modeling of casting processes involves mold filling, which is the most computationally intensive aspect of casting simulation at the continuum level. Considering the complex geometries involved in shape casting, the evolution of the free surface, gas entrapment, and the entrainment of oxide layers into the casting make this a very challenging task in every respect. Despite well over 30 years of effort in developing algorithms, this is by no means a closed subject. In this article, we will review the full range of computational methods used, from unstructured finite-element (FE) and finite-volume (FV) methods through fully structured and block-structured approaches utilizing the cut-cell family of techniques to capture the geometric complexity inherent in shape casting. This discussion will include the challenges of generating rapid solutions on high-performance parallel cluster technology and how mold filling links in with the full spectrum of physics involved in shape casting. Finally, some indications as to novel techniques emerging now that can address genuinely arbitrarily complex geometries are briefly outlined and their advantages and disadvantages are discussed.

  15. Depth-averaged analytic solutions for free-surface granular flows impacting rigid walls down inclines

    NASA Astrophysics Data System (ADS)

    Faug, Thierry

    2015-12-01

    In the present paper, flows of granular materials impacting wall-like obstacles down inclines are described by depth-averaged analytic solutions. Particular attention is paid to extending the existing depth-averaged equations initially developed for frictionless and incompressible fluids down a horizontal plane. The effects of the gravitational acceleration along the slope, and of the retarding acceleration caused by friction as well, are systematically taken into account. The analytic solutions are then used to revisit existing data on rigid walls impacted by granular flows. This approach allows establishing a complete phase diagram for granular flow-wall interaction.

  16. Determinants of modelling choices for 1-D free-surface flow and erosion issues in hydrology: a review

    NASA Astrophysics Data System (ADS)

    Cheviron, B.; Moussa, R.

    2015-09-01

    This review paper investigates the determinants of modelling choices, for numerous applications of 1-D free-surface flow and erosion equations, across multiple spatiotemporal scales. We aim to characterize each case study by its signature composed of model refinement (Navier-Stokes: NS, Reynolds-Averaged Navier-Stokes: RANS, Saint-Venant: SV or Approximations of Saint-Venant: ASV), spatiotemporal scales (domain length: L from 1 cm to 1000 km; temporal scale: T from 1 second to 1 year; flow depth: H from 1 mm to 10 m), flow typology (Overland: O, High gradient: Hg, Bedforms: B, Fluvial: F) and dimensionless numbers (Dimensionless time period T*, Reynolds number Re, Froude number Fr, Slope S, Inundation ratio Λz, Shields number θ). The determinants of modelling choices are therefore sought in the interplay between flow characteristics, cross-scale and scale-independent views. The influence of spatiotemporal scales on modelling choices is first quantified through the expected correlation between increasing scales and decreasing model refinements, identifying then flow typology a secondary but mattering determinant in the choice of model refinement. This finding is confirmed by the discriminating values of several dimensionless numbers, that prove preferential associations between model refinements and flow typologies. This review is intended to help each modeller positioning his (her) choices with respect to the most frequent practices, within a generic, normative procedure possibly enriched by the community for a larger, comprehensive and updated image of modelling strategies.

  17. The pattern of surface waves in a shallow free surface flow

    NASA Astrophysics Data System (ADS)

    Horoshenkov, K. V.; Nichols, A.; Tait, S. J.; Maximov, G. A.

    2013-09-01

    This work presents new water surface elevation data including evidence of the spatial correlation of water surface waves generated in shallow water flows over a gravel bed without appreciable bed forms. Careful laboratory experiments have shown that these water surface waves are not well-known gravity or capillary waves but are caused by a different physical phenomenon. In the flow conditions studied, the shear present in shallow flows generates flow structures, which rise and impact on the water-air interface. It is shown that the spatial correlation function observed for these water surface waves can be approximated by the following analytical expression W (ρ)=e-ρ2/2σw2cos(2πL0-1ρ). The proposed approximation depends on the spatial correlation radius, σw, characteristic spatial period, L0, and spatial lag, ρ. This approximation holds for all the hydraulic conditions examined in this study. It is shown that L0 relates to the depth-averaged flow velocity and carries information on the shape of the vertical velocity profile and bed roughness. It is also shown that σw is related to the hydraulic roughness and the flow Reynolds number.

  18. Internal dynamics of a free-surface viscoplastic flow down an inclined plane: experimental results through PIV measurements

    NASA Astrophysics Data System (ADS)

    Freydier, Perrine; Chambon, Guillaume; Naaim, Mohamed

    2015-04-01

    Debris flows constitute one of the most important natural hazards throughout the mountainous regions of the world, causing significant damages and economic losses. These mass are composed of particles of all sizes from clay to boulders suspended in a viscous fluid. An important goal resides in developing models that are able to accurately predict the hydraulic properties of debris flows. First, these flows are generally represented using models based on a momentum integral approach that consists in assuming a shallow flow and in depth averaging the local conservation equations. These models take into account closure terms depending on the shape of the velocity profile inside the flow. Second, the specific migration mechanisms of the suspended particles, which have a strong influence on the propagation of the surges, also depend on the internal dynamics within the flow. However, to date, few studies concerning the internal dynamics in particular in the vicinity of the front, of such flows have been carried out. The aim of this study is to document the internal dynamics in free-surface viscoplastic flows down an inclined channel. The rheological studies concerning natural muddy debris flows, rich in fine particles, have shown that these materials can be modeled, at least as a first approximation as non-Newtonian viscoplastic fluids. Experiments are conducted in an inclined channel whose bottom is constituted by an upward-moving conveyor belt with controlled velocity. Carbopol microgel has been used as a homogeneous transparent viscoplastic fluid. This experimental setup allows generating and monitoring stationary gravity-driven surges in the laboratory frame. We use PIV technique (Particle Image Velocimetry) to obtain velocity fields both in the uniform zone and within the front zone where flow thickness is variable and where recirculation takes place. Experimental velocity profiles and determination of plug position will be presented and compared to theoretical

  19. Continuation in a parameter - Experience with viscous and free surface flows

    NASA Astrophysics Data System (ADS)

    Kheshgi, H. S.; Basaran, O. A.; Benner, R. E.; Kistler, S. F.; Scriven, L. E.

    The results of modifications in continuation methods applied to obtain solutions to the Navier-Stokes systems of equations for incompressible, two-dimensional, steady flows are reported. It is shown that parameter continuation permits prediction of accurate, initial estimates for iterative processing of nonlinear finite difference and finite element equations of motions. The new parameter steps are derived from values of the preceding parameter steps. The accuracy of the estimates is ensured with appropriate choices of the step size. The continuation predictor/iterative corrector is demonstrated to trace the branches of parameter space along which steady flow states are found, and techniques are available for tracing multiply branching paths. The techniques are applied to solving the Navier-Stokes equations for flow through a rotating square channel, the formation of a falling liquid curtain, and gyrostatic equilibria of rotating cylindrical drops.

  20. Continuation in a parameter - Experience with viscous and free surface flows

    NASA Technical Reports Server (NTRS)

    Kheshgi, H. S.; Basaran, O. A.; Benner, R. E.; Kistler, S. F.; Scriven, L. E.

    1983-01-01

    The results of modifications in continuation methods applied to obtain solutions to the Navier-Stokes systems of equations for incompressible, two-dimensional, steady flows are reported. It is shown that parameter continuation permits prediction of accurate, initial estimates for iterative processing of nonlinear finite difference and finite element equations of motions. The new parameter steps are derived from values of the preceding parameter steps. The accuracy of the estimates is ensured with appropriate choices of the step size. The continuation predictor/iterative corrector is demonstrated to trace the branches of parameter space along which steady flow states are found, and techniques are available for tracing multiply branching paths. The techniques are applied to solving the Navier-Stokes equations for flow through a rotating square channel, the formation of a falling liquid curtain, and gyrostatic equilibria of rotating cylindrical drops.

  1. Analysis of free-surface flows through energy considerations: Single-phase versus two-phase modeling

    NASA Astrophysics Data System (ADS)

    Marrone, Salvatore; Colagrossi, Andrea; Di Mascio, Andrea; Le Touzé, David

    2016-05-01

    The study of energetic free-surface flows is challenging because of the large range of interface scales involved due to multiple fragmentations and reconnections of the air-water interface with the formation of drops and bubbles. Because of their complexity the investigation of such phenomena through numerical simulation largely increased during recent years. Actually, in the last decades different numerical models have been developed to study these flows, especially in the context of particle methods. In the latter a single-phase approximation is usually adopted to reduce the computational costs and the model complexity. While it is well known that the role of air largely affects the local flow evolution, it is still not clear whether this single-phase approximation is able to predict global flow features like the evolution of the global mechanical energy dissipation. The present work is dedicated to this topic through the study of a selected problem simulated with both single-phase and two-phase models. It is shown that, interestingly, even though flow evolutions are different, energy evolutions can be similar when including or not the presence of air. This is remarkable since, in the problem considered, with the two-phase model about half of the energy is lost in the air phase while in the one-phase model the energy is mainly dissipated by cavity collapses.

  2. Analysis of free-surface flows through energy considerations: Single-phase versus two-phase modeling.

    PubMed

    Marrone, Salvatore; Colagrossi, Andrea; Di Mascio, Andrea; Le Touzé, David

    2016-05-01

    The study of energetic free-surface flows is challenging because of the large range of interface scales involved due to multiple fragmentations and reconnections of the air-water interface with the formation of drops and bubbles. Because of their complexity the investigation of such phenomena through numerical simulation largely increased during recent years. Actually, in the last decades different numerical models have been developed to study these flows, especially in the context of particle methods. In the latter a single-phase approximation is usually adopted to reduce the computational costs and the model complexity. While it is well known that the role of air largely affects the local flow evolution, it is still not clear whether this single-phase approximation is able to predict global flow features like the evolution of the global mechanical energy dissipation. The present work is dedicated to this topic through the study of a selected problem simulated with both single-phase and two-phase models. It is shown that, interestingly, even though flow evolutions are different, energy evolutions can be similar when including or not the presence of air. This is remarkable since, in the problem considered, with the two-phase model about half of the energy is lost in the air phase while in the one-phase model the energy is mainly dissipated by cavity collapses.

  3. Analysis of free-surface flows through energy considerations: Single-phase versus two-phase modeling.

    PubMed

    Marrone, Salvatore; Colagrossi, Andrea; Di Mascio, Andrea; Le Touzé, David

    2016-05-01

    The study of energetic free-surface flows is challenging because of the large range of interface scales involved due to multiple fragmentations and reconnections of the air-water interface with the formation of drops and bubbles. Because of their complexity the investigation of such phenomena through numerical simulation largely increased during recent years. Actually, in the last decades different numerical models have been developed to study these flows, especially in the context of particle methods. In the latter a single-phase approximation is usually adopted to reduce the computational costs and the model complexity. While it is well known that the role of air largely affects the local flow evolution, it is still not clear whether this single-phase approximation is able to predict global flow features like the evolution of the global mechanical energy dissipation. The present work is dedicated to this topic through the study of a selected problem simulated with both single-phase and two-phase models. It is shown that, interestingly, even though flow evolutions are different, energy evolutions can be similar when including or not the presence of air. This is remarkable since, in the problem considered, with the two-phase model about half of the energy is lost in the air phase while in the one-phase model the energy is mainly dissipated by cavity collapses. PMID:27300984

  4. Instability on the Free Surface of Superfluid He-II Induced by a Steady Heat Flow in Bulk

    NASA Astrophysics Data System (ADS)

    Remizov, I. A.; Levchenko, A. A.; Mezhov-Deglin, L. P.

    2016-06-01

    We report observations of the onset of irregular motion on a free surface of superfluid He-II induced by a quasi-stationary heat flow in a rectangular container. The container open from the top is mounted inside an optical cell partly filled with superfluid He-II. Three holes in the container walls provide free circulation of the normal and superfluid components inside and outside the container. The results of measurements are discussed in terms of the Korshunov theory (Eurphys Lett 16:673, 1991; JETP Lett 75:423, 2002) of the Kelvin-Helmholtz instability on an initially flat He-II surface induced by a relative motion of superfluid and normal components of the liquid along the surface when the counterflow velocity exceeds the threshold value. The experimental data are qualitatively consistent with the theoretical predictions (Korshunov in JETP Lett 75:423, 2002) taking into account the finite viscosity of He-II.

  5. Instability on the Free Surface of Superfluid He-II Induced by a Steady Heat Flow in Bulk

    NASA Astrophysics Data System (ADS)

    Remizov, I. A.; Levchenko, A. A.; Mezhov-Deglin, L. P.

    2016-11-01

    We report observations of the onset of irregular motion on a free surface of superfluid He-II induced by a quasi-stationary heat flow in a rectangular container. The container open from the top is mounted inside an optical cell partly filled with superfluid He-II. Three holes in the container walls provide free circulation of the normal and superfluid components inside and outside the container. The results of measurements are discussed in terms of the Korshunov theory (Eurphys Lett 16:673, 1991; JETP Lett 75:423, 2002) of the Kelvin-Helmholtz instability on an initially flat He-II surface induced by a relative motion of superfluid and normal components of the liquid along the surface when the counterflow velocity exceeds the threshold value. The experimental data are qualitatively consistent with the theoretical predictions (Korshunov in JETP Lett 75:423, 2002) taking into account the finite viscosity of He-II.

  6. Thermally excited fluid flow in a microsized liquid crystal channel with a free surface

    NASA Astrophysics Data System (ADS)

    Zakharov, A. V.; Vakulenko, A. A.

    2015-06-01

    The temperature-induced reorientation dynamics in microsized liquid crystal (LC) channel with a free LC/vacuum interface has been investigated theoretically based on the hydrodynamic theory including the director motion, the thermally excited fluid flow v, and the temperature T redistribution, produced by induced heating in the interior of the LC sample. Analysis of the numerical results shows that due to interaction between ∇T and the gradient of the director field ∇ n ˆ in the LC channel bounded by the free LC/vacuum interface, a thermally excited vortical fluid flow is maintained in the vicinity of the heat source. Calculations also show that in the case of the fast heating, the LC sample settles down to three-vortical flow regime, whereas in the case of the slow heating, the LC material settles down to bi-vortical flow regime. As for nematogenic material, we have considered the LC channel to be occupied by 4-n-pentyl-4'-cyanobiphenyl and investigated the effect of both ∇ n ˆ and ∇T on the magnitude and direction of v, as well as on the height of the LC film on the solid surface, for a number of heating and hydrodynamic regimes.

  7. Analysis of pipe flow with free surface. Part II. Theoretical analysis and experiment

    NASA Astrophysics Data System (ADS)

    Tanaka, Amane; Takaki, Ryuji

    1994-05-01

    Flow field near the front of an incompressible viscous fluid pushed into a circular pipe is analyzed theoretically and observed experimentally. In the theory, an approximated stream function for a steady state near the axis of the pipe is obtained by use of the Stokes equation. In the experiment, the shape of the surface was observed by a video camera. The theoretical velocity profile and the surface shape near the axis coincide with those from computation (Part I) and experiment.

  8. Explicit incompressible SPH algorithm for free-surface flow modelling: A comparison with weakly compressible schemes

    NASA Astrophysics Data System (ADS)

    Nomeritae; Daly, Edoardo; Grimaldi, Stefania; Bui, Ha Hong

    2016-11-01

    Several numerical schemes are available to simulate fluid flow with Smoothed Particles Hydrodynamics (SPH). Although commonly experiencing pressure fluctuations, schemes allowing for small changes in fluid density, referred to as weakly compressible (WCSPH and δ-SPH), are often used because of their faster computational time when compared to implicit incompressible schemes (IISPH). Explicit numerical schemes for incompressible fluid flow (EISPH), although more computationally efficient than IISPH, have not been largely used in the literature. To explore advantages and disadvantages of EISPH, this study compared an EISPH scheme with WCSPH and δ-SPH. The three schemes were compared for the case of still water and a wave generated by a dam-break. EISPH and δ-SPH were also compared for the case of a dam-break wave colliding with a vertical wall and a dam-break wave flowing over a wet bed. The three schemes performed similarly in reproducing theoretical and experimental results. EISPH led to results overall similar to WCSPH and δ-SPH, but with smoother pressure dynamics and faster computational times. EISPH presented some errors in the imposition of incompressibility, with the divergence of velocity being different from zero in parts of the fluid flow, especially near the surface. These errors in the divergence of velocity were comparable to the values of velocity divergence obtained with δ-SPH. In an attempt to reduce the velocity divergence in EISPH, an iterative procedure was implemented to calculate the pressure (iterative-EISPH). Although no real improvement was achieved in terms of velocity divergence, the pressure thus calculated was smoother and in some cases was closer to measured experimental values.

  9. Interfacial stress balances in structured continua and free surface flows in ferrofluids

    SciTech Connect

    Chaves, Arlex; Rinaldi, Carlos

    2014-04-15

    Interfacial linear and internal angular momentum balances are obtained for a structured continuum and for the special case of a ferrofluid, a suspension of magnetic nanoparticles in a Newtonian fluid. The interfacial balance equations account for the effects of surface tension and surface tension gradient, magnetic surface excess forces, antisymmetric stresses, and couple stresses in driving interfacial flows in ferrofluids. Application of the interfacial balance equations is illustrated by obtaining analytical expressions for the translational and spin velocity profiles in a thin film of ferrofluid on an infinite flat plate when a rotating magnetic field is applied with axis of rotation parallel to the ferrofluid/air interface. The cases of zero and non-zero spin viscosity are considered for small applied magnetic field amplitude. Expressions for the maximum translational velocity, slope of the translational velocity profile at the ferrofluid/air interface, and volumetric flow rate are obtained and their use to test the relevance of spin viscosity and couple stresses in the flow situation under consideration is discussed.

  10. Interfacial stress balances in structured continua and free surface flows in ferrofluids

    NASA Astrophysics Data System (ADS)

    Chaves, Arlex; Rinaldi, Carlos

    2014-04-01

    Interfacial linear and internal angular momentum balances are obtained for a structured continuum and for the special case of a ferrofluid, a suspension of magnetic nanoparticles in a Newtonian fluid. The interfacial balance equations account for the effects of surface tension and surface tension gradient, magnetic surface excess forces, antisymmetric stresses, and couple stresses in driving interfacial flows in ferrofluids. Application of the interfacial balance equations is illustrated by obtaining analytical expressions for the translational and spin velocity profiles in a thin film of ferrofluid on an infinite flat plate when a rotating magnetic field is applied with axis of rotation parallel to the ferrofluid/air interface. The cases of zero and non-zero spin viscosity are considered for small applied magnetic field amplitude. Expressions for the maximum translational velocity, slope of the translational velocity profile at the ferrofluid/air interface, and volumetric flow rate are obtained and their use to test the relevance of spin viscosity and couple stresses in the flow situation under consideration is discussed.

  11. Simulation of the 3D viscoelastic free surface flow by a parallel corrected particle scheme

    NASA Astrophysics Data System (ADS)

    Jin-Lian, Ren; Tao, Jiang

    2016-02-01

    In this work, the behavior of the three-dimensional (3D) jet coiling based on the viscoelastic Oldroyd-B model is investigated by a corrected particle scheme, which is named the smoothed particle hydrodynamics with corrected symmetric kernel gradient and shifting particle technique (SPH_CS_SP) method. The accuracy and stability of SPH_CS_SP method is first tested by solving Poiseuille flow and Taylor-Green flow. Then the capacity for the SPH_CS_SP method to solve the viscoelastic fluid is verified by the polymer flow through a periodic array of cylinders. Moreover, the convergence of the SPH_CS_SP method is also investigated. Finally, the proposed method is further applied to the 3D viscoelastic jet coiling problem, and the influences of macroscopic parameters on the jet coiling are discussed. The numerical results show that the SPH_CS_SP method has higher accuracy and better stability than the traditional SPH method and other corrected SPH method, and can improve the tensile instability. Project supported by the Natural Science Foundation of Jiangsu Province, China (Grant Nos. BK20130436 and BK20150436) and the Natural Science Foundation of the Higher Education Institutions of Jiangsu Province, China (Grant No. 15KJB110025).

  12. SPH-DCDEM model for arbitrary geometries in free surface solid-fluid flows

    NASA Astrophysics Data System (ADS)

    Canelas, Ricardo B.; Crespo, Alejandro J. C.; Domínguez, Jose M.; Ferreira, Rui M. L.; Gómez-Gesteira, Moncho

    2016-05-01

    A unified discretization of rigid solids and fluids is introduced, allowing for resolved simulations of fluid-solid phases within a meshless framework. The numerical solution, attained by Smoothed Particle Hydrodynamics (SPH) and a variation of Discrete Element Method (DEM), the Distributed Contact Discrete Element Method (DCDEM) discretization, is achieved by directly considering solid-solid and solid-fluid interactions. The novelty of the work is centred on the generalization of the coupling of the DEM and SPH methodologies for resolved simulations, allowing for state-of-the-art contact mechanics theories to be used in arbitrary geometries, while fluid to solid and vice versa momentum transfers are accurately described. The methods are introduced, analysed and discussed. Initial validations on the DCDEM and the fluid coupling are presented, drawing from test cases in the literature. An experimental campaign serves as a validation point for complex, large scale solid-fluid flows, where a set of blocks in several configurations is subjected to a dam-break wave. Blocks are tracked and positions are then compared between experimental data and the numerical solutions. A Particle Image Velocimetry (PIV) technique allows for the quantification of the flow field and direct comparison with numerical data. The results show that the model is accurate and is capable of treating highly complex interactions, such as transport of debris or hydrodynamic actions on structures, if relevant scales are reproduced.

  13. A numerical study on the evolution and structure of a stress-driven free-surface turbulent shear flow

    NASA Astrophysics Data System (ADS)

    Tsai, Wu-Ting; Chen, Shi-Ming; Moeng, Chin-Hoh

    2005-12-01

    Turbulent shear flow beneath a flat free surface driven by a surface stress is simulated numerically to gain a better understanding of the hydrodynamic processes governing the scalar transfer across the air-water interface. The simulation is posed to mimic the subsequent development of a wind-driven shear layer as in a previous experiment except that the initiation of the surface waves is inhibited, thus focusing on the boundary effect of the stress-imposed surface on the underlying turbulent flow and vice versa. Despite the idealizations inherent in conducting the simulation, the computed flow exhibits the major surface features, qualitatively similar to those that appear in the laboratory and field experiments. Two distinct surface signatures, namely elongated high-speed streaks and localized low-speed spots, are observed in the simulated flow. Including temperature as a passive tracer and describing an upward heat flux at the surface, we obtain high-speed streaks that are colder and low-speed spots that are warmer than the surrounding regions. The high-speed streaks, arranged with somewhat equal cross-spacing of centimetres scale, are formed by an array of streamwise jets within the viscous sublayer immediately next to the surface. Beneath the streaks, counter-rotating streamwise vortex pairs are observed among other prevailing elongated vortices. However, they are significantly shorter in length and more irregular than their corresponding high-speed streaks at the surface. Accompanying the more organized high-speed streaks, localized regions of low streamwise velocity emerge randomly on the surface. These low-speed spots are attributed to strong upwelling flows which disrupt the viscous sublayer and also bring up the submerged fluids of low streamwise velocity. The occasional interruptions of the streamwise high-speed jets by the upwelling flows account for bifurcation or dislocation of the surface streaks. Statistics of the turbulence are presented and their

  14. Determinants of modelling choices for 1-D free-surface flow and morphodynamics in hydrology and hydraulics: a review

    NASA Astrophysics Data System (ADS)

    Cheviron, Bruno; Moussa, Roger

    2016-09-01

    This review paper investigates the determinants of modelling choices, for numerous applications of 1-D free-surface flow and morphodynamic equations in hydrology and hydraulics, across multiple spatiotemporal scales. We aim to characterize each case study by its signature composed of model refinement (Navier-Stokes: NS; Reynolds-averaged Navier-Stokes: RANS; Saint-Venant: SV; or approximations to Saint-Venant: ASV), spatiotemporal scales and subscales (domain length: L from 1 cm to 1000 km; temporal scale: T from 1 s to 1 year; flow depth: H from 1 mm to 10 m; spatial step for modelling: δL; temporal step: δT), flow typology (Overland: O; High gradient: Hg; Bedforms: B; Fluvial: F), and dimensionless numbers (dimensionless time period T*, Reynolds number Re, Froude number Fr, slope S, inundation ratio Λz, Shields number θ). The determinants of modelling choices are therefore sought in the interplay between flow characteristics and cross-scale and scale-independent views. The influence of spatiotemporal scales on modelling choices is first quantified through the expected correlation between increasing scales and decreasing model refinements (though modelling objectives also show through the chosen spatial and temporal subscales). Then flow typology appears a secondary but important determinant in the choice of model refinement. This finding is confirmed by the discriminating values of several dimensionless numbers, which prove preferential associations between model refinements and flow typologies. This review is intended to help modellers in positioning their choices with respect to the most frequent practices, within a generic, normative procedure possibly enriched by the community for a larger, comprehensive and updated image of modelling strategies.

  15. Plane stokes flow driven by capillarity on a free surface: Overview and status

    SciTech Connect

    Hopper, R.W.

    1991-10-25

    This article summarizes some recent work on the creeping viscous incompressible plane flow in a region, bounded by a simple smooth closed curve and driven solely by surface tension. Such problems are self-contained in that the applied tractions are intrinsic in the geometry. The objective is to determine exactly the time evolution of the shape of the region. The problems are fundamentally nonlinear due to the large changes in shape, and it is emphasized that no mathematical approximations are made. For finite regions, the shape in the complex z-plane is described in terms of a time-dependent conformal mapping function {Omega}({zeta}, t) on the fixed region {vert bar} {zeta} {vert bar} {le} 1 of the complex {zeta}-plane. In practice, it has been necessary to conjecture an explicit parametric form {Omega}({zeta};{alpha}{sub 1}(t), {alpha}{sub 2}(t), {hor ellipsis}) whose validity must be verified using the shape- evolution equation. Suitable parameterizations are not always obvious. When the conjectured form holds and the equations can be solved, the evolution of the shape with time is obtained in simple, exact and closed form except for the value of the time, which requires a mere quadrature. Internal velocity and stress fields can be obtained.

  16. Plane stokes flow driven by capillarity on a free surface: Overview and status. Revision 2

    SciTech Connect

    Hopper, R.W.

    1991-10-25

    This article summarizes some recent work on the creeping viscous incompressible plane flow in a region, bounded by a simple smooth closed curve and driven solely by surface tension. Such problems are self-contained in that the applied tractions are intrinsic in the geometry. The objective is to determine exactly the time evolution of the shape of the region. The problems are fundamentally nonlinear due to the large changes in shape, and it is emphasized that no mathematical approximations are made. For finite regions, the shape in the complex z-plane is described in terms of a time-dependent conformal mapping function {Omega}({zeta}, t) on the fixed region {vert_bar} {zeta} {vert_bar} {le} 1 of the complex {zeta}-plane. In practice, it has been necessary to conjecture an explicit parametric form {Omega}[{zeta};{alpha}{sub 1}(t), {alpha}{sub 2}(t), {hor_ellipsis}] whose validity must be verified using the shape- evolution equation. Suitable parameterizations are not always obvious. When the conjectured form holds and the equations can be solved, the evolution of the shape with time is obtained in simple, exact and closed form except for the value of the time, which requires a mere quadrature. Internal velocity and stress fields can be obtained.

  17. A closure-independent Generalized Roe solver for free-surface, two-phase flows over mobile bed

    NASA Astrophysics Data System (ADS)

    Rosatti, Giorgio; Begnudelli, Lorenzo

    2013-12-01

    Several different natural phenomena can be studied in the framework of free-surface, two-phase flows over mobile bed. Mathematically, they can be described by the same set of highly nonlinear, hyperbolic nonconservative PDEs but they differ in the possible algebraic closure relations. These affect significantly the relevant eigenvalues and consequently, all finite-volume numerical methods based on upwind Godunov-type fluxes. In this work the Generalized Roe solver, introduced in [29] for the case of a specific closure, is reformulated in a complete closure-independent way. This gives the solver a quite general applicability to the class of problems previously mentioned. Moreover, the new method maintains all the desirable features shown by the original one: full two-dimensionality and exact well-balanceness. This result is made possible thanks to the development of a novel Multiple Averages (MAs) approach that allows a straightforward determination of the matrices required by the solver. Several tests show the capabilities of the proposed numerical strategy.

  18. Statistical analysis of turbulent super-streamwise vortices based on observations of streaky structures near the free surface in the smooth open channel flow

    NASA Astrophysics Data System (ADS)

    Zhong, Qiang; Chen, Qigang; Wang, Hao; Li, Danxun; Wang, Xingkui

    2016-05-01

    Long streamwise-elongated high- and low-speed streaks are repeatedly observed near the free surface in open channel flows in natural rivers and lab experiments. Super-streamwise vortex model has been proposed to explain this widespread phenomenon for quite some time. However, statistical evidence of the existence of the super-streamwise vortices as one type of coherent structures is still insufficient. Correlation and proper orthogonal decomposition (POD) analysis based on PIV experimental data in the streamwise-spanwise plane near the free surface in a smooth open channel flow are employed to investigate this topic. Correlation analysis revealed that the streaky structures appear frequently near the free surface and their occurrence probability at any spanwise position is equal. The spanwise velocity fluctuation usually flows from low-speed streaks toward high-speed streaks. The average spanwise width and spacing between neighboring low (or high) speed streaks are approximately h and 2h respectively. POD analysis reveals that there are streaks with different spanwise width in the instantaneous flow fields. Typical streamwise rotational movement can be sketched out directly based on the results from statistical analyses. Point-by-point analysis indicates that this pattern is consistent everywhere in the measurement window and is without any inhomogeneity in the spanwise direction, which reveals the essential difference between coherent structures and secondary flow cells. The pattern found by statistical analysis is consistent with the notion that the super-streamwise vortices exist universally as one type of coherent structure in open channel flows.

  19. Application of the methods of gas dynamics to water flows with free surface I : flows with no energy dissipation

    NASA Technical Reports Server (NTRS)

    Preiswerk, Ernst

    1940-01-01

    The application is treated in sufficient detail to facilitate as much as possible its application by the engineer who is less familiar with the subject. The present work was undertaken with two objects in view. In the first place, it is considered as a contribution to the water analogy of gas flows, and secondly, a large portion is devoted to the general theory of the two-dimensional supersonic flows.

  20. A finite difference technique for solving a time strain separable K-BKZ constitutive equation for two-dimensional moving free surface flows

    NASA Astrophysics Data System (ADS)

    Tomé, M. F.; Bertoco, J.; Oishi, C. M.; Araujo, M. S. B.; Cruz, D.; Pinho, F. T.; Vynnycky, M.

    2016-04-01

    This work is concerned with the numerical solution of the K-BKZ integral constitutive equation for two-dimensional time-dependent free surface flows. The numerical method proposed herein is a finite difference technique for simulating flows possessing moving surfaces that can interact with solid walls. The main characteristics of the methodology employed are: the momentum and mass conservation equations are solved by an implicit method; the pressure boundary condition on the free surface is implicitly coupled with the Poisson equation for obtaining the pressure field from mass conservation; a novel scheme for defining the past times t‧ is employed; the Finger tensor is calculated by the deformation fields method and is advanced in time by a second-order Runge-Kutta method. This new technique is verified by solving shear and uniaxial elongational flows. Furthermore, an analytic solution for fully developed channel flow is obtained that is employed in the verification and assessment of convergence with mesh refinement of the numerical solution. For free surface flows, the assessment of convergence with mesh refinement relies on a jet impinging on a rigid surface and a comparison of the simulation of a extrudate swell problem studied by Mitsoulis (2010) [44] was performed. Finally, the new code is used to investigate in detail the jet buckling phenomenon of K-BKZ fluids.

  1. Application of the Methods of Gas Dynamics to Water Flows with Free Surface II : Flows with Momentum Discontinuities (hydraulic Jumps)

    NASA Technical Reports Server (NTRS)

    Preiswerk, Ernst

    1940-01-01

    In this paper an introduction to shock polar diagrams is given which then leads into an examination of water depths in hydraulic jumps. Energy loss during these jumps is considered along with an extended look at elementary solutions of flow. An experimental test set-up is described and the results presented.

  2. A numerical study of steady 2D flow around NACA 0015 and NACA 0012 hydrofoil with free surface using VOF method

    NASA Astrophysics Data System (ADS)

    Adjali, Saadia; Belkadi, Mustapha; Aounallah, Mohammed; Imine, Omar

    2015-05-01

    Accurate simulation of turbulent free surface flows around surface ships has a central role in the optimal design of such naval vessels. The flow problem to be simulated is rich in complexity and poses many modeling challenges because of the existence of breaking waves around the ship hull, and because of the interaction of the two-phase flow with the turbulent boundary layer. In this paper, our goal is to estimate the lift and drag coefficients for NACA 0012 of hydrofoil advancing in calm water under steady conditions with free surface and emerged NACA 0015. The commercial CFD software FLUENT version 14 is used for the computations in the present study. The calculated grid is established using the code computer GAMBIT 2.3.26.The shear stress k-ωSST model is used for turbulence modeling and the volume of fluid technique is employed to simulate the free-surface motion. In this computation, the second order upwind scheme is used for discretizing the convection terms in the momentum transport equations, the Modified HRIC scheme for VOF discretisation. The results obtained compare well with the experimental data.

  3. Lithium-Based High Energy Density Flow Batteries

    NASA Technical Reports Server (NTRS)

    Bugga, Ratnakumar V. (Inventor); West, William C. (Inventor); Kindler, Andrew (Inventor); Smart, Marshall C. (Inventor)

    2014-01-01

    Systems and methods in accordance with embodiments of the invention implement a lithium-based high energy density flow battery. In one embodiment, a lithium-based high energy density flow battery includes a first anodic conductive solution that includes a lithium polyaromatic hydrocarbon complex dissolved in a solvent, a second cathodic conductive solution that includes a cathodic complex dissolved in a solvent, a solid lithium ion conductor disposed so as to separate the first solution from the second solution, such that the first conductive solution, the second conductive solution, and the solid lithium ionic conductor define a circuit, where when the circuit is closed, lithium from the lithium polyaromatic hydrocarbon complex in the first conductive solution dissociates from the lithium polyaromatic hydrocarbon complex, migrates through the solid lithium ionic conductor, and associates with the cathodic complex of the second conductive solution, and a current is generated.

  4. Lithium-Polysulfide Flow Battery Demonstration

    SciTech Connect

    Zheng, Wesley

    2014-06-30

    In this video, Stanford graduate student Wesley Zheng demonstrates the new low-cost, long-lived flow battery he helped create. The researchers created this miniature system using simple glassware. Adding a lithium polysulfide solution to the flask immediately produces electricity that lights an LED. A utility version of the new battery would be scaled up to store many megawatt-hours of energy.

  5. Lithium-Polysulfide Flow Battery Demonstration

    ScienceCinema

    Zheng, Wesley

    2016-07-12

    In this video, Stanford graduate student Wesley Zheng demonstrates the new low-cost, long-lived flow battery he helped create. The researchers created this miniature system using simple glassware. Adding a lithium polysulfide solution to the flask immediately produces electricity that lights an LED. A utility version of the new battery would be scaled up to store many megawatt-hours of energy.

  6. On the effect of standard PFEM remeshing on volume conservation in free-surface fluid flow problems

    NASA Astrophysics Data System (ADS)

    Franci, Alessandro; Cremonesi, Massimiliano

    2016-07-01

    The aim of this work is to analyze the remeshing procedure used in the particle finite element method (PFEM) and to investigate how this operation may affect the numerical results. The PFEM remeshing algorithm combines the Delaunay triangulation and the Alpha Shape method to guarantee a good quality of the Lagrangian mesh also in large deformation processes. However, this strategy may lead to local variations of the topology that may cause an artificial change of the global volume. The issue of volume conservation is here studied in detail. An accurate description of all the situations that may induce a volume variation during the PFEM regeneration of the mesh is provided. Moreover, the crucial role of the parameter α used in the Alpha Shape method is highlighted and a range of values of α for which the differences between the numerical results are negligible, is found. Furthermore, it is shown that the variation of volume induced by the remeshing reduces by refining the mesh. This check of convergence is of paramount importance for the reliability of the PFEM. The study is carried out for 2D free-surface fluid dynamics problems, however the conclusions can be extended to 3D and to all those problems characterized by significant variations of internal and external boundaries.

  7. Turbulence of a Free Surface

    SciTech Connect

    Savelsberg, Ralph; Water, Willem van de

    2008-01-25

    We study the free surface of a turbulent channel flow, in particular, the relation between the statistical properties of the wrinkled surface and those of the velocity field beneath it. For an irregular flow shed off a vertical cylinder, surface indentations are strongly correlated with vortices in the subsurface flow. For fully developed turbulence this correlation is dramatically reduced. This is because the large eddies excite random capillary-gravity waves that travel in all directions across the surface. Both their predominant wavelength and their anisotropy are determined by the subsurface turbulence.

  8. Turbulence of a free surface.

    PubMed

    Savelsberg, Ralph; van de Water, Willem

    2008-01-25

    We study the free surface of a turbulent channel flow, in particular, the relation between the statistical properties of the wrinkled surface and those of the velocity field beneath it. For an irregular flow shed off a vertical cylinder, surface indentations are strongly correlated with vortices in the subsurface flow. For fully developed turbulence this correlation is dramatically reduced. This is because the large eddies excite random capillary-gravity waves that travel in all directions across the surface. Both their predominant wavelength and their anisotropy are determined by the subsurface turbulence. PMID:18232984

  9. Morphological instability of the solid-liquid interface under a thin shear flow with a free surface-ripples on icicles and stalactites

    NASA Astrophysics Data System (ADS)

    Ueno, Kazuto

    2007-03-01

    Icicles and stalactites grow when their surfaces are covered with a thin film of flowing water through which latent heat of fusion and carbon dioxide are released to the surrounding air by diffusion and convection. Despite the complete difference in their basic growth mechanism, their surfaces often have ripples of centimeter-scale wavelengths. We consider the underlying common mechanism of ripple formation and find that the mean thickness of the water film and the capillary length associated with the surface tension of the water-air surface are common important characteristic lengths in determining the centimeter-scale wavelength of ripples. This is the first theoretical work on the morphological instability of solidification front during icicle and stalactite growth from a thin shear flow with one side being a free surface, in which we take into account the change of shape of the water-air surface when the shape of the solid-liquid interface is changed.

  10. Numerical investigation of oscillatory thermocapillary flows under zero gravity in a circular liquid film with concave free surfaces

    NASA Astrophysics Data System (ADS)

    Yamamoto, T.; Takagi, Y.; Okano, Y.; Dost, S.

    2016-03-01

    NASA astronaut Pettit has conducted thermocapillary flow experiments in water films suspended in a solid ring onboard the International Space Station (ISS) in 2003 and 2011. In one of these experiments, an oscillatory thermocapillary flow was observed. The developed flow broke its symmetry along the centerline of the film. To the best of our knowledge, there are no studies on such oscillatory thermocapillary flows in thin films, and the flow-mechanism giving rise to such oscillatory flows is also not well understood. In order to shed light on the subject, we have carried out a numerical simulation study. The simulation results have shown that the water film geometry (film surface shape; being concave) is an important parameter and give rise to three oscillatory flow structures in the film, namely, a hydrothermal wave developing near the heated section, a symmetric oscillatory flow due to temperature variations, and a symmetry breaking flow due to the hydrodynamic instability along the free boundary layer (mixing layer) and the development of the hydrothermal waves. Simulation results show that the symmetry-breaking phenomenon observed in the thin film experiment on the ISS can be explained by the hydrodynamic instability and the development of hydrothermal waves.

  11. Computational and theoretical analysis of free surface flow in a thin liquid film under zero and normal gravity

    NASA Technical Reports Server (NTRS)

    Faghri, Amir; Swanson, Theodore D.

    1988-01-01

    The results of a numerical computation and theoretical analysis are presented for the flow of a thin liquid film in the presence and absence of a gravitational body force. Five different flow systems were used. Also presented are the governing equations and boundary conditions for the situation of a thin liquid emanating from a pressure vessel; traveling along a horizontal plate with a constant initial height and uniform initial velocity; and traveling radially along a horizontal disk with a constant initial height and uniform initial velocity.

  12. A low diffusive Lagrange-remap scheme for the simulation of violent ai-water free-surface flows

    NASA Astrophysics Data System (ADS)

    Bernard-Champmartin, Aude; De Vuyst, Florian

    2014-10-01

    In 2002, Després and Lagoutière [17] proposed a low-diffusive advection scheme for pure transport equation problems, which is particularly accurate for step-shaped solutions, and thus suited for interface tracking procedure by a color function. This has been extended by Kokh and Lagoutière [28] in the context of compressible multifluid flows using a five-equation model. In this paper, we explore a simplified variant approach for gas-liquid three-equation models. The Eulerian numerical scheme has two ingredients: a robust remapped Lagrange solver for the solution of the volume-averaged equations, and a low diffusive compressive scheme for the advection of the gas mass fraction. Numerical experiments show the performance of the computational approach on various flow reference problems: dam break, sloshing of a tank filled with water, wate-water impact and finally a case of Rayleigh-Taylor instability. One of the advantages of the present interface capturing solver is its natural implementation on parallel processors or computers. wave formation and wave breaking; wall wave impacts, local pressure peaks and pressure loadings; formation of air pockets; ejection, fragmentation of liquid droplets; Archimedes buoyancy effect with rising of bubbles and fall of droplets; effects of gas compressibility inducing a gas-to-liquid response by a pressure wave, etc. In this paper, we consider immiscible gas-liquid two-phase flow problems. The strong ratio of mass density between gas and liquid (typically 1:1000) is known to be a source of numerical stiffness and numerical instability. Therefore robust computational approaches supporting high density ratio have to be considered. Among the family of conservative Finite Volume methods (FVM), the Lagrange-remapped solvers (see e.g. [42,45,6,4,25,2]) provide both robustness and stability with achievement of mathematical properties of positiveness and entropy compatibility.Lagrange-remap numerical schemes (also referred to as Eule

  13. Simulation of Free Surface Dynamic in a Random Heterogeneous Porous Medium by the Method Based on Mapping the Regular Domain on the Flow Domain.

    NASA Astrophysics Data System (ADS)

    Lazarev, Y.; Petrov, P.; Tartakovsky, D. M.

    2002-12-01

    In this paper the problem of vacuum-incompressible fluid interface moving in a porous medium by treating conductivity of a medium as a random field with known statistics is considered. The flow is described by a combination of mass conservation and Darcy' law. The use of a coordinate system tied with the moving fluid allows reducing the problem to the well-explored class of problems with fixed boundaries and an effective conductivity tensor instead of the initial scalar conductivity. The hydraulic head is represented as a series in powers of effective conductivity fluctuations. The applied procedure is close to the perturbation theory procedure in the amplitude of the hydraulic conductivity fluctuations ˜ K when searching the solution with accuracy up to ˜ K2 . In both cases physical quantity variance is considered to be proportional to its reason: ˜ V = A ṡ ˜ K ( A is a linear operator). Yet unlike perturbation theory, where it is considered that A depends only on undisturbed flow parameters A = A(¯ K), in the approach being used A is considered to be dependent on averaged flow parameters A = A( ¯ K,< ˜ K2 > ). Equations of the mean hydraulic head and mean flux and expressions for respective variances as well are derived in the 2-D case. For 1-D flow the derived solution agrees with the exact one within terms of σ K2 -order at any free surface fluctuations. Within this approach the free surface moving, evolution in time of the mean hydraulic head spatial distribution, mean flux and relative correlation functions are described by the set of first-order partial differential equations. The conjugate gradient method with preconditioning is proposed to be used as the general method of equation numerical solving to find hydraulic head statistic moments. The problem matrix symmetry and its positive definiteness serve the foundation of the method applicability. RFLOW code has been elaborated to solve this set of equations numerically. Testing data of the

  14. A low diffusive Lagrange-remap scheme for the simulation of violent ai-water free-surface flows

    NASA Astrophysics Data System (ADS)

    Bernard-Champmartin, Aude; De Vuyst, Florian

    2014-10-01

    In 2002, Després and Lagoutière [17] proposed a low-diffusive advection scheme for pure transport equation problems, which is particularly accurate for step-shaped solutions, and thus suited for interface tracking procedure by a color function. This has been extended by Kokh and Lagoutière [28] in the context of compressible multifluid flows using a five-equation model. In this paper, we explore a simplified variant approach for gas-liquid three-equation models. The Eulerian numerical scheme has two ingredients: a robust remapped Lagrange solver for the solution of the volume-averaged equations, and a low diffusive compressive scheme for the advection of the gas mass fraction. Numerical experiments show the performance of the computational approach on various flow reference problems: dam break, sloshing of a tank filled with water, wate-water impact and finally a case of Rayleigh-Taylor instability. One of the advantages of the present interface capturing solver is its natural implementation on parallel processors or computers. wave formation and wave breaking; wall wave impacts, local pressure peaks and pressure loadings; formation of air pockets; ejection, fragmentation of liquid droplets; Archimedes buoyancy effect with rising of bubbles and fall of droplets; effects of gas compressibility inducing a gas-to-liquid response by a pressure wave, etc. In this paper, we consider immiscible gas-liquid two-phase flow problems. The strong ratio of mass density between gas and liquid (typically 1:1000) is known to be a source of numerical stiffness and numerical instability. Therefore robust computational approaches supporting high density ratio have to be considered. Among the family of conservative Finite Volume methods (FVM), the Lagrange-remapped solvers (see e.g. [42,45,6,4,25,2]) provide both robustness and stability with achievement of mathematical properties of positiveness and entropy compatibility.Lagrange-remap numerical schemes (also referred to as Eule

  15. Free surface calculations in mantle convection

    NASA Astrophysics Data System (ADS)

    Rose, I.; Buffett, B. A.; Heister, T.

    2015-12-01

    Geodynamic simulations increasingly rely on simulations with a true free surface to investigate questions of dynamic topography, tectonic deformation, gravity perturbations, and global mantle convection. However, implementations of free surface boundary conditions have proven challenging from a standpoint of accuracy, robustness, and stability. In particular, free surfaces tend to suffer from sloshing instabilities, also known as the "drunken sailor" instability, which severely limit time step sizes. Several schemes have been proposed in the literature to deal with these instabilities. Here we analyze the problem of creeping viscous flow with a free surface and discuss the origin of these instabilities. We demonstrate their cause and how existing stabilization schemes work to damp them out. Our analysis is based on formulating a generalized eigenvalue problem for the relaxation spectra of the linearized free surface problem. We also propose a new scheme for removing instabilites from free surface calculations. It does not require modifications to the system matrix, nor additional variables, but is instead an explicit scheme based on nonstandard finite differences. It relies on a single stabilization parameter which may be identified with the smallest relaxation timescale of the free surface. We analyze the stability and accuracy of the nonstandard finite difference scheme, and describe its implementation in the open source mantle convection software Aspect. We also provide comparisons between the nonstandard finite difference scheme and the quasi-implicit scheme proposed by Kaus, Muhlhaus, and May (2010).

  16. Fluid Dynamics with Free Surfaces

    1992-02-01

    RIPPLE is a two-dimensional, transient, free surface incompressible fluid dynamics program. It allows multiple free surfaces with surface tension and wall adhesion forces and has a partial cell treatment which allows curved boundaries and interior obstacles.

  17. Implicit solution of Stokes flow equation with material transport: toward thermal convection simulation under the self-gravitating field with free surface

    NASA Astrophysics Data System (ADS)

    Furuichi, M.; Nakagawa, T.; May, D.

    2013-12-01

    Stabilizing a numerical oscillation in free surface treatment is chagrining topic for a geodynamics simulation [e.g. Kaus et al. 2010, Duretz et al., 2011]. It is especially important for the Stokes flow simulation under the self-gravitating field based on 'Spherical Cartesian' method [Gerya et al., 2007], which is useful for simulating a long time scale dynamics of sinking metal rich materials to construct planetary core. The conventional explicit time stepping algorithm, which solves Stokes flow equation for a given material distribution at a previous time step, however has a difficulty for simulating dynamics such as a thermal convection, after the construction of layered structure in the planetary interior because of numerical oscillation. One effective approach for such numerically problematic behavior is an implicit treatment of advection term. In this study, three types of implicit strategy are discussed. First is the full implicit treatment with iterative non-linear solver which uses transported density by maker-in-cell method as nonlinear update. The maker-in-cell method is commonly used as low diffusive advection method, but is computationally expensive with makers to mesh interpolation. Second approach uses semi-Lagrangian method for nonlinear update instead of the maker-in-cell method to reduce computational cost. Third approach is to solve the Stokes flow equation combined with the linearized advection term in central-difference discretization to avoid the nonlinear update by the transport. In the second and third algorithms, physical value at the next time step is still transported by low diffusive maker-in-cell method. These three types of implicit method are examined by numerical experiment.

  18. Scale separation for multi-scale modeling of free-surface and two-phase flows with the conservative sharp interface method

    SciTech Connect

    Han, L.H. Hu, X.Y. Adams, N.A.

    2015-01-01

    In this paper we present a scale separation approach for multi-scale modeling of free-surface and two-phase flows with complex interface evolution. By performing a stimulus-response operation on the level-set function representing the interface, separation of resolvable and non-resolvable interface scales is achieved efficiently. Uniform positive and negative shifts of the level-set function are used to determine non-resolvable interface structures. Non-resolved interface structures are separated from the resolved ones and can be treated by a mixing model or a Lagrangian-particle model in order to preserve mass. Resolved interface structures are treated by the conservative sharp-interface model. Since the proposed scale separation approach does not rely on topological information, unlike in previous work, it can be implemented in a straightforward fashion into a given level set based interface model. A number of two- and three-dimensional numerical tests demonstrate that the proposed method is able to cope with complex interface variations accurately and significantly increases robustness against underresolved interface structures.

  19. Transient Shear Flow of Model Lithium Lubricating Greases

    NASA Astrophysics Data System (ADS)

    Delgado, M. A.; Franco, J. M.; Valencia, C.; Kuhn, E.; Gallegos, C.

    2008-07-01

    This work deals with the analysis of the transient shear flow behaviour of lithium lubricating greases differing in soap concentration and base oil viscosity. The shear-induced evolution of lithium grease microstructure has been studied by means of stress-growth experiments. With this aim, different lubricating grease formulations were manufactured by modifying lithium 12-hydroxystearate concentration and base oil viscosity. Different rheological parameters, related to both the elastic response and the structural breakdown of greases, have been analysed. In this sense, it has been found that the elastic properties of lithium lubricating greases were highly influenced by soap concentration and oil viscosity. Moreover, an asymptotic tendency has been found for the stress overshoot by increasing shear rate. The asymptotic values of this parameter have been correlated to the friction coefficient obtained in a ball-disc tribometer.

  20. A free surface sharpening strategy using optimization method

    NASA Astrophysics Data System (ADS)

    Song, Hongchao; Ji, Lucheng; Tu, Shuangzhang

    2015-11-01

    VOF method which consists in transporting a discontinuous marker variable is widely used to capture the free surface in computational fluid dynamics. There is numerical dissipation in simulations involving the transport of the marker. Numerical dissipation makes the free surface lose its physical nature. A free surface sharpening strategy based on optimization method is presented in the paper. The strategy can keep the location of the free surface and local mass conservation at both time, and can also keep free surface in a constant width. It is independent on the types of solvers and meshes. Two famous cases were chosen for verifying the free surface sharpening strategy performance. Results show that the strategy has a very good performance on keeping local mass conservation. The efficiency of prediction of the free surface is improved by applying the strategy. Accurate modeling of flow details such as drops can also be captured by this method.

  1. Free surface mixing with heat transfer

    SciTech Connect

    Raad, P.E.; Fadda, D.

    1997-05-23

    This study investigates the thermal mixing phenomenon as external rocking excitations are applied to a container partially filled with a thermally nonhomogeneous fluid. The aim of this work is to determine the effects of the rocking frequency on thermal mixing in free surface flows. Numerical results show that optimum mixing is achieved while rocking at the wave natural frequency of the tank where the free surface displacements are greatest. At this optimal frequency the strong mixing is observed to be highly concentrated in the area near the free surface. The interest is motivated by the desire to understand the fundamental physics as well as by the importance of current engineering applications in fields such as solar energy (collectors), environmental engineering (ponds, estuaries) aerospace (fuel tanks), electronics (thermal management), manufacturing (sand casting), and air conditioning (residential enclosures).

  2. Computational method for free surface hydrodynamics

    SciTech Connect

    Hirt, C.W.; Nichols, B.D.

    1980-01-01

    There are numerous flow phenomena in pressure vessel and piping systems that involve the dynamics of free fluid surfaces. For example, fluid interfaces must be considered during the draining or filling of tanks, in the formation and collapse of vapor bubbles, and in seismically shaken vessels that are partially filled. To aid in the analysis of these types of flow phenomena, a new technique has been developed for the computation of complicated free-surface motions. This technique is based on the concept of a local average volume of fluid (VOF) and is embodied in a computer program for two-dimensional, transient fluid flow called SOLA-VOF. The basic approach used in the VOF technique is briefly described, and compared to other free-surface methods. Specific capabilities of the SOLA-VOF program are illustrated by generic examples of bubble growth and collapse, flows of immiscible fluid mixtures, and the confinement of spilled liquids.

  3. Effect of Energetic Plasma Flux on Flowing Liquid Lithium Surfaces

    NASA Astrophysics Data System (ADS)

    Kalathiparambil, Kishor; Jung, Soonwook; Christenson, Michael; Fiflis, Peter; Xu, Wenyu; Szott, Mathew; Ruzic, David

    2014-10-01

    An operational liquid lithium system with steady state flow driven by thermo-electric magneto-hydrodynamic force and capable of constantly refreshing the plasma exposed surface have been demonstrated at U of I. To evaluate the system performance in reactor relevant conditions, specifically to understand the effect of disruptive plasma events on the performance of the liquid metal PFCs, the setup was integrated to a pulsed plasma generator. A coaxial plasma generator drives the plasma towards a theta pinch which preferentially heats the ions, simulating ELM like flux, and the plasma is further guided towards the target chamber which houses the flowing lithium system. The effect of the incident flux is examined using diagnostic tools including triple Langmuir probe, calorimeter, rogowski coils, Ion energy analyzers, and fast frame spectral image acquisition with specific optical filters. The plasma have been well characterized and a density of ~1021 m-3, with electron temperature ~10 - 20 eV is measured, and final plasma velocities of 34 - 74 kms-1 have been observed. Calorimetric measurements using planar molybdenum targets indicate a maximum plasma energy (with 6 kV plasma gun and 20 kV theta pinch) of 0.08 MJm-2 with plasma divergence effects resulting in marginal reduction of 40 +/- 23 J in plasma energy. Further results from the other diagnostic tools, using the flowing lithium targets and the planar targets coated with lithium will be presented. DOE DE-SC0008587.

  4. Velocity Measurements of Thermoelectric Driven Flowing Liquid Lithium

    NASA Astrophysics Data System (ADS)

    Szott, Matthew; Xu, Wenyu; Fiflis, Peter; Haehnlein, Ian; Kapat, Aveek; Kalathiparambil, Kishor; Ruzic, David N.

    2014-10-01

    Liquid lithium has garnered additional attention as a PFC due to its several advantages over solid PFCs, including reduced erosion and thermal fatigue, increased heat transfer, higher device lifetime, and enhanced plasma performance due to the establishment of low recycling regimes at the wall. The Lithium Metal Infused Trenches concept (LiMIT) has demonstrated thermoelectric magnetohydrodynamic flow of liquid lithium through horizontal open-faced metal trenches with measured velocities varying from 3.7+/-0.5 cm/s in the 1.76 T field of HT-7 to 22+/-3 cm/s in the SLiDE facility at UIUC at 0.059 T. To demonstrate the versatility of the concept, a new LiMIT design using narrower trenches shows steady state, thermoelectric-driven flow at an arbitrary angle from horizontal. Velocity characteristics are measured and discussed. Based on this LiMIT concept, a new limiter design has been developed to be tested on the mid-plane of the EAST plasma. Preliminary modelling suggests lithium flow of 6 cm/s in this device. Additionally, recent testing at the Magnum-PSI facility has given encouraging results, and velocity measurements in relation to magnetic field strength and plasma flux are also presented.

  5. Coupling a local adaptive grid refinement technique with an interface sharpening scheme for the simulation of two-phase flow and free-surface flows using VOF methodology

    NASA Astrophysics Data System (ADS)

    Malgarinos, Ilias; Nikolopoulos, Nikolaos; Gavaises, Manolis

    2015-11-01

    This study presents the implementation of an interface sharpening scheme on the basis of the Volume of Fluid (VOF) method, as well as its application in a number of theoretical and real cases usually modelled in literature. More specifically, the solution of an additional sharpening equation along with the standard VOF model equations is proposed, offering the advantage of "restraining" interface numerical diffusion, while also keeping a quite smooth induced velocity field around the interface. This sharpening equation is solved right after volume fraction advection; however a novel method for its coupling with the momentum equation has been applied in order to save computational time. The advantages of the proposed sharpening scheme lie on the facts that a) it is mass conservative thus its application does not have a negative impact on one of the most important benefits of VOF method and b) it can be used in coarser grids as now the suppression of the numerical diffusion is grid independent. The coupling of the solved equation with an adaptive local grid refinement technique is used for further decrease of computational time, while keeping high levels of accuracy at the area of maximum interest (interface). The numerical algorithm is initially tested against two theoretical benchmark cases for interface tracking methodologies followed by its validation for the case of a free-falling water droplet accelerated by gravity, as well as the normal liquid droplet impingement onto a flat substrate. Results indicate that the coupling of the interface sharpening equation with the HRIC discretization scheme used for volume fraction flux term, not only decreases the interface numerical diffusion, but also allows the induced velocity field to be less perturbed owed to spurious velocities across the liquid-gas interface. With the use of the proposed algorithmic flow path, coarser grids can replace finer ones at the slight expense of accuracy.

  6. Free surface rise and fall due to wall turbulent structures

    SciTech Connect

    Rashidi, M.

    1996-12-20

    Turbulent structures near the wall and the the surface have been studied in open channel flows using oxygen bubble visualization techniques. Experiments indicate that the flow is dominated by the generation of wall ejections and interactions of such structures with the free surface. The ejections are seen to evolve near the wall, reach the free surface, form surface patches, roll back and mix into the bulk flow. Furthermore, there are evidence of ``horseshoe`` and ``hockeystick`` type vortices in relation to the bursting events. Measurements of surface characteristics show that the ejection-inflow events are associated with deformation of the free surface. It is seen that as ejections reach the free surface, the surface goes through a rise, whereas the surface falls when the inflowing fluid returns toward the wall. These effects are enhanced as the flow Reynolds number is increased.

  7. Two-Dimensional Optical Measurement of Waves on Liquid Lithium Jet Simulating IFMIF Target Flow

    SciTech Connect

    Kazuhiro Itoh; Hiroyuki Koterazawa; Taro Itoh; Yutaka Kukita; Hiroo Kondo; Nobuo Yamaoka; Hiroshi Horiike; Mizuho Ida; Hideo Nakamura; Hiroo Nakamura; Takeo Muroga

    2006-07-01

    Waves on a liquid-lithium jet flow, simulating a proposed high-energy beam target design, have been measured using an optical technique based on specular reflection of a single laser beam on the jet surface. The stream-wise and spanwise fluctuations of the local free-surface slope were least-square fitted with a sinusoidal curve to makeup the signals lost due to the constriction in the optical arrangement. The waveform was estimated with an assumption that wave phase speed can be calculated using the dispersion relation for linear capillary-gravity waves. The direction of propagation on the jet surface was also evaluated so that the wave amplitudes, calculated by integral of slope angle signal, agree consistently in stream-wise and spanwise direction. These measurements and analyses show that the waves at the measurement location for a jet velocity of 1.2 m/s can best be represented by oblique waves with an inclination of 1.23 rad, a wavelength of 3.8 mm and a wave amplitude of about 0.05 mm. (authors)

  8. Lithium

    USGS Publications Warehouse

    Jaskula, B.W.

    2010-01-01

    In 2009, lithium consumption in the United States was estimated to have been about 1.2 kt (1,300 st) of contained lithium, a 40-percent decrease from 2008. The United States was estimated to be the fourth largest consumer of lithium, and remained the leading importer of lithium carbonate and the leading producer of value-added lithium materials. Only one company, Chemetall Foote Corp. (a subsidiary of Chemetall GmbH of Germany), produced lithium compounds from domestic resources. In 2009, world lithium consumption was estimated to have been about 18.7 kt (20,600 st) of lithium contained in minerals and compounds.

  9. Lithium

    USGS Publications Warehouse

    Jaskula, B.W.

    2011-01-01

    In 2010, lithium consumption in the United States was estimated to have been about 1 kt (1,100 st) of contained lithium, a 23-percent decrease from 2009. The United States was estimated to be the fourth largest consumer of lithium. It remained the leading importer of lithium carbonate and the leading producer of value-added lithium materials. Only one company, Chemetall Foote Corp. (a subsidiary of Chemetall GmbH of Germany), produced lithium compounds from domestic resources. In 2010, world lithium consumption was estimated to have been about 21 kt (22,000 st) of lithium contained in minerals and compounds, a 12-percent increase from 2009.

  10. Lithium

    USGS Publications Warehouse

    Jaskula, B.W.

    2012-01-01

    In 2011, world lithium consumption was estimated to have been about 25 kt (25,000 st) of lithium contained in minerals and compounds, a 10-percent increase from 2010. U.S. consumption was estimated to have been about 2 kt (2,200 st) of contained lithium, a 100-percent increase from 2010. The United States was estimated to be the fourth-ranked consumer of lithium and remained the leading importer of lithium carbonate and the leading producer of value-added lithium materials. One company, Chemetall Foote Corp. (a subsidiary of Chemetall GmbH of Germany), produced lithium compounds from domestic brine resources near Silver Peak, NV.

  11. Lithium

    USGS Publications Warehouse

    Ober, J.A.

    2006-01-01

    In 2005, lithium consumption in the United States was at 2.5 kt of contained lithium, nearly 32% more than the estimate for 2004. World consumption was 14.1 kt of lithium contained in minerals and compounds in 2003. Exports from the US increased slightly compared with 2004. Due to strong demand for lithium compounds in 2005, both lithium carbonate plants in Chile were operating at or near capacity.

  12. Low-cycle fatigue behavior of HT-9 alloy in a flowing-lithium environment

    SciTech Connect

    Chopra, O.K.; Smith, D.L.

    1983-06-01

    Low-cycle fatigue data have been obtained on normalized/tempered or lithium-preexposed HT-9 alloy at 755 K in flowing lithium of controlled purity. The results show that the fatigue life of this material decreases with an increase in nitrogen content in lithium. A reduction in strain rate also decreases the fatigue life in high-nitrogen lithium. However, in the range from approx. 4 x 10/sup -4/ to 4 x 10/sup -2/ s/sup -1/, the strain rate has no effect on fatigue life in lithium containing <200 wppM nitrogen. The fatigue life of the HT-9 alloy in low-nitrogen lithium is significantly greater than the fatigue life of Fe-9Cr-1Mo steel or Type 403 martensitic steel in air. Furthermore, a 4.0-Ms preexposure to low-nitrogen lithium has no influence on fatigue life. The reduction in fatigue life in high-nitrogen lithium is attributed to internal corrosive attack of the material. The specimens tested in high-nitrogen lithium show internal corrosion along grain and martensitic lathe boundaries and intergranular fracture. This behavior is not observed in specimens tested in low-nitrogen lithium. Results for a constant-load corrosion test in flowing lithium are also presented.

  13. 2D dry granular free-surface flow over complex topography with obstacles. Part I: experimental study using a consumer-grade RGB-D sensor

    NASA Astrophysics Data System (ADS)

    Caviedes-Voullième, Daniel; Juez, Carmelo; Murillo, Javier; García-Navarro, Pilar

    2014-12-01

    Avalanches, debris flows and other types of gravity-driven granular flows are a common hazard in mountainous regions. These regions often have human settlements in the lower parts of valleys, with human structures dangerously exposed to the destructive effects of these geophysical flows. Therefore a scientific effort has been made to understand, model and simulate geophysical granular flows. In order for computer models and simulations to be of predictive value they need to be validated under controlled, yet nature-like conditions. This work presents an experimental study of granular flow over a simplified mountain slope and valley topography. The experimental facility has a rough bed with very high slope at the upstream end and adverse slope on the downstream end, following a parabolic profile. Obstacles are present in the lower regions. Transient measurements of the moving granular surfaces were taken with a consumer-grade RGB-D sensor, providing transient 2D elevation fields around the obstacles. Three experimental configurations were tested, with semispheres of different diameters and a square dike obstacle. The experimental results are very consistent and repeatable. The quantitative, transient and two-dimensional data for all three experiments constitute excellent benchmarking tests for computational models, such as the one presented in a companion paper.

  14. Transient shear flow of model lithium lubricating greases

    NASA Astrophysics Data System (ADS)

    Delgado, M. A.; Franco, J. M.; Valencia, C.; Kuhn, E.; Gallegos, C.

    2009-03-01

    This paper deals with the analysis of the transient shear flow behavior of lithium lubricating greases differing in soap concentration and base oil viscosity. The shear-induced evolution of grease microstructure has been studied by means of stress-growth experiments. With this aim, different lubricating grease formulations were manufactured by modifying the concentration of lithium 12-hydroxystearate and the viscosity of the base oil, according to a RSM statistical design. Moreover, atomic force microscopy (AFM) observations were carried out. The transient stress response can be successfully described by the generalized Leider-Bird model based on two exponential terms. Different rheological parameters, related to both the elastic response and the structural breakdown of greases, have been analysed. In this sense, it has been found that the elastic properties of lithium lubricating greases were highly influenced by soap concentration and oil viscosity. The stress overshoot, τ max , depends linearly on both variables in the whole shear rate range studied, although the effect of base oil viscosity on this parameter is opposite at low and high shear rates. Special attention has been given to the first part of the stress-growth curve. In this sense, it can be deduced that the “yielding” energy density not only depends on grease composition, but also on shear rate. Moreover, an interesting asymptotic tendency has been found for both the “yielding” energy density and the stress overshoot by increasing shear rate. The asymptotic values of these parameters have been correlated to the friction coefficient obtained in a ball-disc tribometer.

  15. Lithium

    USGS Publications Warehouse

    Ober, J.

    1998-01-01

    The lithium industry can be divided into two sectors: ore concentrate producers and chemical producers. Ore concentrate producers mine lithium minerals. They beneficiate the ores to produce material for use in ceramics and glass manufacturing.

  16. 46 CFR 28.540 - Free surface.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Free surface. 28.540 Section 28.540 Shipping COAST GUARD... Stability § 28.540 Free surface. (a) When doing the stability calculations required by this subpart, the... calculating the following— (1) For each type of consumable liquid, the maximum free surface effect of a...

  17. 46 CFR 28.540 - Free surface.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Free surface. 28.540 Section 28.540 Shipping COAST GUARD... Stability § 28.540 Free surface. (a) When doing the stability calculations required by this subpart, the... calculating the following— (1) For each type of consumable liquid, the maximum free surface effect of a...

  18. 46 CFR 28.540 - Free surface.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Free surface. 28.540 Section 28.540 Shipping COAST GUARD... Stability § 28.540 Free surface. (a) When doing the stability calculations required by this subpart, the... calculating the following— (1) For each type of consumable liquid, the maximum free surface effect of a...

  19. 46 CFR 28.540 - Free surface.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Free surface. 28.540 Section 28.540 Shipping COAST GUARD... Stability § 28.540 Free surface. (a) When doing the stability calculations required by this subpart, the... calculating the following— (1) For each type of consumable liquid, the maximum free surface effect of a...

  20. [Lithium].

    PubMed

    Sparsa, A; Bonnetblanc, J-M

    2004-03-01

    The mode of action of the cation lithium is not well known. It is at present used as a topical drug in dermatology. Lithium inhibits many enzymes: Na/K ATPase, adenylcyclase, enzymes of the prostaglandines E1 synthesis, inositol-1-phosphatase. It is active on neutrophils et T lymphocytes, explaining in part its anti-inflammatory activity. It has a dose-dependent action on levures. It has possibly a direct inhibitory activity on DNA synthesis of herpes viruses. Lithium has a good local safety. Percutaneous penetration is weak and plasma concentrations are very much lower than that observed after oral intake. Lithium has been studied in seborrhoeic dermatitis. Its efficacy was primarily observed in psychotic patients. An assay with oral lithium did not confirmed the first observations. Topical lithium was found more efficient. Topical lithium succinate associated with zinc sulfate and lithium gluconate had a greater efficacy than placebo. Comparison with topical ketoconazole showed a non inferiority of lithium gluconate. Oral lithium also showed a reduction of symptoms' duration of herpes simplex. Cutaneous side-effects of oral lithium are frequent and numerous. Some of them may be explained by a lithium pharmacological cell activity (such as psoriasis). Teratogenicity is observed in mice and rats. Drug interactions are not expected after topical application. Irritants side effects are mainly observed after topical application; they are moderate and transitory. Lithium gluconate treatment of seborrhoeic dermatitis is a bid application during at least 8 weeks. It may be used in renal insufficiency. It is not recommended in the first trimester of pregnancy.

  1. Grid Turbulence Interaction with a Free Surface

    NASA Astrophysics Data System (ADS)

    Huang, Haitao

    1997-11-01

    3-D Flow Diagnostics for Bubbly Two-Phase Flows DARIUS MODARES, DANA DABIRI, STEVE HAASE and KEN CAHDWICK, GALCIT - There is a need for a better understanding of bubble dynamics and in particular the complex phenomenon of bubble interactions with turbulent shear flows. Specifically, we are interested in further examination of the generation of bubbles through cavitation and/or free surface breakage near solid boundaries, their interactions with the rotating surfaces of ship propellers and bubble interaction with the turbulent wake of surface ships. A non-intrusive diagnostic instrumentation based on the Defocusing DPIV (DDPIV) technique suitable for both laboratory and field applications was developed in order to image and track bubbly two-phase flows in a 3-D volume. The defocusing technique uses a single camera. A three aperture pattern is used to obtain a triangular image pattern for each bubble. The position and the size of each triangle is directly related to the bubble size and its 3-D location within the volume of interrogation. We will discuss the details of the technique and quantify the spatial and temporal dynamic range and resolutions. Data related to the 3-D velocity fields of a two-phase vortical flow, bubble size distribution, bubble number density and void fractions will be presented. Sponsored by the Office of Naval Research (N00014-97-1-0303).

  2. Particle accumulation on periodic orbits by repeated free surface collisions

    NASA Astrophysics Data System (ADS)

    Hofmann, Ernst; Kuhlmann, Hendrik C.

    2011-07-01

    The motion of small particles suspended in cylindrical thermocapillary liquid bridges is investigated numerically in order to explain the experimentally observed particle accumulation structures (PAS) in steady two- and time-dependent three-dimensional flows. Particles moving in this flow are modeled as perfect tracers in the bulk, which can undergo collisions with the free surface. By way of free-surface collisions the particles are transferred among different streamlines which represents the particle trajectories in the bulk. The inter-streamline transfer-process near the free surface together with the passive transport through the bulk is used to construct an iterative map that can describe the accumulation process as an attraction to a stable fixed point which represents PAS. The flow topology of the underlying azimuthally traveling hydrothermal wave turns out to be of key importance for the existence of PAS. In a frame of reference exactly rotating with the hydrothermal wave the three-dimensional flow is steady and exhibits co-existing regular and chaotic streamlines. We find that particles are attracted to accumulation structures if a closed regular streamline exists in the rotating frame of reference which closely approaches the free surface locally. Depending on the closed streamline and the particle radius PAS can arise as a specific trajectory which winds about the closed regular streamline or as the surface of a particular stream tube containing the closed streamline.

  3. Numerical evaluation of gas core length in free surface vortices

    NASA Astrophysics Data System (ADS)

    Cristofano, L.; Nobili, M.; Caruso, G.

    2014-11-01

    The formation and evolution of free surface vortices represent an important topic in many hydraulic intakes, since strong whirlpools introduce swirl flow at the intake, and could cause entrainment of floating matters and gas. In particular, gas entrainment phenomena are an important safety issue for Sodium cooled Fast Reactors, because the introduction of gas bubbles within the core causes dangerous reactivity fluctuation. In this paper, a numerical evaluation of the gas core length in free surface vortices is presented, according to two different approaches. In the first one, a prediction method, developed by the Japanese researcher Sakai and his team, has been applied. This method is based on the Burgers vortex model, and it is able to estimate the gas core length of a free surface vortex starting from two parameters calculated with single-phase CFD simulations. The two parameters are the circulation and the downward velocity gradient. The other approach consists in performing a two-phase CFD simulation of a free surface vortex, in order to numerically reproduce the gas- liquid interface deformation. Mapped convergent mesh is used to reduce numerical error and a VOF (Volume Of Fluid) method was selected to track the gas-liquid interface. Two different turbulence models have been tested and analyzed. Experimental measurements of free surface vortices gas core length have been executed, using optical methods, and numerical results have been compared with experimental measurements. The computational domain and the boundary conditions of the CFD simulations were set consistently with the experimental test conditions.

  4. Lithium

    MedlinePlus

    ... depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). Lithium is in a class of medications called antimanic agents. It works by decreasing abnormal activity in the brain.

  5. 46 CFR 28.540 - Free surface.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... calculating the following— (1) For each type of consumable liquid, the maximum free surface effect of a tank... for service tanks; and (2) The free surface effect of each partially filled tank and hold containing a liquid that is not a consumable or containing fish or a fish product that can shift as the vessel...

  6. Bombardment of thin lithium films with energetic plasma flows

    NASA Astrophysics Data System (ADS)

    Gray, Travis Kelly

    The Divertor Erosion and Vapor Shielding Experiment (DEVEX) has been constructed in the Center for Plasma-Material Interactions at the University of Illinois at Urbana-Champaign. It consists of a conical theta-pinch connected to a 60 kV, 36 muF capacitor bank which is switched with a rise time of 3.5 mus. This results in a peak current of 300 kA for a 30 kV charge on the capacitor bank. The resulting plasma is created and compressed under the theta-pinch coil and then expelled axially towards a target chamber due to the conical taper of the theta-coil. The plasma that reaches the target chamber is dense, 1021 m-3 and cool, 10--20 eV. For the purposes of this study, a thin stainless steel target, sputter coated with a lithium magnetron is the target/material of interest. Both computational [A. Hassanein, Fus. Eng. Des. 60: 527546 (2002)] and experimental [M.L. Apicella, et al., J. Nuc. Mater. 386--388:821823 (2009)] studies have shown that lithium, under fusion relevant plasma bombardment, maintains a much lower surface temperature than other plasma facing materials such as tungsten or carbon. This is believed clue to the strong evaporation and/or sputtering of lithium under these conditions. Subsequently a vapor cloud is formed in front of the plasma-facing surface. The lithium vapor interacts with the incident plasma stream absorbing a fraction of the incident plasma energy via the lithium-plasma interactions. Here, we present experimental verification of substantially reduced target surface temperature with the use of thin lithium films on surface of the target as compared to a bare target. Furthermore, optical measurements are made to determine the density and temperature of the lithium vapor cloud as it expands away from the target surface. A collisional-radiative model for both neutrals and singly ionized lithium is used to model the lithium vapor and is found to correlate well with the optical measurements. The vapor cloud electron temperature is found to

  7. Solid-Liquid Lithium Divertor Experiment: SLiDE

    NASA Astrophysics Data System (ADS)

    Jaworski, Michael; Ruzic, David

    2006-10-01

    Liquid lithium has been proposed as a material for the first wall and divertor/limiter of a fusion device. One objection raised against the use of liquid lithium is the high vapor pressure at modest temperature increases. Recent experiments on the CDX-U device show however, that lithium absorbs a surface heat flux of greater than 40 MW/m^2 with negligible evaporation. Observation of a focused electron beam hitting solid lithium in the CDX-U lithium tray saw melting of a large section of the tray. Macroscopic liquid flows were observed which redistributed the incident power. Surface tension effects caused by temperature gradients have been proposed as a mechanism for this convection. These flows were insensitive to MHD effects in fields up to 600G [1]. This paper presents a design of an experiment which will diagnose the flows induced by an intense heat flux onto a lithium pool and measure the maximum heat flux lithium can absorb in an incident magnetic field. A number of diagnostics are considered and evaluated with the goal of being minimally invasive to the induced flows. These results are the first step in the creation of an experimental facility to study the heat transfer capabilities of free-surface liquid lithium at the University of Illinois. [1] Majeski, et al., Final results from the CDX-U lithium program, Presentation at APS-DPP05, Denver, Colorado. 2005.

  8. Crawling beneath the free surface: Water snail locomotion

    NASA Astrophysics Data System (ADS)

    Lee, Sungyon; Bush, John W. M.; Hosoi, A. E.; Lauga, Eric

    2008-08-01

    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being generated by the undulation of the snail foot that is separated from the free surface by a thin layer of mucus. Here, a lubrication model is used to describe the mucus flow in the limit of small-amplitude interfacial deformations. By assuming the shape of the snail foot to be a traveling sine wave and the mucus to be Newtonian, an evolution equation for the interface shape is obtained and the resulting propulsive force on the snail is calculated. This propulsive force is found to be nonzero for moderate values of the capillary number but vanishes in the limits of high and low capillary number. Physically, this force arises because the snail's foot deforms the free surface, thereby generating curvature pressures and lubrication flows inside the mucus layer that couple to the topography of the foot.

  9. Sulphur-impregnated flow cathode to enable high-energy-density lithium flow batteries

    NASA Astrophysics Data System (ADS)

    Chen, Hongning; Zou, Qingli; Liang, Zhuojian; Liu, Hao; Li, Quan; Lu, Yi-Chun

    2015-01-01

    Redox flow batteries are promising technologies for large-scale electricity storage, but have been suffering from low energy density and low volumetric capacity. Here we report a flow cathode that exploits highly concentrated sulphur-impregnated carbon composite, to achieve a catholyte volumetric capacity 294 Ah l-1 with long cycle life (>100 cycles), high columbic efficiency (>90%, 100 cycles) and high energy efficiency (>80%, 100 cycles). The demonstrated catholyte volumetric capacity is five times higher than the all-vanadium flow batteries (60 Ah l-1) and 3-6 times higher than the demonstrated lithium-polysulphide approaches (50-117 Ah l-1). Pseudo-in situ impedance and microscopy characterizations reveal superior electrochemical and morphological reversibility of the sulphur redox reactions. Our approach of exploiting sulphur-impregnated carbon composite in the flow cathode creates effective interfaces between the insulating sulphur and conductive carbon-percolating network and offers a promising direction to develop high-energy-density flow batteries.

  10. Glassy Dynamics Altered by a Free Surface

    NASA Astrophysics Data System (ADS)

    Tsui, Ophelia

    Studies of polymer dynamics in thin films showed that a highly mobile region exists at the free surface of most if not all polymers. In this talk, I shall review some of these observations, with highlights given to the recent findings that chain flexibility and connectivity may on occasions be necessary for the free surface to exercise its influence. Afterward, I shall ponder on how the influence of the free surface may penetrate as far as several polymer radii of gyration into the inner region, as found both in experiments and simulations. Near the glass transition temperature, our MD simulations showed that the dynamics consist mainly of string-like particle hopping motions, as found by others. Importantly, as the temperature decreases, the hopping motions become increasingly repetitive and back-and-forth, contributing no structural relaxations. We propose that structural relaxations are then brought about by pair-interactions between strings. Near the free surface, however, similar repetitive hopping motions are only observed sufficiently far removed from the free surface. We propose that the free surface induces a penetrating surface mobile region by breaking the memory in the particle dynamics. A possible mechanism based on string interactions will be discussed. We are grateful to the support of NSF through Project DMR-1310536 and Hong Kong GRF Grant 15301014.

  11. A finite difference model for free surface gravity drainage

    SciTech Connect

    Couri, F.R.; Ramey, H.J. Jr.

    1993-09-01

    The unconfined gravity flow of liquid with a free surface into a well is a classical well test problem which has not been well understood by either hydrologists or petroleum engineers. Paradigms have led many authors to treat an incompressible flow as compressible flow to justify the delayed yield behavior of a time-drawdown test. A finite-difference model has been developed to simulate the free surface gravity flow of an unconfined single phase, infinitely large reservoir into a well. The model was verified with experimental results in sandbox models in the literature and with classical methods applied to observation wells in the Groundwater literature. The simulator response was also compared with analytical Theis (1935) and Ramey et al. (1989) approaches for wellbore pressure at late producing times. The seepage face in the sandface and the delayed yield behavior were reproduced by the model considering a small liquid compressibility and incompressible porous medium. The potential buildup (recovery) simulated by the model evidenced a different- phenomenon from the drawdown, contrary to statements found in the Groundwater literature. Graphs of buildup potential vs time, buildup seepage face length vs time, and free surface head and sand bottom head radial profiles evidenced that the liquid refills the desaturating cone as a flat moving surface. The late time pseudo radial behavior was only approached after exaggerated long times.

  12. Heat transfer to a thin liquid film with a free surface

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    The numerically computed flow field and heat transfer coefficient are presented for the free surface flow of a thin liquid film in the presence or absence of a gravitational body force. The results of an approximate analysis using the Pohlhausen integral method is also discussed. The flow systems studied here include both plane and radial film flows in the presence or absence of a gravitational body force. The heating conditions include isothermal and uniformly heated surfaces. The transport conditions considered at the free surface are an adiabatic condition and an evaporative free surface maintained at its saturation temperature. The height of the free surface, flow field and heat transfer coefficient, were found to be strongly affected by the gravitational body force. They were also found to depend on the Reynolds number and Froude number of the incoming fluid. In the presence of gravity, a hydraulic jump was found to occur under some flow conditions.

  13. Reversible chemical delithiation/lithiation of LiFePO4: towards a redox flow lithium-ion battery.

    PubMed

    Huang, Qizhao; Li, Hong; Grätzel, Michael; Wang, Qing

    2013-02-14

    Reversible chemical delithiation/lithiation of LiFePO(4) was successfully demonstrated using ferrocene derivatives, based on which a novel energy storage system--the redox flow lithium-ion battery (RFLB), was devised by integrating the operation flexibility of a redox flow battery and high energy density of a lithium-ion battery. Distinct from the recent semi-solid lithium rechargeable flow battery, the energy storage materials of RFLB stored in separate energy tanks remain stationary upon operation, giving us a fresh perspective on building large-scale energy storage systems with higher energy density and improved safety.

  14. Can a dike "feel" a free surface?

    NASA Astrophysics Data System (ADS)

    Pansino, S.; Taisne, B.

    2015-12-01

    This study uses analogue experiments to examine the various factors that could influence the dynamic or arrest of a dike prior to an eruption. Dike propagation has been well-studied from the perspective of analogue experiments and it has been shown how various competing forces interact (buoyancy, viscosity, elastic properties, fracture toughness,…). It has been observed that dikes experience acceleration as they approach a free surface, which theoretically is due to increasing stress intensity as distance to the free surface decreases. Other unrelated studies analysed the constant-volume propagation of low-surface-energy liquids (e.g. hydrophilic liquids) in a semi-infinite medium and found the propagation rate to decelerate, as liquid gradually transferred from the head region to the tail and buoyancy abated. In contrast, high-surface-energy fluids transfer negligible quantities of their volume into the tail region, essentially maintain their volume, and experience no such deceleration. This study focuses on the aforementioned factors influencing dike propagation, acceleration due to a free surface and deceleration due to head volume loss, to determine what their combined effect is on magma eruptability. As previous studies used hydrophobic liquids to investigate free-surface effects, and as magma is expected to have a low surface energy with the crust (they are both silicate), hydrophilic liquids (e.g. glucose syrup) are used in this study. Each experiment is arranged to have a free surface condition occupying half of the apparatus, and a no-slip condition occupying the other half, which allows for side-by-side comparison. The results are analysed to determine the minimum volume needed for a dike to erupt; failure to erupt implies that the dike would instead come to arrest in the crust.

  15. A flowing liquid lithium limiter for the Experimental Advanced Superconducting Tokamak.

    PubMed

    Ren, J; Zuo, G Z; Hu, J S; Sun, Z; Yang, Q X; Li, J G; Zakharov, L E; Xie, H; Chen, Z X

    2015-02-01

    A program involving the extensive and systematic use of lithium (Li) as a "first," or plasma-facing, surface in Tokamak fusion research devices located at Institute of Plasma Physics, Chinese Academy of Sciences, was started in 2009. Many remarkable results have been obtained by the application of Li coatings in Experimental Advanced Superconducting Tokamak (EAST) and liquid Li limiters in the HT-7 Tokamak-both located at the institute. In furtherance of the lithium program, a flowing liquid lithium (FLiLi) limiter system has been designed and manufactured for EAST. The design of the FLiLi limiter is based on the concept of a thin flowing film which was previously tested in HT-7. Exploiting the capabilities of the existing material and plasma evaluation system on EAST, the limiter will be pre-wetted with Li and mechanically translated to the edge of EAST during plasma discharges. The limiter will employ a novel electro-magnetic pump which is designed to drive liquid Li flow from a collector at the bottom of limiter into a distributor at its top, and thus supply a continuously flowing liquid Li film to the wetted plasma-facing surface. This paper focuses on the major design elements of the FLiLi limiter. In addition, a simulation of incoming heat flux has shown that the distribution of heat flux on the limiter surface is acceptable for a future test of power extraction on EAST. PMID:25725839

  16. A flowing liquid lithium limiter for the Experimental Advanced Superconducting Tokamak

    SciTech Connect

    Ren, J.; Zuo, G. Z.; Hu, J. S.; Sun, Z.; Yang, Q. X.; Li, J. G.; Xie, H.; Chen, Z. X.; Zakharov, L. E.

    2015-02-15

    A program involving the extensive and systematic use of lithium (Li) as a “first,” or plasma-facing, surface in Tokamak fusion research devices located at Institute of Plasma Physics, Chinese Academy of Sciences, was started in 2009. Many remarkable results have been obtained by the application of Li coatings in Experimental Advanced Superconducting Tokamak (EAST) and liquid Li limiters in the HT-7 Tokamak—both located at the institute. In furtherance of the lithium program, a flowing liquid lithium (FLiLi) limiter system has been designed and manufactured for EAST. The design of the FLiLi limiter is based on the concept of a thin flowing film which was previously tested in HT-7. Exploiting the capabilities of the existing material and plasma evaluation system on EAST, the limiter will be pre-wetted with Li and mechanically translated to the edge of EAST during plasma discharges. The limiter will employ a novel electro-magnetic pump which is designed to drive liquid Li flow from a collector at the bottom of limiter into a distributor at its top, and thus supply a continuously flowing liquid Li film to the wetted plasma-facing surface. This paper focuses on the major design elements of the FLiLi limiter. In addition, a simulation of incoming heat flux has shown that the distribution of heat flux on the limiter surface is acceptable for a future test of power extraction on EAST.

  17. A flowing liquid lithium limiter for the Experimental Advanced Superconducting Tokamak.

    PubMed

    Ren, J; Zuo, G Z; Hu, J S; Sun, Z; Yang, Q X; Li, J G; Zakharov, L E; Xie, H; Chen, Z X

    2015-02-01

    A program involving the extensive and systematic use of lithium (Li) as a "first," or plasma-facing, surface in Tokamak fusion research devices located at Institute of Plasma Physics, Chinese Academy of Sciences, was started in 2009. Many remarkable results have been obtained by the application of Li coatings in Experimental Advanced Superconducting Tokamak (EAST) and liquid Li limiters in the HT-7 Tokamak-both located at the institute. In furtherance of the lithium program, a flowing liquid lithium (FLiLi) limiter system has been designed and manufactured for EAST. The design of the FLiLi limiter is based on the concept of a thin flowing film which was previously tested in HT-7. Exploiting the capabilities of the existing material and plasma evaluation system on EAST, the limiter will be pre-wetted with Li and mechanically translated to the edge of EAST during plasma discharges. The limiter will employ a novel electro-magnetic pump which is designed to drive liquid Li flow from a collector at the bottom of limiter into a distributor at its top, and thus supply a continuously flowing liquid Li film to the wetted plasma-facing surface. This paper focuses on the major design elements of the FLiLi limiter. In addition, a simulation of incoming heat flux has shown that the distribution of heat flux on the limiter surface is acceptable for a future test of power extraction on EAST.

  18. First results of the use of a continuously flowing lithium limiter in high performance discharges in the EAST device

    NASA Astrophysics Data System (ADS)

    Hu, J. S.; Zuo, G. Z.; Ren, J.; Yang, Q. X.; Chen, Z. X.; Xu, H.; Zakharov, L. E.; Maingi, R.; Gentile, C.; Meng, X. C.; Sun, Z.; Xu, W.; Chen, Y.; Fan, D.; Yan, N.; Duan, Y. M.; Yang, Z. D.; Zhao, H. L.; Song, Y. T.; Zhang, X. D.; Wan, B. N.; Li, J. G.; EAST Team

    2016-04-01

    As an alternative choice of solid plasma facing components (PFCs), flowing liquid lithium can serve as a limiter or divertor PFC and offers a self-healing surface with acceptable heat removal and good impurity control. Such a system could improve plasma performance, and therefore be attractive for future fusion devices. Recently, a continuously flowing liquid lithium (FLiLi) limiter has been successfully designed and tested in the EAST superconducting tokamak. A circulating lithium layer with a thickness of  <0.1 mm and a flow rate ~2 cm3 s-1 was achieved. A novel in-vessel electro-magnetic pump, working with the toroidal magnetic field of the EAST device, was reliable to control the lithium flow speed. The flowing liquid limiter was found to be fully compatible with various plasma scenarios, including high confinement mode plasmas heated by lower hybrid waves or by neutral beam injection. It was also found that the controllable lithium emission from the limiter was beneficial for the reduction of recycling and impurities, for the reduction of divertor heat flux, and in certain cases, for the improvement of plasma stored energy, which bodes well application for the use of flowing liquid lithium PFCs in future fusion devices.

  19. A Liquid Metal Flume for Free Surface Magnetohydrodynamic Experiments

    SciTech Connect

    Nornberg, M.D.; Ji, H.; Peterson, J.L.; Rhoads, J.R.

    2008-08-27

    We present an experiment designed to study magnetohydrodynamic effects in free-surface channel flow. The wide aspect ratio channel (the width to height ratio is about 15) is completely enclosed in an inert atmosphere to prevent oxidization of the liquid metal. A custom-designed pump reduces entrainment of oxygen, which was found to be a problem with standard centrifugal and gear pumps. Laser Doppler Velocimetry experiments characterize velocity profiles of the flow. Various flow constraints mitigate secondary circulation and end effects on the flow. Measurements of the wave propagation characteristics in the liquid metal demonstrate the surfactant effect of surface oxides and the damping of fluctuations by a cross-channel magnetic field.

  20. A carbon-free lithium-ion solid dispersion redox couple with low viscosity for redox flow batteries

    NASA Astrophysics Data System (ADS)

    Qi, Zhaoxiang; Koenig, Gary M.

    2016-08-01

    A new type of non-aqueous redox couple without carbon additives for flow batteries is proposed and the target anolyte chemistry is demonstrated. The so-called "Solid Dispersion Redox Couple" incorporates solid electroactive materials dispersed in organic lithium-ion battery electrolyte as its flowing suspension. In this work, a unique and systematic characterization approach has been used to study the flow battery redox couple in half cell demonstrations relative to a lithium electrode. An electrolyte laden with Li4Ti5O12 (LTO) has been characterized in multiple specially designed lithium half cell configurations. The flow battery redox couple described in this report has relatively low viscosity, especially in comparison to other flow batteries with solid active materials. The lack of carbon additive allows characterization of the electrochemical properties of the electroactive material in flow without the complication of conductive additives and unambiguous observation of the electrorheological coupling in these dispersed particle systems.

  1. Free-surface microfluidics for detection of airborne explosives

    NASA Astrophysics Data System (ADS)

    Meinhart, Carl; Piorek, Brian; Banerjee, Sanjoy; Lee, Seung Joon; Moskovits, Martin

    2008-11-01

    A novel microfluidic, remote-sensing, chemical detection platform has been developed for real-time sensing of airborne agents. The key enabling technology is a newly developed concept termed Free-Surface Fluidics (FSF), where one or more fluidic surfaces of a microchannel flow are confined by surface tension and exposed to the surrounding atmosphere. The result is a unique open channel flow environment that is driven by pressure through surface tension, and not subject to body forces, such as gravity. Evaporation and flow rates are controlled by microchannel geometry, surface chemistry and precisely-controlled temperature profiles. The free-surface fluidic architecture is combined with Surface-Enhanced Raman Spectroscopy (SERS) to allow for real-time profiling of atmospheric species and detection of airborne agents. The aggregation of SERS nanoparticles is controlled using microfluidics, to obtain dimer nanoparticle clusters at known streamwise positions in the microchannel. These dimers form SERS hot-spots, which amplify the Raman signal by 8 -- 10 orders of magnitude. Results indicate that explosive agents such as DNT, TNT, RDX, TATP and picric acid in the surrounding atmosphere can be readily detected by the SERS system. Due to the amplification of the SERS system, explosive molecules with concentrations of parts per trillion can be detected, even in the presence of interferent molecules having six orders of magnitude higher concentration.

  2. Free surface deformation and heat transfer by thermocapillary convection

    NASA Astrophysics Data System (ADS)

    Fuhrmann, Eckart; Dreyer, Michael; Basting, Steffen; Bänsch, Eberhard

    2016-04-01

    Knowing the location of the free liquid/gas surface and the heat transfer from the wall towards the fluid is of paramount importance in the design and the optimization of cryogenic upper stage tanks for launchers with ballistic phases, where residual accelerations are smaller by up to four orders of magnitude compared to the gravity acceleration on earth. This changes the driving forces drastically: free surfaces become capillary dominated and natural or free convection is replaced by thermocapillary convection if a non-condensable gas is present. In this paper we report on a sounding rocket experiment that provided data of a liquid free surface with a nonisothermal boundary condition, i.e. a preheated test cell was filled with a cold but storable liquid in low gravity. The corresponding thermocapillary convection (driven by the temperature dependence of the surface tension) created a velocity field directed away from the hot wall towards the colder liquid and then in turn back at the bottom towards the wall. A deformation of the free surface resulting in an apparent contact angle rather different from the microscopic one could be observed. The thermocapillary flow convected the heat from the wall to the liquid and increased the heat transfer compared to pure conduction significantly. The paper presents results of the apparent contact angle as a function of the dimensionless numbers (Weber-Marangoni and Reynolds-Marangoni number) as well as heat transfer data in the form of a Nusselt number. Experimental results are complemented by corresponding numerical simulations with the commercial software Flow3D and the inhouse code Navier.

  3. High-energy density nonaqueous all redox flow lithium battery enabled with a polymeric membrane.

    PubMed

    Jia, Chuankun; Pan, Feng; Zhu, Yun Guang; Huang, Qizhao; Lu, Li; Wang, Qing

    2015-11-01

    Redox flow batteries (RFBs) are considered one of the most promising large-scale energy storage technologies. However, conventional RFBs suffer from low energy density due to the low solubility of the active materials in electrolyte. On the basis of the redox targeting reactions of battery materials, the redox flow lithium battery (RFLB) demonstrated in this report presents a disruptive approach to drastically enhancing the energy density of flow batteries. With LiFePO4 and TiO2 as the cathodic and anodic Li storage materials, respectively, the tank energy density of RFLB could reach ~500 watt-hours per liter (50% porosity), which is 10 times higher than that of a vanadium redox flow battery. The cell exhibits good electrochemical performance under a prolonged cycling test. Our prototype RFLB full cell paves the way toward the development of a new generation of flow batteries for large-scale energy storage. PMID:26702440

  4. High–energy density nonaqueous all redox flow lithium battery enabled with a polymeric membrane

    PubMed Central

    Jia, Chuankun; Pan, Feng; Zhu, Yun Guang; Huang, Qizhao; Lu, Li; Wang, Qing

    2015-01-01

    Redox flow batteries (RFBs) are considered one of the most promising large-scale energy storage technologies. However, conventional RFBs suffer from low energy density due to the low solubility of the active materials in electrolyte. On the basis of the redox targeting reactions of battery materials, the redox flow lithium battery (RFLB) demonstrated in this report presents a disruptive approach to drastically enhancing the energy density of flow batteries. With LiFePO4 and TiO2 as the cathodic and anodic Li storage materials, respectively, the tank energy density of RFLB could reach ~500 watt-hours per liter (50% porosity), which is 10 times higher than that of a vanadium redox flow battery. The cell exhibits good electrochemical performance under a prolonged cycling test. Our prototype RFLB full cell paves the way toward the development of a new generation of flow batteries for large-scale energy storage. PMID:26702440

  5. High-energy density nonaqueous all redox flow lithium battery enabled with a polymeric membrane.

    PubMed

    Jia, Chuankun; Pan, Feng; Zhu, Yun Guang; Huang, Qizhao; Lu, Li; Wang, Qing

    2015-11-01

    Redox flow batteries (RFBs) are considered one of the most promising large-scale energy storage technologies. However, conventional RFBs suffer from low energy density due to the low solubility of the active materials in electrolyte. On the basis of the redox targeting reactions of battery materials, the redox flow lithium battery (RFLB) demonstrated in this report presents a disruptive approach to drastically enhancing the energy density of flow batteries. With LiFePO4 and TiO2 as the cathodic and anodic Li storage materials, respectively, the tank energy density of RFLB could reach ~500 watt-hours per liter (50% porosity), which is 10 times higher than that of a vanadium redox flow battery. The cell exhibits good electrochemical performance under a prolonged cycling test. Our prototype RFLB full cell paves the way toward the development of a new generation of flow batteries for large-scale energy storage.

  6. Thermocapillary convection in two immiscible liquid layers with free surface

    NASA Technical Reports Server (NTRS)

    Doi, Takao; Koster, Jean N.

    1993-01-01

    Thermocapillary convection is studied in two immiscible liquid layers with one free surface, one liquid/liquid interface, and differential heating applied parallel to the interfaces. An analytical solution is introduced for infinite horizontal layers. The defining parameter for the flow pattern is lambda, the ratio of the temperature coefficient of the interfacial tension to that of the surface tension. Four different flow patterns exist under zero gravity conditions. 'Halt' conditions which halt the fluid motion in the lower encapsulated liquid layer have been found. A numerical experiment is carried out to study effects of vertical end walls on the double layer convection in a 2D cavity. The halt condition obtained from the analytical study is found to be valid in the limit of small Reynolds numbers. The flow in the encapsulated liquid layer can be suppressed substantially.

  7. Material and Energy Flows in the Production of Cathode and Anode Materials for Lithium Ion Batteries

    SciTech Connect

    Dunn, Jennifer B.; James, Christine; Gaines, Linda; Gallagher, Kevin; Dai, Qiang; Kelly, Jarod C.

    2015-09-01

    The Greenhouse gases, Regulated Emissions and Energy use in Transportation (GREET) model has been expanded to include four new cathode materials that can be used in the analysis of battery-powered vehicles: lithium nickel cobalt manganese oxide (LiNi0.4Co0.2Mn0.4O2 [NMC]), lithium iron phosphate (LiFePO4 [LFP]), lithium cobalt oxide (LiCoO2 [LCO]), and an advanced lithium cathode (0.5Li2MnO3∙0.5LiNi0.44Co0.25Mn0.31O2 [LMR-NMC]). In GREET, these cathode materials are incorporated into batteries with graphite anodes. In the case of the LMR-NMC cathode, the anode is either graphite or a graphite-silicon blend. Lithium metal is also an emerging anode material. This report documents the material and energy flows of producing each of these cathode and anode materials from raw material extraction through the preparation stage. For some cathode materials, we considered solid state and hydrothermal preparation methods. Further, we used Argonne National Laboratory’s Battery Performance and Cost (BatPaC) model to determine battery composition (e.g., masses of cathode, anode, electrolyte, housing materials) when different cathode materials were used in the battery. Our analysis concluded that cobalt- and nickel-containing compounds are the most energy intensive to produce.

  8. Free surface electrospinning of fibers containing microparticles.

    PubMed

    Brettmann, Blair K; Tsang, Shirley; Forward, Keith M; Rutledge, Gregory C; Myerson, Allan S; Trout, Bernhardt L

    2012-06-26

    Many materials have been fabricated using electrospinning, including pharmaceutical formulations, superhydrophobic surfaces, catalysis supports, filters, and tissue engineering scaffolds. Often these materials can benefit from microparticles included within the electrospun fibers. In this work, we evaluate a high-throughput free surface electrospinning technique to prepare fibers containing microparticles. We investigate the spinnability of polyvinylpyrrolidone (PVP) solutions containing suspended polystyrene (PS) beads of 1, 3, 5, and 10 μm diameter in order to better understand free surface electrospinning of particle suspensions. PS bead suspensions with both 55 kDa PVP and 1.3 MDa PVP were spinnable at 1:10, 1:5, and 1:2 PS:PVP mass loadings for all particle sizes studied. The final average fiber diameters ranged from 0.47 to 1.2 μm and were independent of the particle size and particle loading, indicating that the fiber diameter can be smaller than the particles entrained and can furthermore be adjusted based on solution properties and electrospinning parameters, as is the case for electrospinning of solutions without particles.

  9. Numerical simulation of sloshing with large deforming free surface by MPS-LES method

    NASA Astrophysics Data System (ADS)

    Pan, Xu-jie; Zhang, Huai-xin; Sun, Xue-yao

    2012-12-01

    Moving particle semi-implicit (MPS) method is a fully Lagrangian particle method which can easily solve problems with violent free surface. Although it has demonstrated its advantage in ocean engineering applications, it still has some defects to be improved. In this paper, MPS method is extended to the large eddy simulation (LES) by coupling with a sub-particle-scale (SPS) turbulence model. The SPS turbulence model turns into the Reynolds stress terms in the filtered momentum equation, and the Smagorinsky model is introduced to describe the Reynolds stress terms. Although MPS method has the advantage in the simulation of the free surface flow, a lot of non-free surface particles are treated as free surface particles in the original MPS model. In this paper, we use a new free surface tracing method and the key point is "neighbor particle". In this new method, the zone around each particle is divided into eight parts, and the particle will be treated as a free surface particle as long as there are no "neighbor particles" in any two parts of the zone. As the number density parameter judging method has a high efficiency for the free surface particles tracing, we combine it with the neighbor detected method. First, we select out the particles which may be mistreated with high probabilities by using the number density parameter judging method. And then we deal with these particles with the neighbor detected method. By doing this, the new mixed free surface tracing method can reduce the mistreatment problem efficiently. The serious pressure fluctuation is an obvious defect in MPS method, and therefore an area-time average technique is used in this paper to remove the pressure fluctuation with a quite good result. With these improvements, the modified MPS-LES method is applied to simulate liquid sloshing problems with large deforming free surface. Results show that the modified MPS-LES method can simulate the large deforming free surface easily. It can not only capture

  10. Development of liquid-lithium film jet-flow for the target of (7)Li(p,n)(7)Be reactions for BNCT.

    PubMed

    Kobayashi, Tooru; Miura, Kuniaki; Hayashizaki, Noriyosu; Aritomi, Masanori

    2014-06-01

    A feasibility study on liquid lithium target in the form of a flowing film was performed to evaluate its potential use as a neutron generation target of (7)Li(p,n)(7)Be reaction in BNCT. The target is a windowless-type flowing film on a concave wall. Its configuration was adapted for a proton beam which is 30mm in diameter and with energy and current of up to 3MeV and 20mA, respectively. The flowing film of liquid lithium was 0.6mm in thickness, 50mm in width and 50mm in length. The shapes of the nozzle and concave back wall, which create a stable flowing film jet, were decided based on water experiments. A lithium hydrodynamic experiment was performed to observe the stability of liquid lithium flow behavior. The flowing film of liquid lithium was found to be feasible at temperatures below the liquid lithium boiling saturation of 342°C at the surface pressure of 1×10(-3)Pa. Using a proto-type liquid lithium-circulating loop for BNCT, the stability of the film flow was confirmed for velocities up to 30m/s at 220°C and 250°C in vacuum at a pressure lower than 10(-3) Pa. It is expected that for practical use, a flowing liquid lithium target of a windowless type can solve the problem of radiation damage and target cooling.

  11. On the Way Toward Understanding Solution Chemistry of Lithium Polysulfides for High Energy Li-S Redox Flow Batteries

    SciTech Connect

    Pan, Huilin; Wei, Xiaoliang; Henderson, Wesley A.; Shao, Yuyan; Chen, Junzheng; Bhattacharya, Priyanka; Xiao, Jie; Liu, Jun

    2015-04-27

    Lithium sulfur (Li-S) redox flow battery (RFB) is a promising candidate for high energy large-scale energy storage application due to good solubility of long-chain polysulfide species and low cost of sulfur. In this report, recent progress and new concepts for Li-S redox flow batteries are discussed with an emphasis on the fundamental understanding and control of lithium polysulfide chemistry to enable the development of liquid phase Li-S redox flow prototype cells. These differ significantly from conventional static Li-S batteries targeting for vehicle electrification. A high solubility of the different lithium polysulfides generated at different depths of discharge and states of charge is required for a flow battery in order to take full advantage of the multiple electron transitions between elemental sulfur and Li2S. A new DMSO-based electrolyte is proposed for Li-S redox flow batteries, which not only enables the high solubility of lithium polysulfide species, especially for the short-chain species, but also results in excellent cycling with a high Coulombic efficiency. The challenges and opportunities for the Li-S redox flow concept have also been discussed in depth.

  12. Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow

    SciTech Connect

    Gu, W.B.; Jungst, Rudolph G.; Nagasubramanian, Ganesan; Wang, C.Y.; Weidner, John.

    1999-06-11

    A two-dimensional model is developed to simulate discharge of a lithium/thionyl chloride primary battery. The model accounts for not only transport of species and charge, but also the electrode porosity variations and the electrolyte flow induced by the volume reduction caused by electrochemical reactions. Numerical simulations are performed using a finite volume method of computational fluid dynamics. The predicted discharge curves for various temperatures are compared to the experimental data with excellent agreement. Moreover, the simulation results. in conjunction with computer visualization and animation techniques, confirm that cell utilization in the temperature and current range of interest is limited by pore plugging or clogging of the front side of the cathode as a result of LiCl precipitation. The detailed two-dimensional flow simulation also shows that the electrolyte is replenished from the cell header predominantly through the separator into the front of the cathode during most parts of the discharge, especially for higher cell temperatures.

  13. 46 CFR 42.20-10 - Free surface.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Free surface. 42.20-10 Section 42.20-10 Shipping COAST... Freeboards § 42.20-10 Free surface. When doing the calculations required in §§ 42.20-6(a), 42.20-7(a) and 42.20-8(a), the effect of free surface of the following liquids must be included: (a) For each type...

  14. 46 CFR 42.20-10 - Free surface.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Free surface. 42.20-10 Section 42.20-10 Shipping COAST... Freeboards § 42.20-10 Free surface. When doing the calculations required in §§ 42.20-6(a), 42.20-7(a) and 42.20-8(a), the effect of free surface of the following liquids must be included: (a) For each type...

  15. 46 CFR 42.20-10 - Free surface.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Free surface. 42.20-10 Section 42.20-10 Shipping COAST... Freeboards § 42.20-10 Free surface. When doing the calculations required in §§ 42.20-6(a), 42.20-7(a) and 42.20-8(a), the effect of free surface of the following liquids must be included: (a) For each type...

  16. 46 CFR 42.20-10 - Free surface.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Free surface. 42.20-10 Section 42.20-10 Shipping COAST... Freeboards § 42.20-10 Free surface. When doing the calculations required in §§ 42.20-6(a), 42.20-7(a) and 42.20-8(a), the effect of free surface of the following liquids must be included: (a) For each type...

  17. 46 CFR 42.20-10 - Free surface.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Free surface. 42.20-10 Section 42.20-10 Shipping COAST... Freeboards § 42.20-10 Free surface. When doing the calculations required in §§ 42.20-6(a), 42.20-7(a) and 42.20-8(a), the effect of free surface of the following liquids must be included: (a) For each type...

  18. Aqueous Lithium-Iodine Solar Flow Battery for the Simultaneous Conversion and Storage of Solar Energy.

    PubMed

    Yu, Mingzhe; McCulloch, William D; Beauchamp, Damian R; Huang, Zhongjie; Ren, Xiaodi; Wu, Yiying

    2015-07-01

    Integrating both photoelectric-conversion and energy-storage functions into one device allows for the more efficient solar energy usage. Here we demonstrate the concept of an aqueous lithium-iodine (Li-I) solar flow battery (SFB) by incorporation of a built-in dye-sensitized TiO2 photoelectrode in a Li-I redox flow battery via linkage of an I3(-)/I(-) based catholyte, for the simultaneous conversion and storage of solar energy. During the photoassisted charging process, I(-) ions are photoelectrochemically oxidized to I3(-), harvesting solar energy and storing it as chemical energy. The Li-I SFB can be charged at a voltage of 2.90 V under 1 sun AM 1.5 illumination, which is lower than its discharging voltage of 3.30 V. The charging voltage reduction translates to energy savings of close to 20% compared to conventional Li-I batteries. This concept also serves as a guiding design that can be extended to other metal-redox flow battery systems. PMID:26102317

  19. Aqueous Lithium-Iodine Solar Flow Battery for the Simultaneous Conversion and Storage of Solar Energy.

    PubMed

    Yu, Mingzhe; McCulloch, William D; Beauchamp, Damian R; Huang, Zhongjie; Ren, Xiaodi; Wu, Yiying

    2015-07-01

    Integrating both photoelectric-conversion and energy-storage functions into one device allows for the more efficient solar energy usage. Here we demonstrate the concept of an aqueous lithium-iodine (Li-I) solar flow battery (SFB) by incorporation of a built-in dye-sensitized TiO2 photoelectrode in a Li-I redox flow battery via linkage of an I3(-)/I(-) based catholyte, for the simultaneous conversion and storage of solar energy. During the photoassisted charging process, I(-) ions are photoelectrochemically oxidized to I3(-), harvesting solar energy and storing it as chemical energy. The Li-I SFB can be charged at a voltage of 2.90 V under 1 sun AM 1.5 illumination, which is lower than its discharging voltage of 3.30 V. The charging voltage reduction translates to energy savings of close to 20% compared to conventional Li-I batteries. This concept also serves as a guiding design that can be extended to other metal-redox flow battery systems.

  20. Numerical Simulation of Floating Bodies in Extreme Free Surface Waves

    NASA Astrophysics Data System (ADS)

    Hu, Zheng Zheng; Causon, Derek; Mingham, Clive; Qiang, Ling

    2010-05-01

    and efficient. Firstly, extreme design wave conditions are generated in an empty NWT and compared with physical experiments as a precursor to calculations to investigate the survivability of the Bobber device operating in a challenging wave climate. Secondly, we consider a bench-mark test case involving in a first order regular wave maker acting on a fixed cylinder and Pelamis. Finally, a floating Bobber has been simulated under extreme wave conditions. These results will be reported at the meeting. Causon D.M., Ingram D.M., Mingham C.G., Yang G. Pearson R.V. (2000). Calculation of shallow water flows using a Cartesian cut cell approach. Advances in Water resources, 23: 545-562. Causon D.M., Ingram D.M., Mingham C.G. (2000). A Cartesian cut cell method for shallow water flows with moving boundaries. Advances in Water resources, 24: 899-911. Dalzell J.F. 1999 A note on finite depth second-order wave-wave interactions. Appl. Ocean Res. 21, 105-111. Ning D.Z., Zang J., Liu S.X. Eatock Taylor R. Teng B. & Taylor P.H. 2009 Free surface and wave kinematics for nonlinear focused wave groups. J. Ocean Engineering. Accepted. Hu Z.Z., Causon D.M., Mingham C.M. and Qian L.(2009). Numerical wave tank study of a wave energy converter in heave. Proceedlings 19th ISOPE conference, Osaka, Japan Qian L., Causon D.M. & Mingham C.G., Ingram D.M. 2006 A free-surface capturing method for two fluid flows with moving bodies. Proc. Roy. Soc. London, Vol. A 462 21-42.

  1. Spectral simulation of thermocapillary convection with a deformable free surface using boundary-fitted coordinates

    NASA Astrophysics Data System (ADS)

    Ahmed, Ikramuddin

    A Chebyshev-spectral collocation scheme has been developed to simulate thermocapillary convection processes in a differentially heated cavity with and without buoyancy effects. The time-dependent Navier- Stokes equations in primitive variables were solved with a semi-implicit scheme using the influence matrix technique. The deformable free surface was incorporated by means of a boundary-fitted coordinate (BFC) system. The BFC grid was generated by solving a system of elliptic equations. An iterative scheme based on finite difference methods was found to be sufficient for calculating a smooth distribution of grid-points for relatively low degrees of deformation of the free surface. The metrics of transformation, however, were calculated spectrally in order to achieve a high order of accuracy in the a posteriori mapping of the physical grid to the computational grid. The overall scheme was found to be efficient, economical, and capable of resolving the complex hydrodynamic and thermal structures in thermocapillarity driven flows with deformable free surfaces. The scheme was also modified to study problems with very high Marangoni numbers and non-deformable free surfaces, and later extended to three dimensions with periodic boundary conditions in order to explore the transitions to fully three dimensional phenomena that are anticipated in industrially relevant flow configurations.

  2. Low-Reynolds-number rising of a bubble near a free surface at vanishing Bond number

    NASA Astrophysics Data System (ADS)

    Guémas, Marine; Sellier, Antoine; Pigeonneau, Franck

    2016-06-01

    This work considers a nearly spherical bubble and a nearly flat free surface interacting under buoyancy at vanishing Bond number Bo. For each perturbed surface, the deviation from the unperturbed shape is asymptotically obtained at leading order on Bo. The task appeals to the normal traction exerted on the unperturbed surface by the Stokes flow due to a spherical bubble translating toward a flat free surface. The free surface problem is then found to be well-posed and to admit a solution in closed form when gravity is still present in the linear differential equation governing the perturbed profile through a term proportional to Bo. In contrast, the bubble problem amazingly turns out to be over-determined. It however becomes well-posed if the requirement of horizontal tangent planes at the perturbed bubble north and south poles is discarded or if the term proportional to Bo is omitted. Both previous approaches turn out to predict for a small Bond number, quite close solutions except in the very vicinity of the bubble poles. The numerical solution of the proposed asymptotic analysis shows in the overlapping range Bo = O ( 0.1 ) and for both the bubble and the free surface perturbed shapes, a good agreement with a quite different boundary element approach developed in Pigeonneau and Sellier ["Low-Reynolds-number gravity-driven migration and deformation of bubbles near a free surface," Phys. Fluids 23, 092102 (2011)]. It also provides approximated bubble and free surface shapes whose sensitivity to the bubble location is examined.

  3. Kidney function and lithium concentrations of rats given an injection of lithium orotate or lithium carbonate.

    PubMed

    Smith, D F; Schou, M

    1979-03-01

    A recent study by Kling et al (1978) noted the finding of higher lithium concentrations in serum and brain of rats after an intraperitoneal injection (2 mmol lithium kg-1) of lithium orotate as a slurry than of lithium carbonate in solution. The authors suggested that lithium orotate might offer advantages in the treatment of patients. We repeated the experiments of Kling et al but in addition examined the kidney function of the rats. Glomerular filtration rate and urine flow were markedly lower in rats given lithium orotate than in rats given lithium carbonate, sodium chloride or a sham injection. The renal lithium clearance was significantly lower, the kidney weight and the lithium concentrations in serum, kidney and heart significantly higher after injection of lithium orotate than after injection of lithium carbonate. The higher lithium concentrations could be accounted for by the lower kidney function. It seems inadvisable to use lithium orotate for the treatment of patients. PMID:34690

  4. Experimental Characterization of Thermo-electric Driven Liquid Lithium Flow in Narrow Trenches for Magnetic Confinement Fusion

    NASA Astrophysics Data System (ADS)

    Xu, Wenyu; Christenson, Michael; Fiflis, Peter; Curreli, Davide; Andruczyk, Daniel; Ruzic, David

    2013-10-01

    The application of liquid metal, especially liquid lithium has become an important topic for plasma facing component (PFC) design. A liquid PFC can effectively eliminate the erosion and thermal stress problems compared to the solid PFC while transferring heat and prolong the lifetime limit of the PFCs. A liquid lithium surface can also suppress the hydrogen isotopes recycling and getter the impurities in fusion reactors. The Lithium/metal infused trench (LiMIT) concept successfully proved that the thermoelectric effect can be utilized to drive liquid lithium flow within horizontally placed metallic open trenches in transverse magnetic field. A limiter based on this concept was tested in HT-7 and gave out positive results. However a broader application of this concept may require the trench be tilted or even placed vertically, for which strong capillary force caused by narrow trenches may be the solution. A new LiMIT design with very narrow trenches have been manufactured and tested in University of Illinois and related results will be presented. Based on this idea new limiters are designed for EAST and LTX and scheduled experiments on both devices will be discussed. This project is supported by DOE/ALPS contract: DEFG02- 99ER54515.

  5. Variational space-time (dis)continuous Galerkin method for nonlinear free surface water waves

    NASA Astrophysics Data System (ADS)

    Gagarina, E.; Ambati, V. R.; van der Vegt, J. J. W.; Bokhove, O.

    2014-10-01

    A new variational finite element method is developed for nonlinear free surface gravity water waves using the potential flow approximation. This method also handles waves generated by a wave maker. Its formulation stems from Miles' variational principle for water waves together with a finite element discretization that is continuous in space and discontinuous in time. One novel feature of this variational finite element approach is that the free surface evolution is variationally dependent on the mesh deformation vis-à-vis the mesh deformation being geometrically dependent on free surface evolution. Another key feature is the use of a variational (dis)continuous Galerkin finite element discretization in time. Moreover, in the absence of a wave maker, it is shown to be equivalent to the second order symplectic Störmer-Verlet time stepping scheme for the free-surface degrees of freedom. These key features add to the stability of the numerical method. Finally, the resulting numerical scheme is verified against nonlinear analytical solutions with long time simulations and validated against experimental measurements of driven wave solutions in a wave basin of the Maritime Research Institute Netherlands.

  6. Effect of Marangoni number on thermocapillary convection and free-surface deformation in liquid bridges

    NASA Astrophysics Data System (ADS)

    Zhang, Yin; Huang, Hu-Lin; Zhou, Xiao-Ming; Zhu, Gui-Ping; Zou, Yong

    2016-04-01

    Floating zone technique is a crucible-free process for growth of high quality single crystals. Unstable thermocapillary convection is a typical phenomenon during the process under microgravity. Therefore, it is very important to investigate the instability of thermocapillary convection in liquid bridges with deformable free-surface under microgravity. In this works, the Volume of Fluid (VOF) method is employed to track the free-surface movement. The results are presented as the behavior of flow structure and temperature distribution of the molten zone. The impact of Marangoni number ( Ma) is also investigated on free-surface deformation as well as the instability of thermocapillary convection. The free-surface exhibits a noticeable axisymmetric (but it is non-centrosymmetric) and elliptical shape along the circumferential direction. This specific surface shape presents a typical narrow `neck-shaped' structure with convex at two ends of the zone and concave at the mid-plane along the axial direction. At both θ = 0° and θ = 90°, the deformation ratio ξ increases rapidly with Ma at first, and then increases slowly. Moreover, the hydrothermal wave number m and the instability of thermocapillary convection increase with Ma.

  7. A chemistry and material perspective on lithium redox flow batteries towards high-density electrical energy storage.

    PubMed

    Zhao, Yu; Ding, Yu; Li, Yutao; Peng, Lele; Byon, Hye Ryung; Goodenough, John B; Yu, Guihua

    2015-11-21

    Electrical energy storage system such as secondary batteries is the principle power source for portable electronics, electric vehicles and stationary energy storage. As an emerging battery technology, Li-redox flow batteries inherit the advantageous features of modular design of conventional redox flow batteries and high voltage and energy efficiency of Li-ion batteries, showing great promise as efficient electrical energy storage system in transportation, commercial, and residential applications. The chemistry of lithium redox flow batteries with aqueous or non-aqueous electrolyte enables widened electrochemical potential window thus may provide much greater energy density and efficiency than conventional redox flow batteries based on proton chemistry. This Review summarizes the design rationale, fundamentals and characterization of Li-redox flow batteries from a chemistry and material perspective, with particular emphasis on the new chemistries and materials. The latest advances and associated challenges/opportunities are comprehensively discussed. PMID:26265165

  8. A chemistry and material perspective on lithium redox flow batteries towards high-density electrical energy storage.

    PubMed

    Zhao, Yu; Ding, Yu; Li, Yutao; Peng, Lele; Byon, Hye Ryung; Goodenough, John B; Yu, Guihua

    2015-11-21

    Electrical energy storage system such as secondary batteries is the principle power source for portable electronics, electric vehicles and stationary energy storage. As an emerging battery technology, Li-redox flow batteries inherit the advantageous features of modular design of conventional redox flow batteries and high voltage and energy efficiency of Li-ion batteries, showing great promise as efficient electrical energy storage system in transportation, commercial, and residential applications. The chemistry of lithium redox flow batteries with aqueous or non-aqueous electrolyte enables widened electrochemical potential window thus may provide much greater energy density and efficiency than conventional redox flow batteries based on proton chemistry. This Review summarizes the design rationale, fundamentals and characterization of Li-redox flow batteries from a chemistry and material perspective, with particular emphasis on the new chemistries and materials. The latest advances and associated challenges/opportunities are comprehensively discussed.

  9. Measuring flow and pressure of lithium coolant under developmental testing of a high-temperature cooling system of a space nuclear power plant

    NASA Astrophysics Data System (ADS)

    Sobolev, V. Ya.; Sinyavsky, V. V.

    2014-12-01

    Sub-megawatt space NPP use lithium as a coolant and niobium alloy as a structural material. In order to refine the lithium-niobium technology of the material and design engineering, lithium-niobium loops were worked out in RSC Energia, and they were tested at a working temperature of lithium equal to 1070-1300 K. In order to measure the lithium flow and pressure, special gauges were developed, which made possible the calibration and checkout of the loops without their dismantling. The paper describes the architecture of the electromagnetic flowmeter and the electromagnetic vibrating-wire pressure transducer (gauge) for lithium coolant in the nuclear power plant cooling systems. The operating principles of these meters are presented. Flowmeters have been developed for channel diameters ranging from 10 to 100 mm, which are capable of measuring lithium flows in the range of 0.1 to 30 L/s with the error of 3% for design calibration and 1% for volume graduation. The temperature error of the pressure transducers does not exceed 0.4% per 100 K; the nonlinearity and hysteresis of the calibration curve do not exceed 0.3 and 0.4%, respectively. The transducer applications are illustrated by the examples of results obtained from tests on the NPP module mockup and heat pipes of a radiation cooler.

  10. Front instability and energy of the free surface

    NASA Astrophysics Data System (ADS)

    Beltrame, Philippe

    2014-05-01

    In recent years, there has been a proliferation of research devoted to the formation of preferential flow paths occurring without macroscopic heterogeneity of the porous media. DiCarlo (2013) points out the connection between "overshoot" and the front instability. Extension of the standard Richards equation is required to capture this phenomenon. In most of the improvements, interfacial phenomena as the triple line at the front are considered. For instance, velocity dependent contact angle (Wang et al., 2013) or contact angle hysteresis (Rätz and Schweizer, 2012) allow to simulate successfully the instability. Another approach proposed by Cueto-Felgueroso and Juanes (2009) introduces a macroscopic surface tension related to the existence of the water/air interface. As previously, the simulation of an advancing front displays physical looking fingering displacements. The goal of this contribution is to better understand the role of the different surface energies in the emergence of the front instability. We propose a model involving both the macroscopic surface tension and the soil wettability. This latter allows to define a contact angle and possibly hysteresis using heterogeneous wettability (Beltrame et al., 2011). Therefore, we employ the phase field approach developed by Felgueroso and Juanes, 2009 to which we add a free energy term corresponding to the wettability: a disjoining or conjoining pressure resulting from effective molecular interactions between the substrate and the free surface (DeGennes, 1985). The difference with the classical suction pressure is the hydrophobic behavior for ultra-thin film (small water saturation). Such a water repellency was recently estimated in the soil (Diamantopoulos et al. 2013). Stability analysis of an advancing front in an uniform porous media shows that macroscopic surface tension and wettability may independently produce the instability growth. In contrast, for a front stopping when reaching the layers interface of

  11. Bubble Bursting at a Free Surface in a Closed Domain

    NASA Astrophysics Data System (ADS)

    Liu, Nian-Nian; Zhang, Shuai; Wang, Shi-Ping

    2016-06-01

    When a charge explodes underwater near a free surface, a bubble would be generated and the surface pushed up very high. Experiments have shown that the motion of the spike lags a lot behind the bubble motion. Many studies only focus on the nonlinear interaction between the bubble and free surface while the water waves afterward is mainly studied based on the linear theory. The nonlinear motion of the water wave after the bubble pulsation is seldom studied. In this study, we concerns the interaction between underwater explosion generated bubble and a free surface and its bursting at a free surface in a closed domain. Suppose that the fluid outside the bubble is incompressible, non-viscous and irrotational and the velocity potential satisfies the Laplace equation. Boundary integral method is used to solve the Laplace equation for the velocity potential. The bubble content is described by an adiabatic law. The whole process of the bubble motion and subsequently the water wave propagation will be simulated in this paper. Particular attention will be focused on the phenomenon of water wave propagation in a closed domain.

  12. Passive manipulation of free-surface instability by deformable solid bilayers.

    PubMed

    Sahu, Shivam; Shankar, V

    2016-07-01

    This study deals with the elastohydrodynamic coupling that occurs in the flow of a liquid layer down an inclined plane lined with a deformable solid bilayer and its consequences on the stability of the free surface of the liquid layer. The fluid is Newtonian and incompressible, while the linear elastic constitutive relation has been considered for the deformable solid bilayer, and the densities of the fluid and the two solids are kept equal. A temporal linear stability analysis is carried out for this coupled solid-fluid system. A long-wave asymptotic analysis is employed to obtain an analytical expression for the complex wavespeed in the low wave-number regime, and a numerical shooting method is used to solve the coupled set of governing differential equations in order to obtain the stability criterion for arbitrary values of the wave number. In a previous work on plane Couette flow past an elastic bilayer, Neelmegam et al. [Phys. Rev. E 90, 043004 (2014)PLEEE81539-375510.1103/PhysRevE.90.043004] showed that the instability of the flow can be significantly influenced by the nature of the solid layer, which is adjacent to the liquid layer. In stark contrast, for free-surface flow past a bilayer, our long-wave asymptotic analysis demonstrates that the stability of the free-surface mode is insensitive to the nature of the solid adjacent to the liquid layer. Instead, it is the effective shear modulus of the bilayer G_{eff} (given by H/G_{eff}=H_{1}/G_{1}+H_{2}/G_{2}, where H=H_{1}+H_{2} is the total thickness of the solid bilayer, H_{1} and H_{2} are the thicknesses of the two solid layers, and G_{1} and G_{2} are the shear moduli of the two solid layers) that determines the stability of the free surface in the long-wave limit. We show that for a given Reynolds number, the free-surface instability is stabilized when G_{eff} decreases below a critical value. At finite wave numbers, our numerical solution indicates that additional instabilities at the free surface and

  13. Passive manipulation of free-surface instability by deformable solid bilayers

    NASA Astrophysics Data System (ADS)

    Sahu, Shivam; Shankar, V.

    2016-07-01

    This study deals with the elastohydrodynamic coupling that occurs in the flow of a liquid layer down an inclined plane lined with a deformable solid bilayer and its consequences on the stability of the free surface of the liquid layer. The fluid is Newtonian and incompressible, while the linear elastic constitutive relation has been considered for the deformable solid bilayer, and the densities of the fluid and the two solids are kept equal. A temporal linear stability analysis is carried out for this coupled solid-fluid system. A long-wave asymptotic analysis is employed to obtain an analytical expression for the complex wavespeed in the low wave-number regime, and a numerical shooting method is used to solve the coupled set of governing differential equations in order to obtain the stability criterion for arbitrary values of the wave number. In a previous work on plane Couette flow past an elastic bilayer, Neelmegam et al. [Phys. Rev. E 90, 043004 (2014), 10.1103/PhysRevE.90.043004] showed that the instability of the flow can be significantly influenced by the nature of the solid layer, which is adjacent to the liquid layer. In stark contrast, for free-surface flow past a bilayer, our long-wave asymptotic analysis demonstrates that the stability of the free-surface mode is insensitive to the nature of the solid adjacent to the liquid layer. Instead, it is the effective shear modulus of the bilayer Geff (given by H /Geff=H1/G1+H2/G2 , where H =H1+H2 is the total thickness of the solid bilayer, H1 and H2 are the thicknesses of the two solid layers, and G1 and G2 are the shear moduli of the two solid layers) that determines the stability of the free surface in the long-wave limit. We show that for a given Reynolds number, the free-surface instability is stabilized when Geff decreases below a critical value. At finite wave numbers, our numerical solution indicates that additional instabilities at the free surface and the liquid-solid interface can be induced by wall

  14. Passive manipulation of free-surface instability by deformable solid bilayers.

    PubMed

    Sahu, Shivam; Shankar, V

    2016-07-01

    This study deals with the elastohydrodynamic coupling that occurs in the flow of a liquid layer down an inclined plane lined with a deformable solid bilayer and its consequences on the stability of the free surface of the liquid layer. The fluid is Newtonian and incompressible, while the linear elastic constitutive relation has been considered for the deformable solid bilayer, and the densities of the fluid and the two solids are kept equal. A temporal linear stability analysis is carried out for this coupled solid-fluid system. A long-wave asymptotic analysis is employed to obtain an analytical expression for the complex wavespeed in the low wave-number regime, and a numerical shooting method is used to solve the coupled set of governing differential equations in order to obtain the stability criterion for arbitrary values of the wave number. In a previous work on plane Couette flow past an elastic bilayer, Neelmegam et al. [Phys. Rev. E 90, 043004 (2014)PLEEE81539-375510.1103/PhysRevE.90.043004] showed that the instability of the flow can be significantly influenced by the nature of the solid layer, which is adjacent to the liquid layer. In stark contrast, for free-surface flow past a bilayer, our long-wave asymptotic analysis demonstrates that the stability of the free-surface mode is insensitive to the nature of the solid adjacent to the liquid layer. Instead, it is the effective shear modulus of the bilayer G_{eff} (given by H/G_{eff}=H_{1}/G_{1}+H_{2}/G_{2}, where H=H_{1}+H_{2} is the total thickness of the solid bilayer, H_{1} and H_{2} are the thicknesses of the two solid layers, and G_{1} and G_{2} are the shear moduli of the two solid layers) that determines the stability of the free surface in the long-wave limit. We show that for a given Reynolds number, the free-surface instability is stabilized when G_{eff} decreases below a critical value. At finite wave numbers, our numerical solution indicates that additional instabilities at the free surface and

  15. Experimental investigation of a free-surface turbulent jet with Coanda effect

    NASA Astrophysics Data System (ADS)

    Miozzi, M.; Lalli, F.; Romano, G. P.

    2010-07-01

    The deviation of a jet from the straight direction due to the presence of a lateral wall is investigated from the experimental point of view. This flow condition is known as Coanda jet (from the Romanian aerodynamicist Henry Marie Coanda who discovered and applied it at the beginning of XXth century) or offset jet. The objective of the work is to detail the underlying mechanisms of such a phenomenon aiming to use it as a flow control method at polluted river flows mouth. To do this, a large laboratory free-surface tank with an incoming channel has been set up and velocity field measurements are performed by Optical Flow methods (namely Feature Tracking). Preliminary tests on the well-known free jet configuration without any marine structure ( i.e. lateral wall) are performed to allow comparison with free jet scaling and self-similar solutions. The presence of the free-surface gives rise to centerline velocity decay which is lower than in free unbounded plane or circular jets due to the vertically limited ambient fluid entrainment. In the second part of the paper, the effect of a lateral wall on the jet configuration is examined by placing it at different lateral distances from the jet outlet. The resulting velocity fields clearly show an inclined Coanda jet with details which seems to depend on the lateral wall distance itself. The analysis of self-similarity along the inclined jet direction reveals that for wall distances larger than 5 jet widths this dependence almost disappears.

  16. Mechanism of Bursting Taylor Bubbles at Free Surfaces.

    PubMed

    Rana, Basanta K; Das, Arup K; Das, Prasanta K

    2015-09-15

    Collapse of a Taylor bubble inside a pipe at the free surface of a liquid is studied experimentally using speed imaging camera and illumination and subsequent image analysis. Three different fluids, water, glycerin, and silicone oil, are employed in the experiments. For all conditions studied herein, the bubble punctures at the free surface to form two thin films, i.e., one covering the cross-section of the tube near the free surface and one along the tube wall in the vertical direction. Surface tension acts to collapse the first film, which widens the punctured hole in the outward radial direction, thereby feeding the liquid in the vertical film. After the shrinking of the radial film, gravity causes the collapse of the vertical film, which generates a tiny jet of liquid at the end of collapse. Experiments with different fluids show a drastic change in shape and thickness of the vertical film that leads to higher drainage time. Analysis of time scale for the drainage of the horizontal film exhibits a favorable match with experiments. Finally, evolution of the vertical film is analyzed using a simple hydrodynamic model to estimate the order magnitude of time taken to collapse, which compares well with processed image data from experiments. PMID:26301827

  17. Vortical and nonlinear effects in the roll motion of a 2-D body in the free surface investigated by SPH

    NASA Astrophysics Data System (ADS)

    Olmez, O.; Ozbulut, M.; Yildiz, M.; Goren, O.

    2016-06-01

    The present study investigates the vortical and nonlinear effects in the roll motion of a 2-D body with square cross-sections by using Smoothed Particle Hydrodynamics (SPH). A 2-D rigid body with square cross-section is taken into account for the benchmark study and subjected to the oscillatory roll motion with a given angular frequency. The governing equations are continuity equation and Euler's equation with artificial viscosity term. Weakly Compressible SPH (WCSPH) scheme is employed for the discretization of the governing equations. Velocities of the fluid particles are updated by means of XSPH+Artificial Particle Displacement (VXSPH+APD) algorithm. In this method only the free surface fluid particles are subjected to VXSPH algorithm while the APD algorithm is employed for the fully populated flow regions. The hybrid usage of numerical treatment keeps free surface particles together by creating an artificial surface tension on the free surface. VXSPH+APD is a proven numerical treatment to provide the most accurate results for this type of free surface flows (Ozbulut et al. 2014). The results of the present study are compared with those of the experimental studies as well as with those of the numerical methods obtained from the current literature.

  18. Material and energy flows in the materials production, assembly, and end-of-life stages of the automotive lithium-ion battery life cycle

    SciTech Connect

    Dunn, J.B.; Gaines, L.; Barnes, M.; Wang, M.; Sullivan, J.

    2012-06-21

    This document contains material and energy flows for lithium-ion batteries with an active cathode material of lithium manganese oxide (LiMn{sub 2}O{sub 4}). These data are incorporated into Argonne National Laboratory's Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model, replacing previous data for lithium-ion batteries that are based on a nickel/cobalt/manganese (Ni/Co/Mn) cathode chemistry. To identify and determine the mass of lithium-ion battery components, we modeled batteries with LiMn{sub 2}O{sub 4} as the cathode material using Argonne's Battery Performance and Cost (BatPaC) model for hybrid electric vehicles, plug-in hybrid electric vehicles, and electric vehicles. As input for GREET, we developed new or updated data for the cathode material and the following materials that are included in its supply chain: soda ash, lime, petroleum-derived ethanol, lithium brine, and lithium carbonate. Also as input to GREET, we calculated new emission factors for equipment (kilns, dryers, and calciners) that were not previously included in the model and developed new material and energy flows for the battery electrolyte, binder, and binder solvent. Finally, we revised the data included in GREET for graphite (the anode active material), battery electronics, and battery assembly. For the first time, we incorporated energy and material flows for battery recycling into GREET, considering four battery recycling processes: pyrometallurgical, hydrometallurgical, intermediate physical, and direct physical. Opportunities for future research include considering alternative battery chemistries and battery packaging. As battery assembly and recycling technologies develop, staying up to date with them will be critical to understanding the energy, materials, and emissions burdens associated with batteries.

  19. Material and Energy Flows in the Materials Production, Assembly, and End-of-Life Stages of the Automotive Lithium-Ion Battery Life Cycle

    SciTech Connect

    Dunn, Jennifer B.; Gaines, Linda; Barnes, Matthew; Sullivan, John L.; Wang, Michael

    2014-01-01

    This document contains material and energy flows for lithium-ion batteries with an active cathode material of lithium manganese oxide (LiMn₂O₄). These data are incorporated into Argonne National Laboratory’s Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model, replacing previous data for lithium-ion batteries that are based on a nickel/cobalt/manganese (Ni/Co/Mn) cathode chemistry. To identify and determine the mass of lithium-ion battery components, we modeled batteries with LiMn₂O₄ as the cathode material using Argonne’s Battery Performance and Cost (BatPaC) model for hybrid electric vehicles, plug-in hybrid electric vehicles, and electric vehicles. As input for GREET, we developed new or updated data for the cathode material and the following materials that are included in its supply chain: soda ash, lime, petroleum-derived ethanol, lithium brine, and lithium carbonate. Also as input to GREET, we calculated new emission factors for equipment (kilns, dryers, and calciners) that were not previously included in the model and developed new material and energy flows for the battery electrolyte, binder, and binder solvent. Finally, we revised the data included in GREET for graphite (the anode active material), battery electronics, and battery assembly. For the first time, we incorporated energy and material flows for battery recycling into GREET, considering four battery recycling processes: pyrometallurgical, hydrometallurgical, intermediate physical, and direct physical. Opportunities for future research include considering alternative battery chemistries and battery packaging. As battery assembly and recycling technologies develop, staying up to date with them will be critical to understanding the energy, materials, and emissions burdens associated with batteries.

  20. Study on Applicability of Numerical Simulation to Evaluation of Gas Entrainment From Free Surface

    SciTech Connect

    Kei Ito; Takaaki Sakai; Hiroyuki Ohshima

    2006-07-01

    An onset condition of gas entrainment (GE) due to free surface vortex has been studied to establish a design of fast breeder reactor with higher coolant velocity than conventional designs, because the GE might cause the reactor operation instability and therefore should be avoided. The onset condition of the GE has been investigated experimentally and theoretically, however, dependency of the vortex type GE on local geometry configuration of each experimental system and local velocity distribution has prevented researchers from formulating the universal onset condition of the vortex type GE. A real scale test is considered as an accurate method to evaluate the occurrence of the vortex type GE, but the real scale test is generally expensive and not useful in the design study of large and complicated FBR systems, because frequent displacement of inner equipments accompanied by the design change is difficult in the real scale test. Numerical simulation seems to be promising method as an alternative to the real scale test. In this research, to evaluate the applicability of the numerical simulation to the design work, numerical simulations were conducted on the basic experimental system of the vortex type GE. This basic experiment consisted of rectangular flow channel and two important equipments for vortex type GE in the channel, i.e. vortex generation and suction equipments. Generated vortex grew rapidly interacting with the suction flow and the grown vortex formed a free surface dent (gas core). When the tip of the gas core or the bubbles detached from the tip of the gas core reached the suction mouth, the gas was entrained to the suction tube. The results of numerical simulation under the experimental conditions were compared to the experiment in terms of velocity distributions and free surface shape. As a result, the numerical simulation showed qualitatively good agreement with experimental data. The numerical simulation results were similar to the experimental

  1. Review of free-surface MHD experiments and modeling.

    SciTech Connect

    Molokov, S.; Reed, C. B.

    2000-06-02

    This review paper was prepared to survey the present status of analytical and experimental work in the area of free surface MHD and thus provide a well informed starting point for further work by the Advanced Limiter-diverter Plasma-facing Systems (ALPS) program. ALPS were initiated to evaluate the potential for improved performance and lifetime for plasma-facing systems. The main goal of the program is to demonstrate the advantages of advanced limiter/diverter systems over conventional systems in terms of power density capability, component lifetime, and power conversion efficiency, while providing for safe operation and minimizing impurity concerns for the plasma. Most of the work to date has been applied to free surface liquids. A multi-disciplinary team from several institutions has been organized to address the key issues associated with these systems. The main performance goals for advanced limiters and diverters are a peak heat flux of >50 MW/m{sup 2}, elimination of a lifetime limit for erosion, and the ability to extract useful heat at high power conversion efficiency ({approximately}40%). The evaluation of various options is being conducted through a combination of laboratory experiments, modeling of key processes, and conceptual design studies.

  2. Mathematical and computational studies of equilibrium capillary free surfaces

    NASA Technical Reports Server (NTRS)

    Albright, N.; Chen, N. F.; Concus, P.; Finn, R.

    1977-01-01

    The results of several independent studies are presented. The general question is considered of whether a wetting liquid always rises higher in a small capillary tube than in a larger one, when both are dipped vertically into an infinite reservoir. An analytical investigation is initiated to determine the qualitative behavior of the family of solutions of the equilibrium capillary free-surface equation that correspond to rotationally symmetric pendent liquid drops and the relationship of these solutions to the singular solution, which corresponds to an infinite spike of liquid extending downward to infinity. The block successive overrelaxation-Newton method and the generalized conjugate gradient method are investigated for solving the capillary equation on a uniform square mesh in a square domain, including the case for which the solution is unbounded at the corners. Capillary surfaces are calculated on the ellipse, on a circle with reentrant notches, and on other irregularly shaped domains using JASON, a general purpose program for solving nonlinear elliptic equations on a nonuniform quadrilaterial mesh. Analytical estimates for the nonexistence of solutions of the equilibrium capillary free-surface equation on the ellipse in zero gravity are evaluated.

  3. Plankton dynamics in thermally-stratified free-surface turbulence

    NASA Astrophysics Data System (ADS)

    Lovecchio, Salvatore; Soldati, Alfredo

    2015-11-01

    Thermal stratification induced by solar heating near the ocean-atmosphere interface influences the transfer fluxes of heat, momentum and chemical species across the interface. Due to thermal stratification, a region of large temperature gradients (thermocline) may form with strong consequences for the marine ecosystem. In particular, the thermocline is believed to prevent phytoplankton from reaching the well-lit surface layer, where they can grow through the process of photosynthesis. In this paper, we use a DNS-based Eulerian-Lagrangian approach to examine the role of stratification on phytoplankton dynamics in thermally-stratified free-surface turbulence. We focus on gyrotactic self-propelled phytoplankton cells, considering different stratification levels (quantified by the Richardson number) and different gyro tactic re-orientation times. We show that the modulation of turbulent fluctuations induced by stable stratification has a strong effect on the orientation and distribution of phytoplankton, possibly leading to trapping of some species within the thermocline. Specifically, we observe the appearance of a depletion layer just below the free-surface as stratification increases, accompanied by a reduction in the vertical stability of phytoplankton cells.

  4. Free surface BCP self-assembly process characterization with CDSEM

    NASA Astrophysics Data System (ADS)

    Levi, Shimon; Weinberg, Yakov; Adan, Ofer; Klinov, Michael; Argoud, Maxime; Claveau, Guillaume; Tiron, Raluca

    2016-03-01

    A simple and common practice to evaluate Block copolymers (BCP) self-assembly performances, is on a free surface wafer. With no guiding pattern the BCP designed to form line space pattern for example, spontaneously rearranges to form a random fingerprint type of a pattern. The nature of the rearrangement is dictated by the physical properties of the BCP moieties, wafer surface treatment and the self-assembly process parameters. Traditional CDSEM metrology algorithms are designed to measure pattern with predefined structure, like linespace or oval via holes. Measurement of pattern with expected geometry can reduce measurement uncertainty. Fingerprint type of structure explored in this dissertation, poses a challenge for CD-SEM measurement uncertainty and offers an opportunity to explore 2D metrology capabilities. To measure this fingerprints we developed a new metrology approach that combines image segmentation and edge detection to measure 2D pattern with arbitrary rearrangement. The segmentation approach enabled to quantify the quality of the BCP material and process, detecting 2D attributes such as: CD and CDU at one axis, and number of intersections, length and number of PS fragments, etched PMMA spaces and donut shapes numbers on the second axis. In this paper we propose a 2D metrology to measure arbitrary BCP pattern on a free surface wafer. We demonstrate experimental results demonstrating precision data, and characterization of PS-b-PMMA BCP, intrinsic period L0 = 38nm (Arkema), processed at different bake time and temperatures.

  5. Oscillatory thermocapillary convection in liquid bridges with highly deformed free surfaces: Experiments and energy-stability analysis

    NASA Astrophysics Data System (ADS)

    Sumner, L. B. S.; Neitzel, G. P.; Fontaine, J.-P.; Dell'Aversana, P.

    2001-01-01

    Laboratory experimentation, numerical simulation, and energy-stability theory are used to examine the effect of interface deformation on the onset of oscillatory thermocapillary convection in half zones. Experiments are performed to map the stability boundaries marking the onset of oscillatory flow, modifying the free-surface deformation by adjusting the volume of liquid in the bridge. The stability results presented here along with those of other researchers [Monti et al., Proceedings of the 43rd Cong. Int. Artro. Fed. (1992); Hu et al., J. Cryst. Growth 142, 379 (1994)] show that free-surface curvature can have a pronounced influence on flow stability. Steady, axisymmetric flow simulations are computed using the commercial code FIDAP to model the conditions of the experiments, and reveal that flow structure near the stability boundary is sensitive to several parameters. Energy theory is applied to these simulations to determine sufficient conditions for stability. Comparisons between the theoretical and experimental results show nonconservative energy limits falling above the experimentally determined stability boundaries for bridges of various liquid volumes. While the trend of the experimental data is predicted for zones of large volume ratio (bulging zones), the same cannot be said for those with small volume ratio (necked-down zones). In addition, energy-stability limits for some undeformed-free-surface cases were determined which are above the linear-stability limits determined by other researchers, in clear contradiction of the roles of the respective theories.

  6. 46 CFR 170.290 - Free surface correction for damage stability calculations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Free surface correction for damage stability...) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Free Surface § 170.290 Free surface correction for damage stability calculations. (a) When doing the damage stability calculations required...

  7. 46 CFR 170.285 - Free surface correction for intact stability calculations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Free surface correction for intact stability...) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Free Surface § 170.285 Free surface correction for intact stability calculations. (a) When doing the intact stability calculations required...

  8. 46 CFR 170.285 - Free surface correction for intact stability calculations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Free surface correction for intact stability...) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Free Surface § 170.285 Free surface correction for intact stability calculations. (a) When doing the intact stability calculations required...

  9. 46 CFR 170.285 - Free surface correction for intact stability calculations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Free surface correction for intact stability...) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Free Surface § 170.285 Free surface correction for intact stability calculations. (a) When doing the intact stability calculations required...

  10. 46 CFR 170.290 - Free surface correction for damage stability calculations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Free surface correction for damage stability...) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Free Surface § 170.290 Free surface correction for damage stability calculations. (a) When doing the damage stability calculations required...

  11. Recent Advances in Applicability of TEMHD Driven Liquid Lithium as a Fusion Relevant PFC

    NASA Astrophysics Data System (ADS)

    Szott, Matthew; Fiflis, Peter; Kalathiparambil, Kishor; Ruzic, David N.

    2015-11-01

    Liquid lithium displays increasing promise as a replacement to solid plasma facing components (PFC) in fusion device applications. Liquid PFCs reduce erosion and thermal stress damage, prolonging device lifetime, while lithium has been shown to decrease edge recycling, reduce impurities, and enhance plasma performance. The Liquid Metal Infused Trench (LiMIT) concept developed at UIUC successfully demonstrates horizontal and vertical thermoelectric magnetohydrodynamic (TEMHD) flow of liquid lithium through metal trenches for use as a PFC. Installed in the HT-7 tokamak and at the Magnum-PSI linear plasma device, the system performed effectively in fusion relevant conditions. In high heat flux tests, trench dry-out was observed, which exposes solid trench material due to higher TEMHD force on the area with the highest heat flux. A 3D free surface fluid model of dry-out and experimental tests conducted to mitigate the detrimental effect are described. The final designs for the upcoming test of LiMIT as a limiter for the EAST tokamak are discussed, along with velocity characteristics of steady-state TEMHD driven flow through the LiMIT system inclined up to 180 degrees from horizontal, which is necessary for broad applicability of a liquid lithium PFC system.

  12. Free surface stability of liquid metal plasma facing components

    NASA Astrophysics Data System (ADS)

    Fiflis, P.; Christenson, M.; Szott, M.; Kalathiparambil, K.; Ruzic, D. N.

    2016-10-01

    An outstanding concern raised over the implementation of liquid metal plasma facing components in fusion reactors is the potential for ejection of liquid metal into the fusion plasma. The influences of Rayleigh-Taylor-like and Kelvin-Helmholtz-like instabilities were experimentally observed and quantified on the thermoelectric-driven liquid-metal plasma-facing structures (TELS) chamber at the University of Illinois at Urbana-Champaign. To probe the stability boundary, plasma currents and velocities were first characterized with a flush probe array. Subsequent observations of lithium ejection under exposure in the TELS chamber exhibited a departure from previous theory based on linear perturbation analysis. The stability boundary is mapped experimentally over the range of plasma impulses of which TELS is capable to deliver, and a new theory based on a modified set of the shallow water equations is presented which accurately predicts the stability of the lithium surface under plasma exposure.

  13. A topological study of gravity free-surface waves generated by bluff bodies using the method of steepest descents

    NASA Astrophysics Data System (ADS)

    Trinh, Philippe H.

    2016-07-01

    The standard analytical approach for studying steady gravity free-surface waves generated by a moving body often relies upon a linearization of the physical geometry, where the body is considered asymptotically small in one or several of its dimensions. In this paper, a methodology that avoids any such geometrical simplification is presented for the case of steady-state flows at low speeds. The approach is made possible through a reduction of the water-wave equations to a complex-valued integral equation that can be studied using the method of steepest descents. The main result is a theory that establishes a correspondence between different bluff-bodied free-surface flow configurations, with the topology of the Riemann surface formed by the steepest descent paths. Then, when a geometrical feature of the body is modified, a corresponding change to the Riemann surface is observed, and the resultant effects to the water waves can be derived. This visual procedure is demonstrated for the case of two-dimensional free-surface flow past a surface-piercing ship and over an angled step in a channel.

  14. The threshold origin of solutocapillary Marangoni convection on a bounded free surface

    NASA Astrophysics Data System (ADS)

    Viviani, Antonio; Denisova, Maria; Kostarev, Konstantin; Zuev, Andrew

    2014-09-01

    The Marangoni convection is the key mechanism responsible for the motion of non-isothermal fluid with a free surface under microgravity conditions. It is generally assumed that the surface of a Newtonian fluid begins to move at any arbitrary small shear stress. However, the experiments show that under actual conditions the capillary fluid flow can be initiated by a certain (threshold) stress. For subthreshold shear stresses generated by the surface forces or volumetric flows, the fluid surface remains immovable. Such a behavior of the surface is caused by the existence of an adsorption layer formed by uncontrolled surface-active impurities contained in the fluid. The composition and amount of impurities absorbed on the surface are dependent on the degree of purification of the fluid and the value of its surface tension. The condition of a threshold initiation of the capillary motion has been determined experimentally for the case of development of the solutal Marangoni convection after placing a droplet of the surfactant liquor on the interface of water, aqueous surfactant solutions of lower concentrations and some organic fluids. A group of monohydric alcohols and carboxylic acids were used as the surfactants. It has been found that the value of the threshold difference in surfactant concentration rapidly increases with a decrease in fluid initial concentration and the characteristic dimension of the free surface. Due to the latter fact the threshold effects are of crucial importance for a variety of problems in microfluidics. It has been found that a threshold origin of a capillary motion is also peculiar to the liquid-liquid interface. The relationships between the threshold Marangoni number and the surface activity of a surfactant have been determined.

  15. Label-free surface plasmon sensing towards cancer diagnostics

    NASA Astrophysics Data System (ADS)

    Sankaranarayanan, Goutham

    The main objective of this thesis is to develop a conventional, home-built SPR bio-sensor to demonstrate bio-sensing applications. This emphasizes the understanding of basic concepts of Surface Plasmon Resonance and various interrogation techniques. Intensity Modulation was opted to perform the label-free SPR bio-sensing experiments due to its cost-efficient and compact setup. Later, label-free surface plasmon sensing was carried out to study and understand the bio-molecular interactions between (1). BSA and Anti BSA molecules and (2). Exosome/Liposome on thin metal (Au) films. Exosomes are cell-derived vesicles present in bodily fluids like blood, saliva, urine, epididymal fluid containing miRNAs, RNA, proteins, etc., at stable quantities during normal health conditions. The exosomes comprise varied constituents based on their cell origin from where they are secreted and is specific to that particular origin. However an exacerbated release is observed during tumor or cancer conditions. This increased level of exosomes present in the sample, can be detected using the SPR bio-sensor demonstrated in this thesis and effective thickness of adsorption on Au surface can be estimated. Also, chemically synthesized liposome particles were studied to determine if they can generate an equivalent sensor response to that of exosomes to consider them as an alternate. Finally a 10ppb Mercury (Hg) sensing was performed as part of Environment Monitoring application and results have been tabulated and compared.

  16. Fabrication of Adhesive Lenses Using Free Surface Shaping

    NASA Astrophysics Data System (ADS)

    Hoheisel, D.; Kelb, C.; Wall, M.; Roth, B.; Rissing, L.

    2013-09-01

    Two approaches for fabricating polymer lenses are presented in this paper. Both are based on filling circular holes with UV curing adhesives. Initially, the viscous adhesive material creates a liquid and spherical free surface due to its own surface tension. This shape is then preserved by curing with UV-hardening light. For the first approach, the holes are generated in a 4 inch Si-wafer by deep reactive ion etching (DRIE) and for the second, a polydimethylsiloxane (PDMS) mould is manufactured. Three types of UV-curing adhesives are investigated (NOA 61, NOA 88 and NEA 121 by Norland Products). Preliminary to the determination of the lens curvature, a contact angle goniometer is used for taking side view images of the lenses. The radius of curvature is then extracted via image processing with the software MATLAB®. Furthermore, the surface roughness of the PDMS mould and the generated lenses is measured with a white light interferometer to characterize the casting process. The resolution power of the generated lenses is evaluated by measurement of their point spread functions (psf) and modulation transfer functions (mtf), respectively.

  17. Glasses crystallize rapidly at free surfaces by growing crystals upward.

    PubMed

    Sun, Ye; Zhu, Lei; Kearns, Kenneth L; Ediger, Mark D; Yu, Lian

    2011-04-12

    The crystallization of glasses and amorphous solids is studied in many fields to understand the stability of amorphous materials, the fabrication of glass ceramics, and the mechanism of biomineralization. Recent studies have found that crystal growth in organic glasses can be orders of magnitude faster at the free surface than in the interior, a phenomenon potentially important for understanding glass crystallization in general. Current explanations differ for surface-enhanced crystal growth, including released tension and enhanced mobility at glass surfaces. We report here a feature of the phenomenon relevant for elucidating its mechanism: Despite their higher densities, surface crystals rise substantially above the glass surface as they grow laterally, without penetrating deep into the bulk. For indomethacin (IMC), an organic glass able to grow surface crystals in two polymorphs (α and γ), the growth front can be hundreds of nanometers above the glass surface. The process of surface crystal growth, meanwhile, is unperturbed by eliminating bulk material deeper than some threshold depth (ca. 300 nm for α IMC and less than 180 nm for γ IMC). As a growth strategy, the upward-lateral growth of surface crystals increases the system's surface energy, but can effectively take advantage of surface mobility and circumvent slow growth in the bulk.

  18. Influence of free surface curvature on the Pearson instability in Marangoni convection

    NASA Astrophysics Data System (ADS)

    Hu, W. R.

    The Peason instability in a liquid layer bounded by a plate solid boundary with higher constant temperature and a plane free surface with lower constant temperatures in the microgravity environment has by extensively studied The free surface in the microgravity environment tends to be curved in general as a spherical shape and the plane configuration of free surface is a special case In the present paper a system of liquid layer bounded by a plat solid boundary with higher constant temperature and a curved free surface with lower non-uniform temperature is studied The temperature gradient on the free surface will induce the thermocapillary convection and the onset of Marangoni convection is coupled with the thermocapillary convection The thermocapillary convection induced by the temperature gradient on the curved free surface and its influence on the Marangoni convection are studied in the present paper

  19. Thermal characteristics of air flow cooling in the lithium ion batteries experimental chamber

    SciTech Connect

    Lukhanin A.; Rohatgi U.; Belyaev, A.; Fedorchenko, D.; Khazhmuradov, M.; Lukhanin, O; Rudychev, I.

    2012-07-08

    A battery pack prototype has been designed and built to evaluate various air cooling concepts for the thermal management of Li-ion batteries. The heat generation from the Li-Ion batteries was simulated with electrical heat generation devices with the same dimensions as the Li-Ion battery (200 mm x 150 mm x 12 mm). Each battery simulator generates up to 15W of heat. There are 20 temperature probes placed uniformly on the surface of the battery simulator, which can measure temperatures in the range from -40 C to +120 C. The prototype for the pack has up to 100 battery simulators and temperature probes are recorder using a PC based DAQ system. We can measure the average surface temperature of the simulator, temperature distribution on each surface and temperature distributions in the pack. The pack which holds the battery simulators is built as a crate, with adjustable gap (varies from 2mm to 5mm) between the simulators for air flow channel studies. The total system flow rate and the inlet flow temperature are controlled during the test. The cooling channel with various heat transfer enhancing devices can be installed between the simulators to investigate the cooling performance. The prototype was designed to configure the number of cooling channels from one to hundred Li-ion battery simulators. The pack is thermally isolated which prevents heat transfer from the pack to the surroundings. The flow device can provide the air flow rate in the gap of up to 5m/s velocity and air temperature in the range from -30 C to +50 C. Test results are compared with computational modeling of the test configurations. The present test set up will be used for future tests for developing and validating new cooling concepts such as surface conditions or heat pipes.

  20. Slow viscous gravity-driven interaction between a bubble and a free surface with unequal surface tensions

    NASA Astrophysics Data System (ADS)

    Guémas, Marine; Sellier, Antoine; Pigeonneau, Franck

    2015-04-01

    The axisymmetric gravity-driven dynamics of a bubble rising toward a free surface is addressed for gas-liquid interfaces having unequal surface tensions. The liquid flow is governed by the Stokes equations which are here solved using a boundary element method in axisymmetric configuration. Within this framework, two dimensionless numbers arise: the Bond number Bo1 based on the surface tension of the bubble interface and the surface tension ratio γ ˆ comparing the free surface and bubble surface tensions. Under a careful and discussed selection of the code key settings (number of boundary elements, initial bubble location, and distance beyond which the free surface is truncated), it has been possible to numerically and accurately track in time the bubble and free surface shapes for several values of ( Bo 1 , γ ˆ ) . The long-time shapes are found to deeply depend upon both Bo1 and γ ˆ and also to compare well with the shapes predicted in Princen and Mason ["Shape of a fluid drop at a fluid-liquid interface. II. Theory for three-phase systems," J. Colloid. Sci. 20, 246-266 (1965)] using a hydrostatic model in which both surfaces are touching. Similarly, the drainage dynamics of the liquid film thickness between the bubble and the free surface depends on ( Bo 1 , γ ˆ ) . The long-time film thickness exponentially decays in time and a so-called thinning rate α for which the numerical behaviors and a simple model reveal two basic behaviors: (i) at small Bond number, α behaves as 1/Bo1 and (ii) at large Bond number, α is nearly constant. In addition, it is found that in the entire range of the quantity χ = ( 1 + γ ˆ ) Bo 1 / ( 2 γ ˆ ) , the thinning rate α is well approximated by the function 1/(18χ) + α∞ with α∞ ≈ 0.158. Such a result also permits one to estimate the typical drainage time versus the initial bubble radius a, the liquid density ρ and viscosity μ, the gravity and the free surface, and bubble surface tensions.

  1. Subduction Initiation from a Stagnant Lid: New Insights from Numerical Models with a Free Surface

    NASA Astrophysics Data System (ADS)

    Crameri, Fabio; Tackley, Paul

    2016-04-01

    Subduction initiation is key in understanding the dynamic evolution of the Earth and its fundamental difference to all other rocky planetary bodies in our solar system. Despite recent progress, the question about how a stiff, mostly stagnant planetary lid can break and become part in the global overturn of the mantle is still unresolved. Here, we present results on subduction initiation obtained by dynamically self-consistent, time-dependent numerical modelling of mantle convection and single-sided subduction (Crameri et al., 2012b) using the finite-difference, multigrid code StagYY (Tackley 2008). We show that the stress distribution and resulting deformation of the lithosphere is strongly controlled by the top boundary formulation: A free surface enables surface topography and plate bending, increases gravitational sliding of the plates and leads to more realistic, lithosphere-scale shear zones. As a consequence, subduction initiation induced by regional mantle flow is significantly favoured by a free surface compared to the commonly-applied, vertically-fixed (i.e., free-slip) surface. In addition, we present global, three-dimensional mantle convection experiments (see e.g. Crameri and Tackley, 2014) that employ basal heating that leads to narrow mantle plumes. Narrow mantle plumes impinging on the base of the plate cause locally weak plate segments and a large topography at the lithosphere-asthenosphere boundary. Both are shown to be key to induce subduction initiation. Finally, our model self-consistently reproduces an episodic lid with a fast global overturn due to the hotter mantle developed below a former stagnant lid. We conclude that once in a stagnant-lid mode, a planet (like Venus) thus preferentially evolves by temporally discrete, global overturn events rather than by a continuous recycling of lid. REFERENCES Crameri, F, Tackley, P.J, Meilick, I, Gerya, T.V, Kaus, B.J.P (2012) A free plate surface and weak oceanic crust produce single-sided subduction

  2. A new free-surface stabilization algorithm for geodynamical modelling: Theory and numerical tests

    NASA Astrophysics Data System (ADS)

    Andrés-Martínez, Miguel; Morgan, Jason P.; Pérez-Gussinyé, Marta; Rüpke, Lars

    2015-09-01

    The surface of the solid Earth is effectively stress free in its subaerial portions, and hydrostatic beneath the oceans. Unfortunately, this type of boundary condition is difficult to treat computationally, and for computational convenience, numerical models have often used simpler approximations that do not involve a normal stress-loaded, shear-stress free top surface that is free to move. Viscous flow models with a computational free surface typically confront stability problems when the time step is bigger than the viscous relaxation time. The small time step required for stability (< 2 Kyr) makes this type of model computationally intensive, so there remains a need to develop strategies that mitigate the stability problem by making larger (at least ∼10 Kyr) time steps stable and accurate. Here we present a new free-surface stabilization algorithm for finite element codes which solves the stability problem by adding to the Stokes formulation an intrinsic penalization term equivalent to a portion of the future load at the surface nodes. Our algorithm is straightforward to implement and can be used with both Eulerian or Lagrangian grids. It includes α and β parameters to respectively control both the vertical and the horizontal slope-dependent penalization terms, and uses Uzawa-like iterations to solve the resulting system at a cost comparable to a non-stress free surface formulation. Four tests were carried out in order to study the accuracy and the stability of the algorithm: (1) a decaying first-order sinusoidal topography test, (2) a decaying high-order sinusoidal topography test, (3) a Rayleigh-Taylor instability test, and (4) a steep-slope test. For these tests, we investigate which α and β parameters give the best results in terms of both accuracy and stability. We also compare the accuracy and the stability of our algorithm with a similar implicit approach recently developed by Kaus et al. (2010). We find that our algorithm is slightly more accurate

  3. Predictions of nearshore hydrodynamics based on free-surface lattice Boltzmann approximations

    NASA Astrophysics Data System (ADS)

    Frandsen, J. B.; Mier-Torrecilla, M.; Zurita-Gotor, M.; Holman, D. M.

    2012-04-01

    The focus of the present free-surface model developments is to utilize gas dynamics theory to predict and investigate underlying mechanisms of the dynamics of nonlinear water waves. Since water wave mechanics is a topic not concerned with the notions from thermodynamics, the basics of the physics of incompressible gas dynamics provides a relatively simple means for describing the theory and predictions of nonlinear wave propagation through advanced random and nonlinear particle collision processes [1]. Nonlinear free-surface physics are investigated using the Lattice Boltzmann Method (LBM) at intermediate to shallow water depth. The LBM simulates fluid flow by tracking particle distributions in a Lagrangian manner. The particles are constrained to move on regular or octree lattices depending on wave steepness and/or wave-structure interaction details sought. The Boltzmann equation relates the time evolution and spatial variation of a collection of molecules to a collision operator that describes the interaction of the molecules. Mathematically, the collision integral of the LB equation poses difficulties when solution of the equation is sought. Investigators overcome this through descriptions of models with different levels of accuracy in the approximations of the integral. We consider a model in which the collision assumption is approximated by a multiple relaxation time form. The free-surface algorithm involves an interface tracking scheme based on the volume fraction of the fluid combined with the LBM for the advection equation in which the solver reconstructs the missing probability distribution functions taking into account the distance to the interface [2, 3]. The approximate forms of the LBM describe comparisons of the nonlinear shallow water equations and the Navier Stokes equations. Test cases involving predictions of run-up/run-down on cylinders and beaches are shown. The wet-dry interface conditions, viscosity treatment, surface break-up amongst others

  4. High spatio-temporal resolution PIV of laminar boundary layer relaxation instability at the free surface of a jet

    NASA Astrophysics Data System (ADS)

    Andre, Matthieu; Bardet, Philippe

    2012-11-01

    In high-speed free surface flows, microscale instabilities can lead to dramatic macroscale effects such as waves, breakup, or air entrainment. The importance of jets in practical applications requires a better understanding of the mechanisms leading to these instabilities. This experimental study focuses on laminar boundary layer relaxation (LBLR) instability. This has received fewer attention than other instabilities due to the small scale, the high Reynolds number and the proximity of an interface. The experiment features a 20 . 3 mm × 146 . 0 mm laminar slab wall jet exiting a nozzle into quiescent air (Re= 3 . 1 ×104 to 1 . 6 ×105). The free surface is flat near the nozzle exit then the LBLR leads to 2D capillary waves which can become very steep eventually resulting in primary breakup and air entrainment. The inception and growth of the capillaries are investigated using time-resolved PIV coupled with PLIF to track the free surface. A magnification of 4 allows a spatial and temporal resolution better than 0.1mm and 0.1ms, respectively. These high resolution results show the role of vortices -created by the roll-up of the shear layer below the surface- in the formation of capillaries. Vortices and waves are a coupled system; the waves can sustain, damp, or amplify. This study has been supported by the start-up funds from The George Washington University to Dr. Bardet.

  5. Nonlinear simulation of free surfaces and atomization in pressure swirl atomizers

    NASA Astrophysics Data System (ADS)

    Park, Hongbok; Heister, Stephen D.

    2006-05-01

    A fully nonlinear boundary element method (BEM) model has been developed to simulate the pressure swirl or simplex atomizer. The free surface inside the vortex chamber and within the hollow-cone/primary atomization zone is simulated with a fourth order scheme thereby permitting investigation of highly distorted surfaces up to the point where atomization occurs. For the axisymmetric calculations, annular rings of fluid are pinched from the main liquid domain. Swirling flow is simulated via a superposition of a potential vortex with the base axial flow emanating from the nozzle in a BEM formulation. Results show good comparison to film thicknesses from test data as well as from linear one-dimensional theory. Parametric studies are conducted to assess the influence of injector geometry and flow characteristics on film thickness and spray angle produced by the atomizer. Limited results are also provided to compare droplet sizes with experimental data. In this regard, the linear stability analysis of Ponstein is used to predict the number of droplets created from each ring of fluid shed by the axisymmetric calculation.

  6. Topologies of velocity-field stagnation points generated by a single pair of magnets in free-surface electromagnetic experiments.

    PubMed

    de la Cruz, J M García; Vassilicos, J C; Rossi, L

    2014-10-01

    The velocity fields generated by a static pair of magnets in free-surface electromagnetically forced flows are analyzed for different magnet attitudes, ionic currents, and brine depths. A wide range of laminar velocity fields is obtained despite the forcing simplicity. The velocity fields are classified according to their temporal mean flow topology, which strongly depends on the forcing geometry but barely on its strength, even through the bifurcation to unsteady regimes. The mean flow topology possesses a major influence on the critical Reynolds number Rec under which the steady velocity fields remain stable. The qualitative comparison of the dependence of Rec on the topology is in agreement with previous works. The unsteady configurations evidence the advection of smaller flow structures by the largest scales, commonly known as "sweeping."

  7. Topologies of velocity-field stagnation points generated by a single pair of magnets in free-surface electromagnetic experiments

    NASA Astrophysics Data System (ADS)

    de la Cruz, J. M. García; Vassilicos, J. C.; Rossi, L.

    2014-10-01

    The velocity fields generated by a static pair of magnets in free-surface electromagnetically forced flows are analyzed for different magnet attitudes, ionic currents, and brine depths. A wide range of laminar velocity fields is obtained despite the forcing simplicity. The velocity fields are classified according to their temporal mean flow topology, which strongly depends on the forcing geometry but barely on its strength, even through the bifurcation to unsteady regimes. The mean flow topology possesses a major influence on the critical Reynolds numberRec under which the steady velocity fields remain stable. The qualitative comparison of the dependence of Rec on the topology is in agreement with previous works. The unsteady configurations evidence the advection of smaller flow structures by the largest scales, commonly known as "sweeping."

  8. RTM-based Teleseismic Reflection Tomography with Free Surface Multiples

    NASA Astrophysics Data System (ADS)

    Burdick, S. A.; De Hoop, M. V.; van der Hilst, R. D.

    2013-12-01

    Receiver function analysis of teleseismic converted and free surface reflected phases has long been a cornerstone of lithospheric studies. Discontinuities in elastic properties are revealed by deconvolving the incident wavefield from scattered phases and projecting the time differences to depth to form an image. The accuracy of the image is determined to a large extent by the accuracy of the method and background velocity model used, but popular approaches for projecting receiver functions to depth commonly rely on simplifying assumptions of a 1D velocity and planar discontinuities. In tectonically complex regions like subduction zones and rift systems, strong heterogeneity can create an ambiguous tradeoff between the background velocity and the depth of the discontinuities. Furthermore, such structures are apt to create caustics at high frequencies, rendering ray-based methods inadequate. In order to better constrain the background velocity and correctly place the discontinuities at depth, we employ a novel reverse-time migration (RTM) based reflection tomography method. We adapt our reflection tomography from exploration seismology for use with teleseismic phases. Active source methods for exploration have focused on the annihilation of extended images - image gathers formed with different subsurface angle or offset information - as a means of judging the accuracy of the model. Applying these approaches to teleseismic data is untenable because 1) the sparse and uneven distribution of earthquake sources leads to the incomplete construction of extended image, 2) the imperfect separation and source deconvolution of the scattered wavefield render previous error measurements unreliable, and 3) the planar geometry of incoming arrivals makes measures of subsurface offset insensitive to perturbations in the model. To overcome these obstacles, we have developed a flexible approach based on pairwise single-source image correlations. We determine the success of the RTM and

  9. Free-surface stability criterion as affected by velocity distribution

    USGS Publications Warehouse

    Cheng-Lung, Chen

    1995-01-01

    This paper examines how the velocity distribution of flow in open channels affects the kinematic and dynamic wave velocities, from which the various forms of the Vedernikov number V can be formulated. When V >1, disturbances created in open-channel flow will amplify in the form of roll waves; when V <1, some (though not all) disturbances will attenuate. A study of the Vedernikov stability criterion reveals that it can be readily deduced within the framework of the kinematic and dynamic wave theories by comparing the kinematic wave velocity to the corresponding dynamic wave velocity. -from Author

  10. Free surface modeling in OWC chamber with parabolic side walls using 3D BEM

    SciTech Connect

    Hasanabad, Madjid Ghodsi

    2015-03-10

    In this paper, BEM was used for free surface modeling in OWC chamber and out of it. Linear kinematic and dynamic boundary conditions were used for free surface out of OWC chamber and nonlinear forms were used for free surface in the chamber. These boundary conditions were discretized by finite differences method. Also, some thermodynamics relations were applied for trapped air behavior modeling in OWC chamber. Wave specifications in Chabahar region were used in modeling because these waves have an acceptable power for electricity generation. The results show a good agreement with results of other researches.

  11. Design procedures for flutter-free surface panels

    NASA Technical Reports Server (NTRS)

    Laurenson, R. M.; Mcpherson, J. I.

    1977-01-01

    An approach for the design of lightweight external surface panel configurations to preclude panel flutter was developed. Design procedures were developed for flat orthotropic panels under the interacting influence of parameters such as support flexibility, inplane loads, pressure differential, and flow angularity. The basic relationships required to define these design procedures were based on theoretical panel flutter analyses. Where possible, the design procedures were verified through comparison with available experimental panel flutter data.

  12. Numerical modeling of free surface and rapid solidification for simulation and analysis of melt spinning

    NASA Astrophysics Data System (ADS)

    Wang, Chunbai

    The work provides methodologies for studying, designing, and optimizing melt spinning processes of fiber manufacture. Amorphous metallic materials can be created through melt spinning processes, in which a highly spinning wheel undercools a jet of molten metal or alloy below the equilibrium melting and the nucleation temperatures. Free-jet melt spinning employs a larger nozzle-wheel gap compared to planar flow casting. The instability of melt pool formation in a free-jet melt spinning will allow the variability of ribbon production. In general, a stable delivery of amorphous materials depends simultaneously on various control parameters, such as wheel speed, molten flow viscosity, surface tension force, and heat transfer. To analyze dynamical and thermodynamical characteristics of a free-jet melt spinning, two mathematical models, free surface and rapid solidification, have been established by means of Computational Fluid Dynamics. Based on the nucleation theory, I have predicted the nucleation temperature and the critical cooling rate for an alloy Fe75-Si10-B15 (at.%). The applications of these crystalline solidification properties in the simulation and analysis help the researchers gain insight into the processes. The research focuses on a novel simple and second-order accurate algorithm for computing surface normal and curvature in the Volume of Fluid method; it reconstructs the continuum surface force model to eliminate spurious currents. A computer program has been developed with the enhanced numerical schemes and the capability of heat transfer for two-dimensional laminar Newtonian surface flows. It conducted numerical simulations of impingement of a melt stream against a highly rotating wheel, and explains the complicated processes with numerical results of velocity and temperature in melt pools. The analytical estimates of ribbon thickness presented in the thesis agree with the experimental observation of the alloy. An in-depth investigation of the melt

  13. Micro-swimmer dynamics in free-surface turbulence subject to wind stress

    NASA Astrophysics Data System (ADS)

    Marchioli, Cristian; Lovecchio, Salvatore; Soldati, Alfredo

    2015-11-01

    We examine the effect of wind-induced shear on the orientation and distribution of motile micro-swimmers in free-surface turbulence. Winds blowing above the air-water interface can influence the distribution and productivity of motile organisms via the shear generated just below the surface. Swimmer dynamics depend not only by the advection of the fluid but also by external stimuli like nutrient concentration, light, gravity. Here we focus on gyrotaxis, resulting from the gravitational torque generated by an asymmetric mass distribution within the organism. The combination of such torque with the viscous torque due to shear can reorient swimmers, reducing their vertical migration and causing entrapment in horizontal fluid layers. Through DNS-based Euler-Lagrangian simulations we investigate the effect of wind-induced shear on the motion of gyrotactic swimmers in turbulent open channel flow. We consider different wind directions and swimmers with different reorientation time (reflecting the ability to react to turbulent fluctuations). We show that only stable (high-gyrotaxis) swimmers may reach the surface and form densely concentrated filaments, the topology of which depends on the wind direction. Otherwise swimmers exhibit weaker vertical fluxes and segregation at the surface.

  14. Method and apparatus to produce and maintain a thick, flowing, liquid lithium first wall for toroidal magnetic confinement DT fusion reactors

    DOEpatents

    Woolley, Robert D.

    2002-01-01

    A system for forming a thick flowing liquid metal, in this case lithium, layer on the inside wall of a toroid containing the plasma of a deuterium-tritium fusion reactor. The presence of the liquid metal layer or first wall serves to prevent neutron damage to the walls of the toroid. A poloidal current in the liquid metal layer is oriented so that it flows in the same direction as the current in a series of external magnets used to confine the plasma. This current alignment results in the liquid metal being forced against the wall of the toroid. After the liquid metal exits the toroid it is pumped to a heat extraction and power conversion device prior to being reentering the toroid.

  15. The Peierls stress for coupled dislocation partials near a free surface

    NASA Astrophysics Data System (ADS)

    Gars, Benoit; Markenscoff, Xanthippi

    2012-04-01

    The effect of a free surface on the Peierls stress of a perfect dislocation, as well as on one of two dislocation partials under a free surface, has been accounted for by considering the Lubarda-Markenscoff variable-core dislocation model (VCM). The VCM dislocation smears the Burgers vector, while producing on the slip plane the Peierls-Nabarro sinusoidal relation between the stress and the slip discontinuity with a variable width. Here the core radius is allowed to depend on the distance to the free surface and the other partial. The Peierls stress is computed as a configurational force by accounting for all the energies and the image stresses to satisfy the traction-free boundary conditions. The results are applied to aluminum and copper and comparisons are made with atomistic calculations in the literature that show that the partials merge as they approach the free surface.

  16. A free surface capturing discretization for the staggered grid finite difference scheme

    NASA Astrophysics Data System (ADS)

    Duretz, T.; May, D. A.; Yamato, P.

    2016-03-01

    The coupling that exists between surface processes and deformation within both the shallow crust and the deeper mantle-lithosphere has stimulated the development of computational geodynamic models that incorporate a free surface boundary condition. We introduce a treatment of this boundary condition that is suitable for staggered grid, finite difference schemes employing a structured Eulerian mesh. Our interface capturing treatment discretizes the free surface boundary condition via an interface that conforms with the edges of control volumes (e.g. a `staircase' representation) and requires only local stencil modifications to be performed. Comparisons with analytic solutions verify that the method is first-order accurate. Additional intermodel comparisons are performed between known reference models to further validate our free surface approximation. Lastly, we demonstrate the applicability of a multigrid solver to our free surface methodology and demonstrate that the local stencil modifications do not strongly influence the convergence of the iterative solver.

  17. 46 CFR 170.295 - Special consideration for free surface of passive roll stabilization tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) for a stabilization tank may be reduced in accordance with the following equation: E.F.S.=(K)(F.F.S.) where— E.F.S.=the effective free surface. F.F.S.=the full free surface calculated in accordance with...) The factor (K) must be calculated as follows: (1) Plot (I/d)tan T on Graph 170.295 where— (i) (I)...

  18. 46 CFR 170.295 - Special consideration for free surface of passive roll stabilization tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) for a stabilization tank may be reduced in accordance with the following equation: E.F.S.=(K)(F.F.S.) where— E.F.S.=the effective free surface. F.F.S.=the full free surface calculated in accordance with...) The factor (K) must be calculated as follows: (1) Plot (I/d)tan T on Graph 170.295 where— (i) (I)...

  19. Statistics of particle concentration in free-surface turbulence

    SciTech Connect

    Bandi, Mahesh M; Larkin, J; Goldburg, W

    2009-01-01

    Particles on the surface of an incompressible fluid maintained in a turbulent steady-state cluster into spatio-temporally complex flow structures. We experimentally study the statistics of particle concentration n(r, t) over various coarse-grained scales r' in the inertial range. Another control parameter is the Taylor Microscale Reynolds number Re{sub {lambda}}. The focus is on the steady state probability density function {Pi}(n{sub r}). Attention is also given to the variance {sigma}{sup 2}(r, t) of this PDF, since it yields information about the topology of the coagulated structures. Where possible, the results are compared and contrasted with those obtained in a recent analytical and numerical study of two-dimensional synthetic turbulence by Ducasse and Pumir. There, but not here, the dimensionless compressibility C is an important control parameter.

  20. Interaction of two spark-generated bubbles near a confined free surface

    NASA Astrophysics Data System (ADS)

    Saleki-Haselghoubi, Noureyeh; Shervani-Tabar, Mohammad Taghi; Taeibi-Rahni, Mohammad; Dadvand, Abdolrahman

    2016-06-01

    In this paper, the oscillation of two spark-generated bubbles placed on a vertical column in close proximity to a confined free surface is considered. The confined free surface is accorded by the top opening of different configurations. These configurations include (i) a centrally perforated horizontal flat plate ({θ=90°)}, (ii) vertically placed cylinder ({θ=0°)} and (iii) nozzle ({θ >0°)}. The main objective of the present work is to study the effects of key parameters such as the nozzle geometry, the locations of the energy input (i.e., initial position of the bubbles with respect to each other and relative to the free surface) on the dynamics of the two bubbles and the free surface. It was found that the lifetime of the upper bubble decreases from the vertical cylinder to the flat plate case. In addition, by reducing the inter-bubble distance, the lifetime of the upper bubble becomes longer and the repulsion between two bubbles during the expansion phase is stronger. Finally, by reducing the upper bubble-free surface distance, the repulsion between two bubbles during expansion phase increases, the tendency of the upper bubble to rebound and initiate another oscillation cycle decreases, and the amplitude of elevation of the free surface increases.

  1. Thermo-mechanically coupled subduction with a free surface using ASPECT

    NASA Astrophysics Data System (ADS)

    Fraters, Menno; Glerum, Anne; Thieulot, Cedric; Spakman, Wim

    2014-05-01

    ASPECT (Kronbichler et al., 2012), short for Advanced Solver for Problems in Earth's ConvecTion, is a new Finite Element code which was originally designed for thermally driven (mantle) convection and is built on state of the art numerical methods (adaptive mesh refinement, linear and nonlinear solver, stabilization of transport dominated processes and a high scalability on multiple processors). Here we present an application of ASPECT to modeling of fully thermo-mechanically coupled subduction. Our subduction model contains three different compositions: a crustal composition on top of both the subducting slab and the overriding plate, a mantle composition and a sticky air composition, which allows for simulating a free surface for modeling topography build-up. We implemented a visco-plastic rheology using frictional plasticity and a composite viscosity defined by diffusion and dislocation creep. The lithospheric mantle has the same composition as the mantle but has a higher viscosity because of a lower temperature. The temperature field is implemented in ASPECT as follows: a linear temperature gradient for the lithosphere and an adiabatic geotherm for the sublithospheric mantle. Initial slab temperature is defined using the analytical solution of McKenzie (1970). The plates can be pushed from the sides of the model, and it is possible to define an additional independent mantle in/out flow through the boundaries. We will show a preliminary set of models, highlighting the codes capabilities, such as the Adaptive Mesh Refinement, topography development and the influence of mantle flow on the subduction evolution. Kronbichler, M., Heister, T., and Bangerth, W. (2012), High accuracy mantle convection simulation through modern numerical methods, Geophysical Journal International,191, 12-29, doi:10.1111/j.1365-246X.2012.05609. McKenzie, D.P. (1970), Temperature and potential temperature beneath island arcs, Teconophysics, 10, 357-366, doi:10.1016/0040-1951(70)90115-0.

  2. Stresses due to Squeeze Flow between Particles Surrounded by an Electrolyte Solution with Application to Lithium-Ion Batteries

    NASA Astrophysics Data System (ADS)

    Conlisk, A. T.; Zhang, Cong

    2013-11-01

    Large stresses are induced during lithium-ion battery charging and discharging, termed intercalation and deintercalation stresses. Current models of the stresses in lithium-ion batteries in the literature seldom consider the influence of the interaction between the particles within the electrodes on the stress distribution. The particles within lithium-ion battery electrodes can undergo relative motion with relative velocities of different magnitudes and directions. One important mode of motion manifests itself as two particles approaching each other. The interaction is mediated by the electrolyte between the particles. The relative motion of the particles induces significant pressures and the primary objective of this work is to propose a source of mechanical stresses as a consequence of the dynamic squeezing motion as opposed to a static environment considered in the battery literature. Other applications in the biomedical field are also discussed. Supported by DOE Graduate Automotive Technology Education (GATE), OSU Center for Automotive Research and OSU NSEC Center for the Affordable Nanoengineering of Polymeric Biomedical Devices.

  3. Hydrogen, lithium, and lithium hydride production

    DOEpatents

    Brown, Sam W; Spencer, Larry S; Phillips, Michael R; Powell, G. Louis; Campbell, Peggy J

    2014-03-25

    A method of producing high purity lithium metal is provided, where gaseous-phase lithium metal is extracted from lithium hydride and condensed to form solid high purity lithium metal. The high purity lithium metal may be hydrided to provide high purity lithium hydride.

  4. On the Finite-Time Splash and Splat Singularities for the 3-D Free-Surface Euler Equations

    NASA Astrophysics Data System (ADS)

    Coutand, Daniel; Shkoller, Steve

    2014-01-01

    We prove that the 3-D free-surface incompressible Euler equations with regular initial geometries and velocity fields have solutions which can form a finite-time "splash" (or "splat") singularity first introduced in Castro et al. (Splash singularity for water waves, http://arxiv.org/abs/1106.2120v2, 2011), wherein the evolving 2-D hypersurface, the moving boundary of the fluid domain, self-intersects at a point (or on surface). Such singularities can occur when the crest of a breaking wave falls unto its trough, or in the study of drop impact upon liquid surfaces. Our approach is founded upon the Lagrangian description of the free-boundary problem, combined with a novel approximation scheme of a finite collection of local coordinate charts; as such we are able to analyze a rather general set of geometries for the evolving 2-D free-surface of the fluid. We do not assume the fluid is irrotational, and as such, our method can be used for a number of other fluid interface problems, including compressible flows, plasmas, as well as the inclusion of surface tension effects.

  5. Improved free-surface expression for frequency-domain elastic optimal mixed-grid modeling

    NASA Astrophysics Data System (ADS)

    Cao, Jian; Chen, Jing-Bo; Dai, Meng-Xue

    2016-07-01

    An accurate and efficient forward modeling is the foundation of full-waveform inversion (FWI). In elastic wave modeling, one of the key problems is how to deal with the free-surface boundary condition appropriately. For the representation of the free-surface boundary condition, conventional displacement-based approaches and staggered-grid approaches are often used in time-domain. In frequency-domain, considering the saving of storage and CPU time, we integrate the idea of physical parameter-modified staggered-grid approach in time-domain with an elastic optimal mixed-grid modeling scheme to design an improved parameter-modified free-surface expression. Accuracy analysis shows that an elastic optimal mixed-grid modeling scheme using the parameter-modified free-surface expression can provide more accurate solutions with only 4 grid points per smallest shear wavelength than conventional displacement-based approaches and is stable for most Poisson ratios. Besides, it also yields smaller condition number of the resulting impedance matrix than conventional displacement-based approaches in laterally varying complex media. These advantages reveal great potential of this free-surface expression in big-data practical application.

  6. Thermoelectric magnetohydrodynamic and thermocapillary driven flows of liquid conductors in magnetic fields

    NASA Astrophysics Data System (ADS)

    Jaworski, Michael Andrew

    The Solid/Liquid Lithium Divertor experiment (SLiDE) has been designed, constructed and operated in order to determine the behavior of these liquid conductors in a magnetic field with imposed thermal gradients. Liquid lithium is chosen for its applicability to fusion systems as well as recent demonstrations of its ability to passively redistribute incident heat fluxes on the order of 50[MW/m2]. The lithium is contained within a stainless steel tray that is actively cooled and contains a set of temperature diagnostics for analysis of the heat, flux coming from the tray. The system is magnetized by a set of external magnets and a linear electron beam is used to create heat fluxes similar to those found in fusion divertors. Surface velocity of the liquid lithium is measured with a digital camera. A theory explaining the balance between thermoelectric magnetohydrodynamics and thero-capillary driven, free-surface flows in containers of arbitrary type in a magnetized environment has been developed. A new dimensionless group depending on the thermoelectric power of the liquid/container pair, the physical properties of the liquid and solid and the flow geometry has been found that determines which mechanism, TC or TEMHD, is the dominant effect in any given system. Experiments show that TEMHD dominates the flow in SLiDE, consistent with the theory governing these flows. This is verified by series of qualitative experiments, as well as quantitative comparison with theoretical flow predictions. This constitutes the first direct observation of TEMHD driven flow yet reported in the literature. Application of the developed theory indicates liquid lithium fusion systems will operate in a TEMHD dominated regime. Technologies suggested by the exploitation of TEMHD pumping are also presented.

  7. Simulation of a free-surface and seepage face using boundary-fitted coordinate system method

    NASA Astrophysics Data System (ADS)

    Lee, Kang-Kun; Leap, Darrell I.

    1997-09-01

    The boundary-fitted coordinate (BFC) system method is applied to simulate steady groundwater seepage with a free-surface and seepage face using the finite-difference method. The BFC system method eliminates the difficulty of fitting finite-difference grids to a changeable free-surface which is not known a priori but will be obtained as part of a solution. Also, grid generation with this approach is simpler than with the finite-element method. At each iterative sweep, the changeable free-surface becomes a part of the boundary-fitted grid lines, making boundary condition implementation easy and accurate. An example problem demonstrating the simulation procedure and numerical results compares very well with the analytical solution.

  8. Nucleation of cracks near the free surface in deformed metallic nanomaterials with a bimodal structure

    NASA Astrophysics Data System (ADS)

    Ovid'ko, I. A.; Sheinerman, A. G.

    2016-06-01

    A theoretical model that effectively describes the nucleation of cracks in stress fields of dislocation pile-ups near the free surface in metallic nanomaterials with a bimodal structure has been developed. The dependences of the critical shear stress τ c (for the formation of a crack with an equilibrium length of 10 nm on a dislocation pile-up near the surface) on the size d of a grain containing the dislocation pile-up have been calculated for copper with a bimodal structure. Theoretically, it has been found that the critical shear stress τ c for the nucleation of a crack near the free surface in a nanomaterial with a bimodal structure is approximately 30% higher than that for the crack nucleation within the nanomaterial at a distance from the free surface.

  9. 3D numerical simulation analysis of passive drag near free surface in swimming

    NASA Astrophysics Data System (ADS)

    Zhan, Jie-min; Li, Tian-zeng; Chen, Xue-bin; Li, Yok-sheung; Wai, Wing-hong Onyx

    2015-04-01

    The aim of this work is to build a 3D numerical model to study the characteristics of passive drag on competitive swimmers taking into account the impact of the free surface. This model solves the 3D incompressible Navier-Stokes equations using RNG k- ɛ turbulence closure. The volume of fluid (VOF) method is used to locate the free surface. The 3D virtual model is created by Computer Aided Industrial Design (CAID) software, Rhinoceros. Firstly, a specific posture of swimming is studied. The simulation results are in good agreement with the data from mannequin towing experiments. The effects of a swimmer's arms and legs positions on swimming performance are then studied. Finally, it is demonstrated that the present method is capable of simulating gliding near the free surface.

  10. Combustion theory for liquids with a free surface. 3: Special problems

    NASA Technical Reports Server (NTRS)

    Milkov, S. N.; Sukhov, G. S.; Yarin, L. P.

    1986-01-01

    Two special problems concerning the combustion of liquids with a free surface, i.e., flame quenching during the mixing of a burning liquid inside a container and liquid burnout from a porous layer, are analyzed using a quasi-one-dimensional model. The critical parameters corresponding to the quenching of a burning fluid with a free surface are determined. Determinations are also made of the limiting pressure gradients corresponding to the transition from the combustion mode where the liquid evaporates from the surface of a porous layer to the mode where the phase transition surface lies inside the porous layer.

  11. Curvature estimation from a volume-of-fluid indicator function for the simulation of surface tension and wetting with a free-surface lattice Boltzmann method.

    PubMed

    Bogner, Simon; Rüde, Ulrich; Harting, Jens

    2016-04-01

    The free surface lattice Boltzmann method (FSLBM) is a combination of the hydrodynamic lattice Boltzmann method with a volume-of-fluid (VOF) interface capturing technique for the simulation of incompressible free surface flows. Capillary effects are modeled by extracting the curvature of the interface from the VOF indicator function and imposing a pressure jump at the free boundary. However, obtaining accurate curvature estimates from a VOF description can introduce significant errors. This article reports numerical results for three different surface tension models in standard test cases and compares the according errors in the velocity field (spurious currents). Furthermore, the FSLBM is shown to be suited to simulate wetting effects at solid boundaries. To this end, a new method is developed to represent wetting boundary conditions in a least-squares curvature reconstruction technique. The main limitations of the current FSLBM are analyzed and are found to be caused by its simplified advection scheme. Possible improvements are suggested. PMID:27176423

  12. Upwind-biased FORCE schemes with applications to free-surface shallow flows

    NASA Astrophysics Data System (ADS)

    Stecca, Guglielmo; Siviglia, Annunziato; Toro, Eleuterio F.

    2010-09-01

    In this paper we develop numerical fluxes of the centred type for one-step schemes in conservative form for solving general systems of conservation laws in multiple-space dimensions on structured meshes. The proposed method is an extension of the multidimensional FORCE flux developed by Toro et al. (2009) [14]. Here we introduce upwind bias by modifying the shape of the staggered mesh of the original FORCE method. The upwind bias is evaluated using an estimate of the largest eigenvalue, which in any case is needed for selecting a time step. The resulting basic flux is first-order accurate and monotone. For the linear advection equation, the proposed UFORCE method reproduces exactly the upwind Godunov method. Extension to non-linear systems has been done empirically via the two-dimensional inviscid shallow water equations. Second order of accuracy in space and time on structured meshes is obtained in the framework of finite volume methods. The proposed method improves the accuracy of the solution for small Courant numbers and intermediate waves associated with linearly degenerate fields (contact discontinuities, shear waves and material interfaces). It achieves comparable accuracy to that of upwind methods with approximate Riemann solvers, though retaining the simplicity and efficiency of centred methods. The performance of the schemes is assessed on a suite of test problems for the two-dimensional shallow water equations.

  13. Optimal dispersion with minimized Poisson equations for non-hydrostatic free surface flows

    NASA Astrophysics Data System (ADS)

    Cui, Haiyang; Pietrzak, J. D.; Stelling, G. S.

    2014-09-01

    A non-hydrostatic shallow-water model is proposed to simulate the wave propagation in situations where the ratio of the wave length to the water depth is small. It exploits the reduced-size stencil in the Poisson pressure solver to make the model less expensive in terms of memory and CPU time. We refer to this new technique as the minimized Poisson equations formulation. In the simplest case when the method applied to a two-layer model, the new model requires the same computational effort as depth-integrated non-hydrostatic models, but can provide a much better description of dispersive waves. To allow an easy implementation of the new method in depth-integrated models, the governing equations are transformed into a depth-integrated system, in which the velocity difference serves as an extra variable. The non-hydrostatic shallow-water model with minimized Poisson equations formulation produces good results in a series of numerical experiments, including a standing wave in a basin, a non-linear wave test, solitary wave propagation in a channel and a wave propagation over a submerged bar.

  14. Free-surface flow in horizontally rotating cylinder: experiment and simulation

    NASA Astrophysics Data System (ADS)

    Bohacek, J.; Kharicha, A.; Ludwig, A.; Wu, M.; Paar, A.; Brandner, M.; Elizondo, L.; Trickl, T.

    2016-07-01

    The horizontal centrifugal casting process targets on a liquid layer with a uniform thickness. To achieve this, the rotations of the mold have to be large enough so that the liquid can pick up the speed of the mold. In the present paper, an experiment was conducted using a laboratory plexi-glass mold with water as a working fluid. Starting with an initial volume fraction of liquid resting in the bottom of the mold, the mold rotations were gradually increased from 0 rpm to max rpm and a new position of the contact line was recorded. In addition, first critical rpm was recorded, at which the transition from the liquid pool to a uniform liquid layer occurred. While gradually going back from max rpm to 0 rpm, second critical rpm was recorded, at which the uniform liquid layer collapsed. The experiment was compared with the numerical simulation solving the modified shallow water equations using the Newton-Raphson method with the Wallington filter.

  15. Low gravity experiment for studying a rotating fluid having a free surface

    NASA Technical Reports Server (NTRS)

    Holderer, O. C.

    1983-01-01

    Electrical, mechanical, and operational aspects of a test cell assembly for studying rotating fluids with a free surface are described. Results of a stress analysis prepared to document the structural adequacy for safe use on the KC-135 aircraft are presented along with results of a single load proof test of the most critical load case. Engineering drawings are included.

  16. Lithium toxicity

    MedlinePlus

    ... dialysis (machine) Medicines to treat symptoms Whole bowel irrigation with a special solution taken by mouth or through a tube through the nose into the stomach (to flush sustained-release lithium quickly through the stomach and intestines)

  17. Heat and mass transfer at a free surface with diabatic boundaries in a single-species system under microgravity conditions

    NASA Astrophysics Data System (ADS)

    Fuhrmann, Eckart; Dreyer, Michael E.

    2014-06-01

    In this paper, we analyzed the heat and mass transfer at a free surface under microgravity conditions. The SOURCE-II (Sounding Rocket COMPERE Experiment) experiment was performed on a suborbital flight in February 2012 from Esrange in North Sweden. It provided representative data with respect to solid, liquid, and vapor temperatures as well as the visible surface position. The objectives were to quantify the deformation of the free liquid surface and to correlate the apparent contact angle to a characteristic temperature difference between subcooled liquid and superheated wall. Furthermore, the influence of evaporation and condensation at the liquid/vapor interface and at the superheated wall must be taken into account to analyze heat and mass fluxes due to a characteristic temperature difference. In the following, we show evidently that the magnitude of the apparent contact angle depends on the exerted specific pressurizations of the vapor phase during the experiment and hence on the change in the saturation temperature at the free surface. The characteristic temperature difference is defined with respect to the wall temperature in the vicinity of the contact line and the saturation temperature. Therefore, apparent contact angle and temperature difference can be correlated and indicate a specific characteristic. Concerning the heat and mass transfer at the free liquid surface and the contact line, two different methods are presented to evaluate the net mass due to phase change within a certain time interval. In the first approach, the mass flow rate is calculated by means of the ideal gas law and its derivatives with respect to temperature and pressure. The second approach calculates the heat flux as well as the mass flux at the wall and in the region of the free liquid surface. In these cases, a specific heat transfer coefficient and a thermal boundary layer thickness are used.

  18. Free-surface microfluidic control of surface-enhanced Raman spectroscopy for the optimized detection of airborne molecules

    PubMed Central

    Piorek, Brian D.; Lee, Seung Joon; Santiago, Juan G.; Moskovits, Martin; Banerjee, Sanjoy; Meinhart, Carl D.

    2007-01-01

    We present a microfluidic technique for sensitive, real-time, optimized detection of airborne water-soluble molecules by surface-enhanced Raman spectroscopy (SERS). The method is based on a free-surface fluidic device in which a pressure-driven liquid microchannel flow is constrained by surface tension. A colloidal suspension of silver nanoparticles flowing through the microchannel that is open to the atmosphere absorbs gas-phase 4-aminobenzenethiol (4-ABT) from the surrounding environment. As surface ions adsorbed on the colloid nanoparticles are substituted by 4-ABT, the colloid aggregates, forming SERS “hot spots” whose concentrations vary predictably along the microchannel flow. 4-ABT confined in these hot spots produces SERS spectra of very great intensity. An aggregation model is used to account quantitatively for the extent of colloid aggregation as determined from the variation of the SERS intensity measured as a function of the streamwise position along the microchannel, which also corresponds to nanoparticle exposure time. This allows us to monitor simultaneously the nanoparticle aggregation process and to determine the location at which the SERS signal is optimized. PMID:18025462

  19. Lithium Ion Battery Design and Safety

    NASA Technical Reports Server (NTRS)

    Au, George; Locke, Laura

    2001-01-01

    This viewgraph presentation makes several recommendations to ensure the safe and effective design of Lithium ion cell batteries. Large lithium ion cells require pressure switches and small cells require pressure disconnects and other safety devices with the ability to instantly interrupt flow. Other suggestions include specifications for batteries and battery chargers.

  20. The fabrication of a vanadium-stainless steel test section for MHD testing of insulator coatings in flowing lithium

    SciTech Connect

    Reed, C.B.; Mattas, R.F.; Smith, D.L.; Chung, H.; Tsai, H.-C.; Morgan, G.D.; Wille, G.W.; Johnson, W.R.; Young, C.

    1996-12-31

    To test the magnetohydrodynamic (MHD) pressure drop reduction performance of candidate insulator coatings for the ITER Vanadium/Lithium Breeding Blanket, a test section comprised of a V- 4Cr-4Ti liner inside a stainless steel pipe was designed and fabricated. Theoretically, the MHD pressure drop reduction benefit resulting, from an electrically insulating coating on a vanadium- lined pipe is identical to the benefit derived from an insulated pipe fabricated of vanadium alone. A duplex test section design consisting of a V alloy liner encased in a SS pressure boundary provided protection for vanadium from atmospheric contamination during operation at high temperature and obviated any potential problems with vanadium welding while also minimizing the amount of V alloy material required. From the MHD and insulator coating- point of view, the test section outer SS wall and inner V alloy liner can be modeled simply as a wall having a sandwich construction. Two 52.3 mm OD x 2.9 m long V-alloy tubes were fabricated by Century Tubes from 64 mm x 200 mm x 1245 mm extrusions produced by Teledyne Wah Chang. The test section`s duplex structure was subsequently fabricated at Century Tubes by drawing down a SS pipe (2 inch schedule 10) over one of the 53.2 mm diameter V tubes.

  1. Analysis of a Free Surface Film from a Controlled Liquid Impinging Jet over a Rotating Disk Including Conjugate Effects, with and without Evaporation

    NASA Technical Reports Server (NTRS)

    Sankaran, Subramanian (Technical Monitor); Rice, Jeremy; Faghri, Amir; Cetegen, Baki M.

    2005-01-01

    A detailed analysis of the liquid film characteristics and the accompanying heat transfer of a free surface controlled liquid impinging jet onto a rotating disk are presented. The computations were run on a two-dimensional axi-symmetric Eulerian mesh while the free surface was calculated with the volume of fluid method. Flow rates between 3 and 15 1pm with rotational speeds between 50 and 200 rpm are analyzed. The effects of inlet temperature on the film thickness and heat transfer are characterized as well as evaporative effects. The conjugate heating effect is modeled, and was found to effect the heat transfer results the most at both the inner and outer edges of the heated surface. The heat transfer was enhanced with both increasing flow rate and increasing rotational speeds. When evaporative effects were modeled, the evaporation was found to increase the heat transfer at the lower flow rates the most because of a fully developed thermal field that was achieved. The evaporative effects did not significantly enhance the heat transfer at the higher flow rates.

  2. Segregation Behavior of Sulfur and Other Impurities Onto the Free Surfaces of ED-Ni Deposits

    NASA Technical Reports Server (NTRS)

    Panda, Binayak; Jerman, Gregory; Gentz, Steven J. (Technical Monitor)

    2000-01-01

    Most researchers attribute grain boundary embrittlement in electro-deposited Nickel (ED-Ni) to the presence of small quantities of Sulfur as an impurity. It occurs in a highly mobile form that segregates to the grain boundaries. Evaluation of Sulfur segregation requires that a sample be fractured through the grain boundaries. However, this action may not always be possible. ED-Ni is inherently tough at ambient temperature, especially if a low level of Sulfur was intentionally maintained. A new method was developed to study Sulfur and other migrant species to the grain boundaries, which also migrate to free surfaces. A test specimen is heated by a quartz lamp within the sample preparation chamber, allowing the mobile species to migrate to polished free surfaces. There the mobile species are analyzed using X-ray photoelectron spectroscopy (XPS) also known as Electron Spectroscopy for Chemical Analysis (ESCA).

  3. Segregation Behavior of Sulfur and Other Impurities onto the Free Surfaces of ED-NI Deposits

    NASA Technical Reports Server (NTRS)

    Panda, B.; Jerman, G.

    2001-01-01

    Most researchers attribute grain boundary embrittlement in electro-deposited nickel (ED-Ni) to the presence of small quantities of sulfur as an impurity. It occurs in a highly mobile form that segregates to the grain boundaries. Evaluation of sulfur segregation requires that a sample be fractured through the grain boundaries. However, this action may not always be possible. ED-Ni is inherently tough at ambient temperature, especially if a low level of sulfur was intentionally maintained. A new method was developed to study sulfur and other migrant species to the grain boundaries, which also migrate to free surfaces. A test specimen is heated by a quartz lamp within the sample preparation chamber, allowing the mobile species to migrate to polished free surfaces. There the mobile species are analyzed using X-ray photoelectron spectroscopy (XPS) also known as Electron Spectroscopy for Chemical Analysis (ESCA).

  4. A non-hydrostatic algorithm for free-surface ocean modelling

    NASA Astrophysics Data System (ADS)

    Auclair, Francis; Estournel, Claude; Floor, Jochem W.; Herrmann, Marine; Nguyen, Cyril; Marsaleix, Patrick

    An original implementation of a non-hydrostatic, free-surface algorithm based on a pressure correction method is proposed for ocean modelling. The free surface is implemented through an explicit scheme combined with a mode-spitting method but the depth-averaged velocity and the position of the free surface are updated at each non-hydrostatic iteration. The vertical momentum equation is also integrated up to the surface enabling a natural and accurate treatment of the surface layer. The consistent specification of the numerical schemes provides balanced transfers of potential and kinetic energy. This algorithm is well-suited for implementation as a non-hydrostatic kernel on originally hydrostatic free-surface ocean models such as Symphonie ( http://poc.obs-mip.fr/pages/research_topics/modelling/symphonie/symphonie.htm) for which it has originally been developed. Energy balances associated with the propagation of short surface waves and solitary waves are presented for two dedicated well-documented configurations over closed domains. The buoyancy flux, the work rate of the pressure force together with the power of the advective terms are evaluated and discussed for the generation and the propagation of these two types of waves. The dissipation rate is in particular shown to be several orders of magnitude smaller than the work rates of the hydrostatic and non-hydrostatic pressure forces confirming the necessity for the exchanges of energy to be numerically balanced. The algorithm is subsequently applied to the complex generation of non-linear solitary internal waves by surface tides over Georges Bank, in the Gulf of Maine. The generation and the propagation of the observed non-linear and non-hydrostatic features in this region are correctly reproduced.

  5. Rupture Dynamics Simulations Along Subduction Zones: Bimaterial Interfaces and Free Surface Interaction

    NASA Astrophysics Data System (ADS)

    Scala, A.; Vilotte, J. P.; Festa, G.

    2015-12-01

    Largest earthquakes occur along subduction zones, where normal and tangential stress coupling drives the earthquake rupture due to the geometry of the subduction interface between dissimilar materials and the interaction with waves reflected from free surface as the rupture propagates toward the trench. We numerically investigate these effects in the context of dynamic rupture simulations. We revisit the problem of in-plane interface rupture propagation between dissimilar elastic media, in the case of slip-weakening friction, by performing a numerical study using the Spectral Element Method with a non-smooth contact formulation. For classical slip-weakening friction, the problem is ill posed due to a missing length or time scale in the response of the frictional shear stress to dynamic normal stress perturbations. We first perform a parametric study of the regularization formulation proposed by Rubin and Ampuero (2007). We show that the dynamic regularization, driven by local slip rate does not allow for a proper modeling of the asymptotic rupture propagation. We propose a new regularization approach based on the non-local length scale, associated to the actual size of the process zone. Numerical results are shown to be consistent with mathematical modeling of dynamic interface rupture propagation with a process zone ahead of the rupture front. The numerical study is extended to inclined ruptures intersecting a free surface at different angles. We investigate interaction between rupture propagation and stress changes induced by waves reflected from the free surface, in the generation of large interface slip, transient healing and opening effects. Finally, preliminary in-plane dynamic simulations of the 2011 Tohoku earthquake, incorporating the along-dip structure and geometry of the subduction interface, are presented enlightening the role of the geometry of the bi-material interface and of the free surface in the rupture propagation and radiation.

  6. Liquid-crystalline polymer and block copolymer domain alignment controlled by free-surface segregation.

    PubMed

    Fukuhara, Kei; Fujii, Yasuyoshi; Nagashima, Yuki; Hara, Mitsuo; Nagano, Shusaku; Seki, Takahiro

    2013-06-01

    An orientational change from homeotropic to planar of liquid crystal (LC) mesogens and the microphase separation (MPS) domains is attained by the segregated skin layer at the free surface. This allows for an efficient in-plane photoalignment of the cylindrical domains. The surface segregation strategy is very simple and is therefore expected to open up new possibilities for the orientation control of various types of LC materials. PMID:23616365

  7. Uniform Regularity and Vanishing Viscosity Limit for the Free Surface Navier-Stokes Equations

    NASA Astrophysics Data System (ADS)

    Masmoudi, Nader; Rousset, Frederic

    2016-09-01

    We study the inviscid limit of the free boundary Navier-Stokes equations. We prove the existence of solutions on a uniform time interval by using a suitable functional framework based on Sobolev conormal spaces. This allows us to use a strong compactness argument to justify the inviscid limit. Our approach does not rely on the justification of asymptotic expansions. In particular, we get a new existence result for the Euler equations with free surface from the one for Navier-Stokes.

  8. A 3-D enlarged cell technique (ECT) for elastic wave modelling of a curved free surface

    NASA Astrophysics Data System (ADS)

    Wei, Songlin; Zhou, Jianyang; Zhuang, Mingwei; Liu, Qing Huo

    2016-09-01

    The conventional finite-difference time-domain (FDTD) method for elastic waves suffers from the staircasing error when applied to model a curved free surface because of its structured grid. In this work, an improved, stable and accurate 3-D FDTD method for elastic wave modelling on a curved free surface is developed based on the finite volume method and enlarged cell technique (ECT). To achieve a sufficiently accurate implementation, a finite volume scheme is applied to the curved free surface to remove the staircasing error; in the mean time, to achieve the same stability as the FDTD method without reducing the time step increment, the ECT is introduced to preserve the solution stability by enlarging small irregular cells into adjacent cells under the condition of conservation of force. This method is verified by several 3-D numerical examples. Results show that the method is stable at the Courant stability limit for a regular FDTD grid, and has much higher accuracy than the conventional FDTD method.

  9. Mechanisms of fracture of the free surface of shock-compressed metals

    SciTech Connect

    Mokhova, V. V. Mikhailov, A. L.; Til’kunov, A. V.; Orlov, N. I.; Kanunova, L. I.; Bragunets, V. A.; Tkachenko, M. I.; Simakov, V. G.; Sokolov, S. S.; Podurets, A. M.

    2015-12-15

    The mechanisms of the ejection of aluminum and copper microparticles from the free surfaces of these metals have been studied under conditions of the escape of a moderate-intensity shock wave from a sample. The free surfaces of samples contained 0.7–0.9 mm deep artificial wells and protrusions simulating (on a greater scale of 10: 1) the natural surface roughness retained upon mechanical processing. The pressure in a shock-wave pulse at the base of a protrusion was controlled within P = 5–20 GPa (i.e., below the melting region), and the variable duration of pressure pulses was 0.02, 0.2, and 1 μs. Analysis of the free surfaces of postloaded samples showed that, for certain loading and roughness parameters, the ejection of metal from vertices of protruding ridges or pyramids (as a result of the longitudinal fracture) was about ten times greater than the amount of metal ejected in the form of cumulative jets from wells. The amount of ejected metal and the size distribution of metal microparticles were quantitatively characterized using “soft collecting targets” and by measuring mass losses of samples upon fracture.

  10. A 3-D enlarged cell technique (ECT) for elastic wave modelling of a curved free surface

    NASA Astrophysics Data System (ADS)

    Wei, Songlin; Zhou, Jianyang; Zhuang, Mingwei; Liu, Qing Huo

    2016-07-01

    The conventional finite-difference time-domain (FDTD) method for elastic waves suffers from the staircasing error when applied to model a curved free surface because of its structured grid. In this work, an improved, stable and accurate 3-D FDTD method for elastic wave modelling on a curved free surface is developed based on the finite volume method and enlarged cell technique (ECT). To achieve a sufficiently accurate implementation, a finite volume scheme is applied to the curved free surface to remove the staircasing error; in the mean time, to achieve the same stability as the FDTD method without reducing the time step increment, the ECT is introduced to preserve the solution stability by enlarging small irregular cells into adjacent cells under the condition of conservation of force. This method is verified by several 3-D numerical examples. Results show that the method is stable at the Courant stability limit for a regular FDTD grid, and has much higher accuracy than the conventional FDTD method.

  11. Lubrication Flows.

    ERIC Educational Resources Information Center

    Papanastasiou, Tasos C.

    1989-01-01

    Discusses fluid mechanics for undergraduates including the differential Navier-Stokes equations, dimensional analysis and simplified dimensionless numbers, control volume principles, the Reynolds lubrication equation for confined and free surface flows, capillary pressure, and simplified perturbation techniques. Provides a vertical dip coating…

  12. Instabilities in a cylindrical cavity heated from below with a free surface. II. Effect of a horizontal magnetic field.

    PubMed

    Touihri, R; El Gallaf, A; Henry, D; Ben Hadid, H

    2011-11-01

    The effect of a constant and uniform horizontal magnetic field on the flow in a cylindrical cavity heated from below, with a free surface at the top, is numerically investigated. The azimuthal modes, which usually trigger convection in a cylinder, are changed by the horizontal magnetic field to oriented modes, either parallel or perpendicular to the magnetic field direction. The corresponding primary thresholds increase with the Hartmann number Ha. This increase, however, depends on the structure of the modes and is the weakest for the parallel modes and the strongest for the perpendicular modes. The changes that affect the evolution of the primary thresholds with the aspect ratio for nonzero Ha are also emphasized. The nonlinear evolution of the convection with a horizontal magnetic field is presented through bifurcation diagrams for different values of the Prandtl number Pr. For Pr=1 and small values of Ha, the structuring effect of the horizontal magnetic field, which involves modifications of the flow structures and bifurcation points, is put into light. Results are finally shown for smaller Pr values corresponding to liquid metals.

  13. Non-aqueous carbon black suspensions for lithium-based redox flow batteries: rheology and simultaneous rheo-electrical behavior.

    PubMed

    Youssry, Mohamed; Madec, Lénaïc; Soudan, Patrick; Cerbelaud, Manuella; Guyomard, Dominique; Lestriez, Bernard

    2013-09-14

    We report on the rheological and electrical properties of non-aqueous carbon black (CB) suspensions at equilibrium and under steady shear flow. The smaller the primary particle size of carbon black is, the higher the magnitude of rheological parameters and the conductivity are. The electrical percolation threshold ranges seem to coincide with the strong gel rather than the weak gel rheological threshold ones. The simultaneous measurements of electrical properties under shear flow reveal the well-known breaking-and-reforming mechanism that characterises such complex fluids. The small shear rate breaks up the network into smaller agglomerates, which in turn transform into anisometric eroded ones at very high shear rates, recovering the network conductivity. The type of carbon black, its concentration range and the flow rate range are now precisely identified for optimizing the performance of a redox flow battery. A preliminary electrochemical study for a composite anolyte (CB/Li4Ti5O12) at different charge-discharge rates and thicknesses is shown.

  14. A stable finite difference method for the elastic wave equation on complex geometries with free surfaces

    SciTech Connect

    Appelo, D; Petersson, N A

    2007-12-17

    The isotropic elastic wave equation governs the propagation of seismic waves caused by earthquakes and other seismic events. It also governs the propagation of waves in solid material structures and devices, such as gas pipes, wave guides, railroad rails and disc brakes. In the vast majority of wave propagation problems arising in seismology and solid mechanics there are free surfaces. These free surfaces have, in general, complicated shapes and are rarely flat. Another feature, characterizing problems arising in these areas, is the strong heterogeneity of the media, in which the problems are posed. For example, on the characteristic length scales of seismological problems, the geological structures of the earth can be considered piecewise constant, leading to models where the values of the elastic properties are also piecewise constant. Large spatial contrasts are also found in solid mechanics devices composed of different materials welded together. The presence of curved free surfaces, together with the typical strong material heterogeneity, makes the design of stable, efficient and accurate numerical methods for the elastic wave equation challenging. Today, many different classes of numerical methods are used for the simulation of elastic waves. Early on, most of the methods were based on finite difference approximations of space and time derivatives of the equations in second order differential form (displacement formulation), see for example [1, 2]. The main problem with these early discretizations were their inability to approximate free surface boundary conditions in a stable and fully explicit manner, see e.g. [10, 11, 18, 20]. The instabilities of these early methods were especially bad for problems with materials with high ratios between the P-wave (C{sub p}) and S-wave (C{sub s}) velocities. For rectangular domains, a stable and explicit discretization of the free surface boundary conditions is presented in the paper [17] by Nilsson et al. In summary

  15. Chevron Defect at the Intersection of Grain Boundaries with Free Surfaces in Au

    NASA Astrophysics Data System (ADS)

    Radetic, T.; Lançon, F.; Dahmen, U.

    2002-08-01

    We have identified a new defect at the intersection between grain boundaries and surfaces in Au using atomic resolution transmission electron microscopy. At the junction line of 90° <110> tilt grain boundaries of (110)-(001) orientation with the free surface, a small segment of the grain boundary, about 1nm in length, dissociates into a triangular region with a chevronlike stacking disorder and a distorted hcp structure. The structure and stability of these defects are confirmed by atomistic simulations, and we point out the relationship with the one-dimensional incommensurate structure of the grain boundary.

  16. Nonlinear waves on the free surface of a dielectric liquid in an oblique electric field

    SciTech Connect

    Gashkov, M. A.; Zubarev, N. M. Kochurin, E. A.

    2015-09-15

    The nonlinear dynamics of the free surface of an ideal dielectric liquid that is exposed to an external oblique electric field has been studied theoretically. In the framework of the Hamiltonian formalism, a system of nonlinear integro-differential equations has been derived that describes the dynamics of nonlinear waves in the small-angle approximation. It is established that for a liquid with high dielectric permittivity, these equations have a solution in the form of plane waves of arbitrary shape that propagate without distortion in the direction of the horizontal component of the external field.

  17. Capillary waves in an inhomogeneous three-layer liquid with a free surface

    NASA Astrophysics Data System (ADS)

    Shiryaeva, S. O.; Grigor'ev, A. I.; Zav'yalov, D. A.

    2016-06-01

    In the domain of capillary waves, a bicubic dispersion relation is derived and analyzed for surface and internal capillary-gravitational waves in a three-layer liquid with a free surface. It is shown that the ratio of the internal wave amplitudes to the surface wave amplitudes is fairly large if the trivial condition of a "homogeneous liquid" is discarded. The amplitude ratio between the internal waves themselves (generated at different interfaces) may be both greater and smaller than unity depending on the physical parameters of the system. Specifically, it strongly depends on the densities of the layers and their thicknesses.

  18. Lithium in 2012

    USGS Publications Warehouse

    Jaskula, B.W.

    2013-01-01

    In 2012, estimated world lithium consumption was about 28 kt (31,000 st) of lithium contained in minerals and compounds, an 8 percent increase from that of 2011. Estimated U.S. consumption was about 2 kt (2,200 st) of contained lithium, the same as that of 2011. The United States was thought to rank fourth in consumption of lithium and remained the leading importer of lithium carbonate and the leading producer of value-added lithium materials. One company, Rockwood Lithium Inc., produced lithium compounds from domestic brine resources near Silver Peak, NV.

  19. Asymmetric material impact: Achieving free surfaces velocities nearly double that of the projectile

    SciTech Connect

    Aslam, Tariq; Dattelbaum, Dana; Gustavsen, Richard; Scharff, Robert; Byers, Mark

    2015-05-19

    Hypervelocity impact speeds are often limited by practical considerations in guns and explosive driven systems. In particular, for gas guns (both powder driven and light gas guns), there is the general trend that higher projectile speeds often come at the expense of smaller diameters, and thus less time for examining shock phenomena prior to two dimensional release waves affecting the observed quantities of interest. Similarly, explosive driven systems have their own set of limiting conditions due to limitations in explosive energy and size of devices required as engineering dimensions increase. The focus in this study is to present a methodology of obtaining free surface velocities well in excess of the projectile velocity. The key to this approach is in using a high impedance projectile that impacts a series of progressively lower impedance materials. The free surface velocity (if they were separated) of each of the progressively lower impedance materials would increase for each material. The theory behind this approach, as well as experimental results are presented.

  20. Asymmetric material impact: Achieving free surfaces velocities nearly double that of the projectile

    DOE PAGES

    Aslam, Tariq; Dattelbaum, Dana; Gustavsen, Richard; Scharff, Robert; Byers, Mark

    2015-05-19

    Hypervelocity impact speeds are often limited by practical considerations in guns and explosive driven systems. In particular, for gas guns (both powder driven and light gas guns), there is the general trend that higher projectile speeds often come at the expense of smaller diameters, and thus less time for examining shock phenomena prior to two dimensional release waves affecting the observed quantities of interest. Similarly, explosive driven systems have their own set of limiting conditions due to limitations in explosive energy and size of devices required as engineering dimensions increase. The focus in this study is to present a methodologymore » of obtaining free surface velocities well in excess of the projectile velocity. The key to this approach is in using a high impedance projectile that impacts a series of progressively lower impedance materials. The free surface velocity (if they were separated) of each of the progressively lower impedance materials would increase for each material. The theory behind this approach, as well as experimental results are presented.« less

  1. Simulation of bubble expansion and collapse in the vicinity of a free surface

    NASA Astrophysics Data System (ADS)

    Koukouvinis, P.; Gavaises, M.; Supponen, O.; Farhat, M.

    2016-05-01

    The present paper focuses on the numerical simulation of the interaction of laser-generated bubbles with a free surface, including comparison of the results with instances from high-speed videos of the experiment. The Volume Of Fluid method was employed for tracking liquid and gas phases while compressibility effects were introduced with appropriate equations of state for each phase. Initial conditions of the bubble pressure were estimated through the traditional Rayleigh Plesset equation. The simulated bubble expands in a non-spherically symmetric way due to the interference of the free surface, obtaining an oval shape at the maximum size. During collapse, a jet with mushroom cap is formed at the axis of symmetry with the same direction as the gravity vector, which splits the initial bubble to an agglomeration of toroidal structures. Overall, the simulation results are in agreement with the experimental images, both quantitatively and qualitatively, while pressure waves are predicted both during the expansion and the collapse of the bubble. Minor discrepancies in the jet velocity and collapse rate are found and are attributed to the thermodynamic closure of the gas inside the bubble.

  2. Spontaneous development of arcuate single-sided subduction in global 3-D mantle convection models with a free surface

    NASA Astrophysics Data System (ADS)

    Crameri, Fabio; Tackley, Paul

    2014-05-01

    The work presented aims at a better understanding of plate tectonics, a crucial dynamical feature within the global framework of mantle convection. Special focus is given to the interaction of subduction-related mantle flow and surface topography. Thereby, the application of a numerical model with two key functional requirements is essential: an evolution over a long time period to naturally model mantle flow and a physically correct topography calculation. The global mantle convection model presented in Crameri et al. (2012a) satisfies both of these requirements. First, it is efficiently calculated by the finite-volume code Stag-YY (e.g., Tackley 2008) using a multi-grid method on a fully staggered grid. Second, it applies the sticky-air method (Matsumoto and Tomoda 1983; Schmeling et al, 2008) and thus approximates a free surface when the sticky-air parameters are chosen carefully (Crameri et al., 2012b). This leads to dynamically self-consistent mantle convection with realistic, single-sided subduction. New insights are thus gained into the interplay of obliquely sinking plates, toroidal mantle flow and the arcuate shape of slabs and trenches. Numerous two-dimensional experiments provide optimal parameter setups that are applied to three-dimensional models in Cartesian and fully spherical geometries. Features observed and characterised in the latter experiments give important insight into the strongly variable behaviour of subduction zones along their strike. This includes (i) the spontaneous development of arcuate trench geometry, (ii) regional subduction polarity reversals and slab tearing, and the newly discovered features (iii) 'slab tunnelling' and (iv) 'back-slab spiral flow'. Overall, this study demonstrates the strong interaction between surface topography and mantle currents and highlights the variability of subduction zones and their individual segments. REFERENCES Crameri, F., P. J. Tackley, I. Meilick, T. V. Gerya, and B. J. P. Kaus (2012a), A free

  3. The lithium vapor box divertor

    NASA Astrophysics Data System (ADS)

    Goldston, R. J.; Myers, R.; Schwartz, J.

    2016-02-01

    It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m-2, implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. At the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma.

  4. Lithium-associated hyperthyroidism.

    PubMed

    Siyam, Fadi F; Deshmukh, Sanaa; Garcia-Touza, Mariana

    2013-08-01

    Goiters and hypothyroidism are well-known patient complications of the use of lithium for treatment of bipolar disease. However, the occurrence of lithium-induced hyperthyroidism is a more rare event. Many times, the condition can be confused with a flare of mania. Monitoring through serial biochemical measurement of thyroid function is critical in patients taking lithium. Hyperthyroidism induced by lithium is a condition that generally can be controlled medically without the patient having to discontinue lithium therapy, although in some circumstances, discontinuation of lithium therapy may be indicated. We report on a patient case of lithium-associated hyperthyroidism that resolved after discontinuation of the medication. PMID:23948626

  5. Step Free Surface Heteroepitaxy of 3C-SiC Layers on Patterned 4H/6H-SiC Mesas and Cantilevers

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.; Powell, J. Anthony; Trunek, Andrew J.; Spry, David J.

    2003-01-01

    Most SiC devices are implemented in homoepitaxial films grown on 4H/6H-SiC wafers with surfaces 3 degrees to 8 degrees off-axis from the (0001) basal plane. This approach has not prevented many substrate crystal defects from propagating into SiC epilayers, and does not permit the realization of SiC heteropolytype devices. This presentation describes recent advances in SiC epitaxial growth that begun to overcome the above shortcomings for arrays of mesas patterned into on-axis 4H/6H-SiC wafers. First, we demonstrated that atomic-scale surface steps can be completely eliminated from 4H/6H-SiC mesas via on-axis homoepitaxial step-flow growth, forming (0001) basal plane surfaces (up to 0.4 mm x 0.4 mm) for larger than previously thought possible. Step-free surface areas were then extended by growth fo thin lateral cantilevers from the mesa tops. These lateral cantilevers enabled substrate defects to be reduced and relocated in homoepitaxial films in a manner not possible with off-axis SiC growth. Finally, growth of vastly improved 3C-SiC heterofilms was achieved on 4H/6H-SiC mesas using the recently develop step-free surface heteroepitaxy process. These epitaxial growth developments should enable improved homojunction and heterojunction silicon carbide prototype devices.

  6. Dynamic simulation of free surfaces in capillaries with the finite element method

    NASA Astrophysics Data System (ADS)

    Trutschel, R.; Schellenberger, U.

    1998-02-01

    The mathematical formulation of the dynamics of free liquid surfaces including the effects of surface tension is governed by a non-linear system of elliptic differential equations. The major difficulty of getting unique closed solutions only in trivial cases is overcome by numerical methods. This paper considers transient simulations of liquid-gas menisci in vertical capillary tubes and gaps in the presence of gravity. Therefore the CFD code FIDAP 7.52 based on the Galerkin finite element method (FEM) is used. Calculations using the free surface model are presented for a variety of contact angles and cross-sections with experimental and theoretical verification. The liquid column oscillations are compared for numerical accuracy with a mechanical mathematical model, and the sensitivity with respect to the node density is investigated. The efficiency of the numerical treatment of geometric non-trivial problems is demonstrated by a prismatic capillary. Present restrictions limiting efficient transient simulations with irregularly shaped calculational domains are stated.

  7. Pb-free surface-finishing on electronic components' terminals for Pb-free soldering assembly

    SciTech Connect

    Tanaka, Hitoshi; Tanimoto, Morimasa; Matsuda, Akira; Uno, Takeo; Kurihara, Masaaki; Shiga, Shoji

    1999-11-01

    Pb-free solderable surface finishing is essential to implement Pb-free solder assembly in order to meet with the growing demand of environmental consciousness to eliminate Pb from electronic products. Two types of widely applicable Pb-free surface finishing technologies are developed. One is the multilayer-system including Pd with Ni undercoat. Heat-resistance of Pd enables whole-surface-plating on to leadframe before IC-assembling process. The other is the double-layer-system with low-melting-point-materials, for example, thicker Sn underlayer and thinner Sn-Bi alloy overlayer, dilutes Sn-Bi alloy's defects of harmful reactivity along with substrate metal and mechanical brittleness with keeping its advantages of solder-wettability and no whisker.

  8. A communication-avoiding implicit-explicit method for a free-surface ocean model

    NASA Astrophysics Data System (ADS)

    Newman, Christopher; Womeldorff, Geoffrey; Knoll, Dana A.; Chacón, Luis

    2016-01-01

    We examine a nonlinear elimination method for the free-surface ocean equations based on barotropic-baroclinic decomposition. The two dimensional scalar continuity equation is treated implicitly with a preconditioned Jacobian-free Newton-Krylov method (JFNK). The remaining three dimensional equations are subcycled explicitly within the JFNK residual evaluation with a method known as nonlinear elimination. In this approach, the memory footprint of the underlying Krylov vector is greatly reduced over that required by fully coupled implicit methods. The method is second-order accurate and scales algorithmically, with allowed timesteps much larger than fully explicit methods. Moreover, the hierarchical nature of the algorithm lends itself readily to emerging architectures. In particular, we introduce a communication staging strategy for the three dimensional explicit system that greatly reduces the communication costs of the algorithm and provides a key advantage as communication costs continue to dominate relative to floating point costs in emerging architectures.

  9. Evaporation model for beam based additive manufacturing using free surface lattice Boltzmann methods

    NASA Astrophysics Data System (ADS)

    Klassen, Alexander; Scharowsky, Thorsten; Körner, Carolin

    2014-07-01

    Evaporation plays an important role in many technical applications including beam-based additive manufacturing processes, such as selective electron beam or selective laser melting (SEBM/SLM). In this paper, we describe an evaporation model which we employ within the framework of a two-dimensional free surface lattice Boltzmann method. With this method, we solve the hydrodynamics as well as thermodynamics of the molten material taking into account the mass and energy losses due to evaporation and the recoil pressure acting on the melt pool. Validation of the numerical model is performed by measuring maximum melt depths and evaporative losses in samples of pure titanium and Ti-6Al-4V molten by an electron beam. Finally, the model is applied to create processing maps for an SEBM process. The results predict that the penetration depth of the electron beam, which is a function of the acceleration voltage, has a significant influence on evaporation effects.

  10. Free-surface temperature measurement of shock-loaded tin using ultrafast infrared pyrometry

    NASA Astrophysics Data System (ADS)

    Mondot, Michel; Remiot, Christian

    1991-11-01

    The main problem regarding free surface temperature measurement by infrared pyrometry is the lack of emissivity data of shocked materials. Moreover, the short rise time in an hydrodynamic experiment requires particular detectors and experimental measurement technique. This paper describes a three channel pyrometer adapted to the study of shocked tin sample melted in release. The radiative infrared emission is collected by ZnSe lens and carried from the firing chamber to the pyrometer by fluoride glass optical fiber. In order to deduce the temperature from the electrical signals amplified before recording on a numerical oscilloscope, we use different narrow filters associated with a previous static calibration of the detectors by means of a continuously heated black body. The spectral integration of Planck's formula and the comparison between the static calibration with the black body and the dynamic signals give, for each experiment, three temperature-emissivity couples in agreement with Planck's theory. The originality of this measurement technique is the use of a 15 meter infrared optical triple core fiber for transporting the radiation from the target to the detectors, which simultaneously permits the measurement of three temperature-emissivity couples in the case of very small and hermetic experimental set-up. The main characteristics of this pyrometer are: a rise time of about 20 nanoseconds; an analysis area with a diameter smaller than 5 millimeters; continuous free surface temperature measurement during more than 5 microseconds; and the study of the wavelengths between 2 and 5 micrometers. Experiments have been achieved with optical polished tin samples. The abacus voltages, temperature, and emissivity versus time for a 45 GPa shock pressure is discussed.

  11. Fluid flow over arbitrary bottom topography in a channel

    NASA Astrophysics Data System (ADS)

    Panda, Srikumar

    2016-05-01

    In this paper, two-dimensional free surface potential flow over an arbitrary bottom in a channel is considered to analyze the behavior of the free surface profile using linear theory. It is assumed that the fluid is inviscid, incompressible and flow is irrotational. Perturbation analysis in conjunction with Fourier transform technique is employed to determine the first order corrections of some important physical quantities such as free surface profile, velocity potential, etc. From the practical point of view, one arbitrary bottom topography is considered to determine the free surface profile since the free surface profile depends on the bottom topography. It is found that the free surface profile is oscillatory in nature, representing a wave propagating downstream and no wave upstream.

  12. Stabilization of tokamak plasma by lithium streams

    SciTech Connect

    L.E. Zakharov

    2000-08-07

    The stabilization theory of free-boundary magnetohydrodynamic instabilities in tokamaks by liquid lithium streams driven by magnetic propulsion is formulated. While the conventional, wall-locked, resistive wall mode can be well suppressed by the flow, a new, stream-locked mode determines the limits of the flow stabilization.

  13. Thermal migration of deuterium implanted in graphite: Influence of free surface proximity and structure

    NASA Astrophysics Data System (ADS)

    Le Guillou, M.; Moncoffre, N.; Toulhoat, N.; Pipon, Y.; Ammar, M. R.; Rouzaud, J. N.; Deldicque, D.

    2016-03-01

    This paper is a contribution to the study of the behavior of activation products produced in irradiated nuclear graphite, graphite being the moderator of the first French generation of CO2 cooled nuclear fission reactors. This paper is focused on the thermal release of Tritium, a major contributor to the initial activity, taking into account the role of the free surfaces (open pores and graphite surface). Two kinds of graphite were compared. On one hand, Highly Oriented Pyrolitic Graphite (HOPG), a model well graphitized graphite, and on the other hand, SLA2, a porous less graphitized nuclear graphite. Deuterium ion implantation at three different energies 70, 200 and 390 keV allows simulating the presence of Tritium at three different depths, corresponding respectively to projected ranges Rp of 0.75, 1.7 and 3.2 μm. The D isotopic tracing is performed thanks to the D(3He,p)4He nuclear reaction. The graphite structure is studied by Raman microspectrometry. Thermal annealing is performed in the temperature range 200-1200 °C up to 300 h annealing time. As observed in a previous study, the results show that the D release occurs according to three kinetic regimes: a rapid permeation through open pores, a transient regime corresponding to detrapping and diffusion of D located at low energy sites correlated to the edges of crystallites and finally a saturation regime attributed to detrapping of interstitial D located at high energy sites inside the crystallites. Below 600 °C, D release is negligible whatever the implantation depth and the graphite type. The present paper clearly puts forward that above 600 °C, the D release decreases at deeper implantation depths and strongly depends on the graphite structure. In HOPG where high energy sites are more abundant, the D release is less dependent on the surface proximity compared to SLA2. In SLA2, in which the low energy sites prevail, the D release curves are clearly shifted towards lower temperatures when D is located

  14. Molten salt lithium cells

    DOEpatents

    Raistrick, I.D.; Poris, J.; Huggins, R.A.

    1980-07-18

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400 to 500/sup 0/C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell which may be operated at temperatures between about 100 to 170/sup 0/C. The cell is comprised of an electrolyte, which preferably includes lithium nitrate, and a lithium or lithium alloy electrode.

  15. Molten salt lithium cells

    DOEpatents

    Raistrick, Ian D.; Poris, Jaime; Huggins, Robert A.

    1983-01-01

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell (10) which may be operated at temperatures between about 100.degree.-170.degree. C. Cell (10) comprises an electrolyte (16), which preferably includes lithium nitrate, and a lithium or lithium alloy electrode (12).

  16. Molten salt lithium cells

    DOEpatents

    Raistrick, Ian D.; Poris, Jaime; Huggins, Robert A.

    1982-02-09

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell (10) which may be operated at temperatures between about 100.degree.-170.degree. C. Cell (10) comprises an electrolyte (16), which preferably includes lithium nitrate, and a lithium or lithium alloy electrode (12).

  17. Tuning the Electron Gas at an Oxide Heterointerface via Free Surface Charges

    SciTech Connect

    Bell, Christopher

    2011-08-11

    Oxide heterointerfaces are emerging as one of the most exciting materials systems in condensed matter science. One remarkable example is the LaAlO{sub 3}/SrTiO{sub 3} (LAO/STO) interface, a model system in which a highly mobile electron gas forms between two band insulators, exhibiting two dimensional superconductivity and unusual magnetotransport properties. An ideal tool to tune such an electron gas is the electrostatic field effect. In principle, the electrostatic field can be generated by bound charges due to polarization (as in the normal and ferroelectric field effects) or by adding excess free charge. In previous studies, a large modulation of the carrier density and mobility of the LAO/STO interface has been achieved using the normal field effect. However, little attention has been paid to the field effect generated by free charges. This issue is scarcely addressed, even in conventional semiconductor devices, since the free charges are typically not stable. Here, we demonstrate an unambiguous tuning of the LAO/STO interface conductivity via free surface charges written using conducting atomic force microscopy (AFM). The modulation of the carrier density was found to be reversible, nonvolatile and surprisingly large, {approx}3 x 10{sup 13} cm{sup -2}, comparable to the maximum modulation by the normal field effect. Our finding reveal the efficiency of free charges in controlling the conductivity of this oxide interface, and suggest that this technique may be extended more generally to other oxide systems.

  18. An analytical and numerical study of the nonlinear reflection at a stress-free surface

    NASA Astrophysics Data System (ADS)

    Romer, Anne; Kim, Jin-Yeon; Jacobs, Laurence J.

    2015-03-01

    Implementation of the ultrasonic second harmonic generation has typically been restricted to simple setups such as through-transmission or Rayleigh surface waves. Recent research has evaluated the second harmonic waves generation in P- and SV- waves reflected from a stress-free surface to enable the single-sided interrogation of a specimen. This research considers the second harmonic generation in an aluminum specimen, which is analytically evaluated using an approach based on a perturbation method. Here, the model is chosen to mimic an experimental setup where the longitudinal wave is generated at oblique angle using a wedge transducer. Due to the mode conversion at the interface of the wedge and the specimen, it is necessary to evaluate longitudinal and shear waves, determining all second harmonic waves generated in the bulk and at the stress-free boundary. The theoretically developed model is then implemented in a commercial finite element code, COMSOL, using increasing fundamental wave amplitudes for different values of third order elastic constants. The results of this computational model verify the analytical approach and the proposed measurement setup, taking into account assumptions and approximations of the solution procedure. Furthermore, the computational model is used to draw important conclusions relevant to the experimental setup, including the need to avoid interaction with diffracted waves.

  19. An analytical and numerical study of the nonlinear reflection at a stress-free surface

    SciTech Connect

    Romer, Anne Kim, Jin-Yeon; Jacobs, Laurence J.

    2015-03-31

    Implementation of the ultrasonic second harmonic generation has typically been restricted to simple setups such as through-transmission or Rayleigh surface waves. Recent research has evaluated the second harmonic waves generation in P- and SV- waves reflected from a stress-free surface to enable the single-sided interrogation of a specimen. This research considers the second harmonic generation in an aluminum specimen, which is analytically evaluated using an approach based on a perturbation method. Here, the model is chosen to mimic an experimental setup where the longitudinal wave is generated at oblique angle using a wedge transducer. Due to the mode conversion at the interface of the wedge and the specimen, it is necessary to evaluate longitudinal and shear waves, determining all second harmonic waves generated in the bulk and at the stress-free boundary. The theoretically developed model is then implemented in a commercial finite element code, COMSOL, using increasing fundamental wave amplitudes for different values of third order elastic constants. The results of this computational model verify the analytical approach and the proposed measurement setup, taking into account assumptions and approximations of the solution procedure. Furthermore, the computational model is used to draw important conclusions relevant to the experimental setup, including the need to avoid interaction with diffracted waves.

  20. Experimental investigation of free surface vortices and definition of gas entrainment occurrence maps

    NASA Astrophysics Data System (ADS)

    Caruso, G.; Cristofano, L.; Nobili, M.; Vitale Di Maio, D.

    2014-04-01

    For the future development of Generation IV nuclear reactors, both safety and economic targets have to be achieved. In order to increase, at the same time, the power density generation and the safety features, a huge R&D effort is still required. Referring especially to Liquid Metal Cooled Fast Reactors, much attention is placed on Gas Entrainment (GE) phenomena, which could cause unlikely positive reactivity insertion accident. The GETS experimental facility (Gas Entrainment Test Section), especially aimed at studying the free surface vortices occurrence, has been built in the thermal-hydraulics laboratory of the DIAEE. The main purpose of this facility is to identify the most important parameters affecting the whirlpools formation and evolution. Experimental tests and preliminary observations have been performed. Different vortex behaviours related to different experimental conditions have been identified and presented in the present paper. 2D occurrence maps as function of different dimensionless groups (Reynolds, Froude and Weber numbers and H* = H/d ratio) have been defined. In the present paper, the results of a first experimental campaign, carried out with tap water, are discussed.

  1. Eigenvalue Problems for Vibrating Structures Coupled with Quiescent Fluids with Free Surface

    NASA Astrophysics Data System (ADS)

    AMABILI, M.

    2000-03-01

    Vibrations of plates, shells and plate-shell systems coupled with sloshing, quiescent and inviscid fluid have been advantageously studied by inserting the sloshing condition into the eigenvalue problem. Here a formulation of this particular eigenvalue problem for symmetric matrices is obtained. In fact, in the previous studies, this technique has given eigenvalue problems for non-symmetric matrices for which the problem of the existence of complex eigenvalues arises. The present analysis deals with compressible and incompressible fluids and the discretization of the system is obtained by using the Rayleigh-Ritz method. The Rayleigh quotient of the system is manipulated to obtain expressions suitable for symmetric formulations of the eigenvalue problem. In particular, the Rayleigh quotient is transformed into a simpler expression where the potential energies of the compressible fluid and free surface waves do not appear. The method is applied to a vertical, simply supported, circular cylindrical shell partially filled by an incompressible sloshing liquid. A case with large interaction between sloshing and bulging modes is considered and interesting phenomena are observed.

  2. Hydroelastic vibration of circular plates immersed in a liquid-filled container with free surface

    NASA Astrophysics Data System (ADS)

    Askari, Ehsan; Jeong, Kyeong-Hoon; Amabili, Marco

    2013-06-01

    In the present study, a theoretical method is developed to investigate free vibrations of circular plates immersed in fluids and a series of experimental tests are presented to validate the model. The coupled governing equations of both hydroelastic vibration of the plate and liquid sloshing are solved by a semi-analytical procedure, simultaneously. The effect of the plate, used as a baffle, on suppression free surface waves is also considered. Plates with two different boundary conditions, free-edge and clamped edge, are studied. The fluid domain is non-convex because of the presence of the plate, which introduces a singularity in the formulation of the fluid velocity potential. Both the least square and Galerkin methods are applied to determine the unknown coefficients in the velocity potential. Natural frequencies and mode shapes are obtained using the Rayleigh-Ritz method, taking fluid-structure interaction into account. The present approach is validated by comparison to results of modal test on two different steel plates with the free edge and submerged in water, as well as comparison to those of a commercial finite element code. The results obtained from the present method agree with those obtained from modal test and the finite element analysis.

  3. High bandwidth linear viscoelastic properties of complex fluids from the measurement of their free surface fluctuations

    NASA Astrophysics Data System (ADS)

    Pottier, Basile; Talini, Laurence; Frétigny, Christian

    2012-02-01

    We present a new optical method to measure the linear viscoelastic properties of materials, ranging from complex fluids to soft solids, within a large frequency range (about 0.1--10^4 Hz). The surface fluctuation specular reflection technique is based on the measurement of the thermal fluctuations of the free surfaces of materials at which a laser beam is specularly reflected. The propagation of the thermal surface waves depends on the surface tension, density, and complex viscoelastic modulus of the material. For known surface tension and density, we show that the frequency dependent elastic and loss moduli can be deduced from the fluctuation spectrum. Using a viscoelastic solid (a cross-linked PDMS), which linear viscoelastic properties are known in a large frequency range from rheometric measurements and the time--temperature superposition principle, we show that there is a good agreement between the rheological characterization provided by rheometric and fluctuation measurements. We also present measurements conducted with complex fluids that are supramolecular polymer solutions. The agreement with other low frequency and high frequency rheological measurements is again very good, and we discuss the sensitivity of the technique to surface viscoelasticity.

  4. Lithium Circuit Test Section Design and Fabrication

    NASA Technical Reports Server (NTRS)

    Godfroy, Thomas; Garber, Anne

    2006-01-01

    The Early Flight Fission - Test Facilities (EFF-TF) team has designed and built an actively pumped lithium flow circuit. Modifications were made to a circuit originally designed for NaK to enable the use of lithium that included application specific instrumentation and hardware. Component scale freeze/thaw tests were conducted to both gain experience with handling and behavior of lithium in solid and liquid form and to supply anchor data for a Generalized Fluid System Simulation Program (GFSSP) model that was modified to include the physics for freeze/thaw transitions. Void formation was investigated. The basic circuit components include: reactor segment, lithium to gas heat exchanger, electromagnetic (EM) liquid metal pump, load/drain reservoir, expansion reservoir, instrumentation, and trace heaters. This paper will discuss the overall system design and build and the component testing findings.

  5. Lithium Circuit Test Section Design and Fabrication

    NASA Astrophysics Data System (ADS)

    Godfroy, Thomas; Garber, Anne; Martin, James

    2006-01-01

    The Early Flight Fission - Test Facilities (EFF-TF) team has designed and built an actively pumped lithium flow circuit. Modifications were made to a circuit originally designed for NaK to enable the use of lithium that included application specific instrumentation and hardware. Component scale freeze/thaw tests were conducted to both gain experience with handling and behavior of lithium in solid and liquid form and to supply anchor data for a Generalized Fluid System Simulation Program (GFSSP) model that was modified to include the physics for freeze/thaw transitions. Void formation was investigated. The basic circuit components include: reactor segment, lithium to gas heat exchanger, electromagnetic (EM) liquid metal pump, load/drain reservoir, expansion reservoir, instrumentation, and trace heaters. This paper discusses the overall system design and build and the component testing findings.

  6. Lithium Circuit Test Section Design and Fabrication

    SciTech Connect

    Godfroy, Thomas; Garber, Anne; Martin, James

    2006-01-20

    The Early Flight Fission -- Test Facilities (EFF-TF) team has designed and built an actively pumped lithium flow circuit. Modifications were made to a circuit originally designed for NaK to enable the use of lithium that included application specific instrumentation and hardware. Component scale freeze/thaw tests were conducted to both gain experience with handling and behavior of lithium in solid and liquid form and to supply anchor data for a Generalized Fluid System Simulation Program (GFSSP) model that was modified to include the physics for freeze/thaw transitions. Void formation was investigated. The basic circuit components include: reactor segment, lithium to gas heat exchanger, electromagnetic (EM) liquid metal pump, load/drain reservoir, expansion reservoir, instrumentation, and trace heaters. This paper discusses the overall system design and build and the component testing findings.

  7. Lithium Battery Diaper Ulceration.

    PubMed

    Maridet, Claire; Taïeb, Alain

    2016-01-01

    We report a case of lithium battery diaper ulceration in a 16-month-old girl. Gastrointestinal and ear, nose, and throat lesions after lithium battery ingestion have been reported, but skin involvement has not been reported to our knowledge.

  8. Experimental assessment of blade tip immersion depth from free surface on average power and thrust coefficients of marine current turbine

    NASA Astrophysics Data System (ADS)

    Lust, Ethan; Flack, Karen; Luznik, Luksa

    2014-11-01

    Results from an experimental study on the effects of marine current turbine immersion depth from the free surface are presented. Measurements are performed with a 1/25 scale (diameter D = 0.8m) two bladed horizontal axis turbine towed in the large towing tank at the U.S. Naval Academy. Thrust and torque are measured using a dynamometer, mounted in line with the turbine shaft. Shaft rotation speed and blade position are measured using a shaft position indexing system. The tip speed ratio (TSR) is adjusted using a hysteresis brake which is attached to the output shaft. Two optical wave height sensors are used to measure the free surface elevation. The turbine is towed at 1.68 m/s, resulting in a 70% chord based Rec = 4 × 105. An Acoustic Doppler Velocimeter (ADV) is installed one turbine diameter upstream of the turbine rotation plane to characterize the inflow turbulence. Measurements are obtained at four relative blade tip immersion depths of z/D = 0.5, 0.4, 0.3, and 0.2 at a TSR value of 7 to identify the depth where free surface effects impact overall turbine performance. The overall average power and thrust coefficient are presented and compared to previously conducted baseline tests. The influence of wake expansion blockage on the turbine performance due to presence of the free surface at these immersion depths will also be discussed.

  9. Free surface fluid behavior in two-dimensional container with arbitrary configuration - Computer simulation and experiment by using drop tower

    NASA Astrophysics Data System (ADS)

    Ohnishi, Mitsuru; Ogiwara, Sachio; Yoshihara, Shoichi; Azuma, Hisao

    1989-10-01

    A new and powerful program based on the SOLA-VOF code is presented which is designed to study the behavior of fluids with free surfaces under reduced gravity. The capability of the program is demonstrated using a drop tower for fluid transportation and formation of spherical voids. Good agreement is found between the results and computational findings.

  10. Critical Velocities in Open Capillary Flow

    NASA Technical Reports Server (NTRS)

    Dreyer, Michael; Langbein, Dieter; Rath, Hans J.

    1996-01-01

    This paper describes the proposed research program on open capillary flow and the preliminary work performed theoretically and in drop tower experiments. The work focuses on the fundamental physical understanding of the flow through capillary bound geometries, where the circumference of the cross section of the flow path contains free surfaces. Examples for such a flow configuration are capillary vanes in surface tension tanks, flow along edges and corners and flow through liquid bridges. The geometries may be classified by their cross section areas, wetted circumferences and the radii of curvature of the free surfaces. In the streaming float zone the flow path is bound by a free surface only. The ribbon vane is a model for vane types used in surface tension tanks, where a structure in proximity to the tank wall forms a capillary gap. A groove is used in heat pipes for the transportation of the condensed working fluid to the heat source and a wedge may occur in a spaceborne experiment where fluid has to be transported by the means of surface tension. The research objectives are the determination of the maximum volume flux, the observation of the free surfaces and the liquid flow inside the flow path as well as the evaluation of the limiting capillary wave speed. The restriction of the maximum volume flux is due to convective forces (flow velocity exceeding the capillary wave speed) and/or viscous forces, i.e. the viscous head loss along the flow path must be compensated by the capillary pressure due to the curved free surface. Exceeding the maximum volume flux leads to the choking of the flow path, thus the free surface collapses and.gas ingestion occurs at the outlet. The means are ground-based experimental work with plateau tanks and in a drop tower, a sounding rocket flight, and theoretical analysis with integral balances as well as full three dimensional CFD solutions for flow with free surfaces.

  11. Lithium use in batteries

    USGS Publications Warehouse

    Goonan, Thomas G.

    2012-01-01

    Lithium has a number of uses but one of the most valuable is as a component of high energy-density rechargeable lithium-ion batteries. Because of concerns over carbon dioxide footprint and increasing hydrocarbon fuel cost (reduced supply), lithium may become even more important in large batteries for powering all-electric and hybrid vehicles. It would take 1.4 to 3.0 kilograms of lithium equivalent (7.5 to 16.0 kilograms of lithium carbonate) to support a 40-mile trip in an electric vehicle before requiring recharge. This could create a large demand for lithium. Estimates of future lithium demand vary, based on numerous variables. Some of those variables include the potential for recycling, widespread public acceptance of electric vehicles, or the possibility of incentives for converting to lithium-ion-powered engines. Increased electric usage could cause electricity prices to increase. Because of reduced demand, hydrocarbon fuel prices would likely decrease, making hydrocarbon fuel more desirable. In 2009, 13 percent of worldwide lithium reserves, expressed in terms of contained lithium, were reported to be within hard rock mineral deposits, and 87 percent, within brine deposits. Most of the lithium recovered from brine came from Chile, with smaller amounts from China, Argentina, and the United States. Chile also has lithium mineral reserves, as does Australia. Another source of lithium is from recycled batteries. When lithium-ion batteries begin to power vehicles, it is expected that battery recycling rates will increase because vehicle battery recycling systems can be used to produce new lithium-ion batteries.

  12. Rechargeable lithium cell

    NASA Astrophysics Data System (ADS)

    Salomon, M.; Plichta, E. J.

    1984-09-01

    The general object of this invention is to provide an improved rechargeable lithium cell. A more specific object of the invention is to provide a rechargeable lithium cell having an improved low temperature performance and rate capability. It has now been found that the aformentioned objects can be attained using lithium as the anode, a solution of a lithium salt such as LiF6 or LiAlC14 in a mixed organic solvent as the electrolyte and a lithium intercalating cathode.

  13. The synergetic effect of lithium polysulfide and lithium nitrate to prevent lithium dendrite growth

    NASA Astrophysics Data System (ADS)

    Li, Weiyang; Yao, Hongbin; Yan, Kai; Zheng, Guangyuan; Liang, Zheng; Chiang, Yet-Ming; Cui, Yi

    2015-06-01

    Lithium metal has shown great promise as an anode material for high-energy storage systems, owing to its high theoretical specific capacity and low negative electrochemical potential. Unfortunately, uncontrolled dendritic and mossy lithium growth, as well as electrolyte decomposition inherent in lithium metal-based batteries, cause safety issues and low Coulombic efficiency. Here we demonstrate that the growth of lithium dendrites can be suppressed by exploiting the reaction between lithium and lithium polysulfide, which has long been considered as a critical flaw in lithium-sulfur batteries. We show that a stable and uniform solid electrolyte interphase layer is formed due to a synergetic effect of both lithium polysulfide and lithium nitrate as additives in ether-based electrolyte, preventing dendrite growth and minimizing electrolyte decomposition. Our findings allow for re-evaluation of the reactions regarding lithium polysulfide, lithium nitrate and lithium metal, and provide insights into solving the problems associated with lithium metal anodes.

  14. The synergetic effect of lithium polysulfide and lithium nitrate to prevent lithium dendrite growth.

    PubMed

    Li, Weiyang; Yao, Hongbin; Yan, Kai; Zheng, Guangyuan; Liang, Zheng; Chiang, Yet-Ming; Cui, Yi

    2015-01-01

    Lithium metal has shown great promise as an anode material for high-energy storage systems, owing to its high theoretical specific capacity and low negative electrochemical potential. Unfortunately, uncontrolled dendritic and mossy lithium growth, as well as electrolyte decomposition inherent in lithium metal-based batteries, cause safety issues and low Coulombic efficiency. Here we demonstrate that the growth of lithium dendrites can be suppressed by exploiting the reaction between lithium and lithium polysulfide, which has long been considered as a critical flaw in lithium-sulfur batteries. We show that a stable and uniform solid electrolyte interphase layer is formed due to a synergetic effect of both lithium polysulfide and lithium nitrate as additives in ether-based electrolyte, preventing dendrite growth and minimizing electrolyte decomposition. Our findings allow for re-evaluation of the reactions regarding lithium polysulfide, lithium nitrate and lithium metal, and provide insights into solving the problems associated with lithium metal anodes. PMID:26081242

  15. The synergetic effect of lithium polysulfide and lithium nitrate to prevent lithium dendrite growth.

    PubMed

    Li, Weiyang; Yao, Hongbin; Yan, Kai; Zheng, Guangyuan; Liang, Zheng; Chiang, Yet-Ming; Cui, Yi

    2015-06-17

    Lithium metal has shown great promise as an anode material for high-energy storage systems, owing to its high theoretical specific capacity and low negative electrochemical potential. Unfortunately, uncontrolled dendritic and mossy lithium growth, as well as electrolyte decomposition inherent in lithium metal-based batteries, cause safety issues and low Coulombic efficiency. Here we demonstrate that the growth of lithium dendrites can be suppressed by exploiting the reaction between lithium and lithium polysulfide, which has long been considered as a critical flaw in lithium-sulfur batteries. We show that a stable and uniform solid electrolyte interphase layer is formed due to a synergetic effect of both lithium polysulfide and lithium nitrate as additives in ether-based electrolyte, preventing dendrite growth and minimizing electrolyte decomposition. Our findings allow for re-evaluation of the reactions regarding lithium polysulfide, lithium nitrate and lithium metal, and provide insights into solving the problems associated with lithium metal anodes.

  16. Free Surface Command Layer for Photoswitchable Out-of-Plane Alignment Control in Liquid Crystalline Polymer Films.

    PubMed

    Nakai, Takashi; Tanaka, Daisuke; Hara, Mitsuo; Nagano, Shusaku; Seki, Takahiro

    2016-01-26

    To date, reversible alignment controls of liquid crystalline materials have widely been achieved by photoreactive layers on solid substrates. In contrast, this work demonstrates the reversible out-of-plane photocontrols of liquid crystalline polymer films by using a photoresponsive skin layer existing at the free surface. A polymethacrylate containing a cyanobiphenyl side-chain mesogen adopts the planar orientation. Upon blending a small amount of azobenzene-containing side-chain polymer followed by successive annealing, segregation of the azobenzene polymer at the free surface occurs and induces a planar to homeotropic orientation transition of cyanobiphenyl mesogens underneath. By irradiation with UV light, the mesogen orientation turns into the planar orientation. The orientation reverts to the homeotropic state upon visible light irradiation or thermally, and such cyclic processes can be repeated many times. On the basis of this principle, erasable optical patterning is performed by irradiating UV light through a photomask. PMID:26734930

  17. Free Surface Command Layer for Photoswitchable Out-of-Plane Alignment Control in Liquid Crystalline Polymer Films.

    PubMed

    Nakai, Takashi; Tanaka, Daisuke; Hara, Mitsuo; Nagano, Shusaku; Seki, Takahiro

    2016-01-26

    To date, reversible alignment controls of liquid crystalline materials have widely been achieved by photoreactive layers on solid substrates. In contrast, this work demonstrates the reversible out-of-plane photocontrols of liquid crystalline polymer films by using a photoresponsive skin layer existing at the free surface. A polymethacrylate containing a cyanobiphenyl side-chain mesogen adopts the planar orientation. Upon blending a small amount of azobenzene-containing side-chain polymer followed by successive annealing, segregation of the azobenzene polymer at the free surface occurs and induces a planar to homeotropic orientation transition of cyanobiphenyl mesogens underneath. By irradiation with UV light, the mesogen orientation turns into the planar orientation. The orientation reverts to the homeotropic state upon visible light irradiation or thermally, and such cyclic processes can be repeated many times. On the basis of this principle, erasable optical patterning is performed by irradiating UV light through a photomask.

  18. Method of recycling lithium borate to lithium borohydride through diborane

    DOEpatents

    Filby, Evan E.

    1976-01-01

    This invention provides a method for the recycling of lithium borate to lithium borohydride which can be reacted with water to generate hydrogen for utilization as a fuel. The lithium borate by-product of the hydrogen generation reaction is reacted with hydrogen chloride and water to produce boric acid and lithium chloride. The boric acid and lithium chloride are converted to lithium borohydride through a diborane intermediate to complete the recycle scheme.

  19. Results from the CDX-U Lithium Wall and NSTX Lithium Pallet Injection and Evaporation Experiments

    SciTech Connect

    Majeski, R; Kugel, H; Bell, M; Bell, R; Beiersdorfer, P; Bush, C; Doerner, R; Gates, D; Gray, T; Kaita, R; LeBlanc, B; Maingi, R; Mansfield, D; Menard, J; Mueller, D; Paul, S; Raman, R; Roquemore, A; Skinner, C; Sabbagh, S; Souskhanovskii, V; Spaleta, J; Stevenson, T; Timberlake, J; Zakharov, L

    2006-10-05

    significant increases in electron and ion temperature, neutron rate, confinement time, and edge flow velocity, and reductions in H-mode ELM frequency. For several days of operation after lithium coating, the ratio of oxygen to carbon emission was lower than with boronization.

  20. Comparative study of the free-surface boundary condition in two-dimensional finite-difference elastic wave field simulation

    NASA Astrophysics Data System (ADS)

    Lan, Haiqiang; Zhang, Zhongjie

    2011-06-01

    The finite-difference (FD) method is a powerful tool in seismic wave field modelling for understanding seismic wave propagation in the Earth's interior and interpreting the real seismic data. The accuracy of FD modelling partly depends on the implementation of the free-surface (i.e. traction-free) condition. In the past 40 years, at least six kinds of free-surface boundary condition approximate schemes (such as one-sided, centred finite-difference, composed, new composed, implicit and boundary-modified approximations) have been developed in FD second-order elastodynamic simulation. Herein we simulate seismic wave fields in homogeneous and lateral heterogeneous models using these free-surface boundary condition approximate schemes and evaluate their stability and applicability by comparing with corresponding analytical solutions, and then quantitatively evaluate the accuracies of different approximate schemes from the misfit of the amplitude and phase between the numerical and analytical results. Our results confirm that the composed scheme becomes unstable for the Vs/Vp ratio less than 0.57, and suggest that (1) the one-sided scheme is only accurate to first order and therefore introduces serious errors for the shorter wavelengths, other schemes are all of second-order precision; (2) the new composed, implicit and boundary-modified schemes are stable even when the Vs/Vp ratio is less than 0.2; (3) the implicit and boundary-modified schemes are able to deal with laterally varying (heterogeneous) free surface; (4) in the corresponding stability range, the one-sided scheme shows remarkable errors in both phase and amplitude compared to analytical solution (which means larger errors in travel-time and reflection strength), the other five approximate schemes show better performance in travel-time (phase) than strength (amplitude).

  1. Modeling of Oblique Penetration into Geologic Targets Using Cavity Expansion Penetrator Loading with Target free-Surface Effects

    SciTech Connect

    Jung, Joe; Longcope, Donald B.; Tabbara, Mazen R.

    1999-06-01

    A procedure has been developed to represent the loading on a penetrator and its motion during oblique penetration into geologic media. The penetrator is modeled with the explicit dynamics, finite element computer program PRONTO 3D and the coupled pressure on the penetrator is given in a new loading option based on a separate cavity expansion (CE) solution that accounts for the pressure reduction from a nearby target free surface. The free-surface influence distance is selected in a predictive manner by considering the pressure to expand a spherical cavity in a finite radius sphere of the target material. The CE/PRONTO 3D procedure allows a detailed description of the penetrator for predicting shock environments or structural failure during the entire penetra- tion event and is sufficiently rapid to be used in design optimization. It has been evaluated by comparing its results with data from two field tests of a full-scale penetrator into frozen soil at an impact angles of 49.6 and 52.5 degrees from the horizontal. The measured penetrator rotations were 24 and 22 degrees, respectively. In the simulation, the rotation was 21 degrees and predom- inately resulted from the pressure reduction of the free surface. Good agreement was also found for the penetration depth and axial and lateral acceleration at two locations in the penetrator.

  2. Modeling of Oblique Penetration into Geologic Targets Using Cavity Expansion Penetrator Loading with Target free-Surface Effects

    SciTech Connect

    Jung, Joe; Longcope, Donald B.; Tabbara, Mazen R.

    1999-05-03

    A procedure has been developed to represent the loading on a penetrator and its motion during oblique penetration into geologic media. The penetrator is modeled with the explicit dynamics, finite element computer program PRONTO 3D and the coupled pressure on the penetrator is given in a new loading option based on a separate cavity expansion (CE) solution that accounts for the pressure-reduction from a nearby target free surface. The free-surface influ- ence distance is selected in a predictive manner by considering the pressure to expand a spherical cavity in a finite radius sphere of the target material. The CE/PRONTO 3D procedure allows a detailed description of the penetrator for predicting shock environments or structural failure dur- ing the entire penetration event and is sufficiently rapid to be used in design optimization. It has been evaluated by comparing its results with data from two field tests of a full-scale penetrator into frozen soil at an impact angles of 49.6 and 52.5 degrees from the horizontal. The measured penetrator rotations were 24 and 22 degrees, respectively. In the simulation, the rotation was21 degrees and predominately resulted from the pressure reduction of the free surface. Good agree- ment was also found for the penetration depth and axial and lateral acceleration at two locations in the penetrator.

  3. Surfactant effects on cumulative drop size distributions produced by air bubbles bursting on a non-quiescent free surface

    NASA Astrophysics Data System (ADS)

    Parmar, K.; Liu, X.; Duncan, J. H.

    2013-11-01

    The generation of droplets when air bubbles travel upwards from within a liquid and burst at a free surface is studied experimentally. The bubbles are generated in a glass water tank that is 0.91 m long and 0.46 m wide with a water depth of 0.5 m. The tank is equipped with an acrylic box at its bottom that creates the bubble field using filtered air injected through an array of 180 hypodermic needles (0.33 mm ID). Two different surface conditions are created by using clean water and a 0.4% aqueous solution of Triton X-100 surfactant. Measurements of the bubble diameters as they approach the free surface are obtained with diffuse light shadowgraph images. The range of bubble diameters studied is 2.885 mm to 3.301 mm for clean water and 2.369 mm to 3.014 mm for the surfactant solution. A laser-light high-speed cinematic shadowgraph system is employed to record and measure the diameters and motions of the droplets at the free surface. This system can measure droplets with diameters <= 50 μm. The results show a clear distinction between the droplet distributions obtained in clean water and the surfactant solution. A bimodal droplet distribution is observed for clean water with at least two dominating peaks. For the surfactant solution, a single distribution peak is seen. This work is supported by the National Science Foundation, Division of Ocean Sciences.

  4. Lithium Redistribution in Lithium-Metal Batteries

    SciTech Connect

    Ferrese, A; Albertus, P; Christensen, J; Newman, J

    2012-01-01

    A model of a lithium-metal battery with a CoO2 positive electrode has been modeled in order to predict the movement of lithium in the negative electrode along the negative electrode/separator interface during cell cycling. A finite-element approach was used to incorporate an intercalation positive electrode using superposition, electrode tabbing, transport using concentrated solution theory, as well as the net movement of the lithium electrode during cycling. From this model, it has been found that movement of lithium along the negative electrode/separator interface does occur during cycling and is affected by three factors: the cell geometry, the slope of the open-circuit-potential function of the positive electrode, and concentration gradients in both the solid and liquid phases in the cell. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.027210jes] All rights reserved.

  5. Lithium purification technique

    DOEpatents

    Keough, R.F.; Meadows, G.E.

    1984-01-10

    A method for purifying liquid lithium to remove unwanted quantities of nitrogen or aluminum. The method involves precipitation of aluminum nitride by adding a reagent to the liquid lithium. The reagent will be either nitrogen or aluminum in a quantity adequate to react with the unwanted quantity of the impurity to form insoluble aluminum nitride. The aluminum nitride can be mechanically separated from the molten liquid lithium.

  6. Lithium purification technique

    DOEpatents

    Keough, Robert F.; Meadows, George E.

    1985-01-01

    A method for purifying liquid lithium to remove unwanted quantities of nitrogen or aluminum. The method involves precipitation of aluminum nitride by adding a reagent to the liquid lithium. The reagent will be either nitrogen or aluminum in a quantity adequate to react with the unwanted quantity of the impurity to form insoluble aluminum nitride. The aluminum nitride can be mechanically separated from the molten liquid lithium.

  7. Ammonia decomposition catalysis using lithium-calcium imide.

    PubMed

    Makepeace, Joshua W; Hunter, Hazel M A; Wood, Thomas J; Smith, Ronald I; Murray, Claire A; David, William I F

    2016-07-01

    Lithium-calcium imide is explored as a catalyst for the decomposition of ammonia. It shows the highest ammonia decomposition activity yet reported for a pure light metal amide or imide, comparable to lithium imide-amide at high temperature, with superior conversion observed at lower temperatures. Importantly, the post-reaction mass recovery of lithium-calcium imide is almost complete, indicating that it may be easier to contain than the other amide-imide catalysts reported to date. The basis of this improved recovery is that the catalyst is, at least partially, solid across the temperature range studied under ammonia flow. However, lithium-calcium imide itself is only stable at low and high temperatures under ammonia, with in situ powder diffraction showing the decomposition of the catalyst to lithium amide-imide and calcium imide at intermediate temperatures of 200-460 °C. PMID:27092374

  8. NASA lithium cell applications

    NASA Technical Reports Server (NTRS)

    Juvinall, G. L.

    1978-01-01

    The advantages of lithium systems are described and a general summary of their application in present and future NASA programs is presented. Benefits of the lithium systems include an increased payload weight and an increased cost effectiveness to the customer. This also allows for more flexibility in the design of future space transportation systems.

  9. Detection of trace organics in Martian soil analogs using fluorescence-free surface enhanced 1064-nm Raman Spectroscopy.

    PubMed

    Tang, Suning; Chen, Bin; McKay, Christopher P; Navarro-Gonzálezv, Rafael; Wang, Alan X

    2016-09-19

    A significant technology challenge in planetary missions is the in situ detection of organics at the sub-part-per-million (ppm) level in soils. This article reports the organic compound detection in Mars-like soils at the sub-ppm level using an ultra-sensitive spectral sensing technique based on fluorescence-free surface-enhanced Raman scattering (SERS), which has a significantly improved sensitivity and reduced fluorescence noise. Raman spectral detection of ppm level organics in Antarctic Dry Valley and Mojave Desert soils have been obtained for the first time, which otherwise are not detected by other Raman spectral techniques.

  10. Detection of trace organics in Martian soil analogs using fluorescence-free surface enhanced 1064-nm Raman Spectroscopy.

    PubMed

    Tang, Suning; Chen, Bin; McKay, Christopher P; Navarro-Gonzálezv, Rafael; Wang, Alan X

    2016-09-19

    A significant technology challenge in planetary missions is the in situ detection of organics at the sub-part-per-million (ppm) level in soils. This article reports the organic compound detection in Mars-like soils at the sub-ppm level using an ultra-sensitive spectral sensing technique based on fluorescence-free surface-enhanced Raman scattering (SERS), which has a significantly improved sensitivity and reduced fluorescence noise. Raman spectral detection of ppm level organics in Antarctic Dry Valley and Mojave Desert soils have been obtained for the first time, which otherwise are not detected by other Raman spectral techniques. PMID:27661945

  11. Cathode material for lithium batteries

    DOEpatents

    Park, Sang-Ho; Amine, Khalil

    2013-07-23

    A method of manufacture an article of a cathode (positive electrode) material for lithium batteries. The cathode material is a lithium molybdenum composite transition metal oxide material and is prepared by mixing in a solid state an intermediate molybdenum composite transition metal oxide and a lithium source. The mixture is thermally treated to obtain the lithium molybdenum composite transition metal oxide cathode material.

  12. Cathode material for lithium batteries

    DOEpatents

    Park, Sang-Ho; Amine, Khalil

    2015-01-13

    A method of manufacture an article of a cathode (positive electrode) material for lithium batteries. The cathode material is a lithium molybdenum composite transition metal oxide material and is prepared by mixing in a solid state an intermediate molybdenum composite transition metal oxide and a lithium source. The mixture is thermally treated to obtain the lithium molybdenum composite transition metal oxide cathode material.

  13. Lithium and autophagy.

    PubMed

    Motoi, Yumiko; Shimada, Kohei; Ishiguro, Koichi; Hattori, Nobutaka

    2014-06-18

    Lithium, a drug used to treat bipolar disorders, has a variety of neuroprotective mechanisms, including autophagy regulation, in various neuropsychiatric conditions. In neurodegenerative diseases, lithium enhances degradation of aggregate-prone proteins, including mutated huntingtin, phosphorylated tau, and α-synuclein, and causes damaged mitochondria to degrade, while in a mouse model of cerebral ischemia and Alzheimer's disease autophagy downregulation by lithium is observed. The signaling pathway of lithium as an autophagy enhancer might be associated with the mammalian target of rapamycin (mTOR)-independent pathway, which is involved in myo-inositol-1,4,5-trisphosphate (IP3) in Huntington's disease and Parkinson's disease. However, the mTOR-dependent pathway might be involved in inhibiting glycogen synthase kinase-3β (GSK3β) in other diseases. Lithium's autophagy-enhancing property may contribute to the therapeutic benefit of patients with neuropsychiatric disorders.

  14. Interaction of a strong blast wave with a free surface. [at ocean surface

    NASA Technical Reports Server (NTRS)

    Falade, A.; Holt, M.

    1978-01-01

    When a point source explosion is initiated at the ocean surface, the shock propagated into the water is reflected at the surface as a centered expansion wave. The solution in the neighborhood of the interaction point is obtained by writing the equations of motion in the appropriate similarity variables and then changing the independent variables to polar coordinates based at the interaction point. From the zero-order solution of the resulting equations the slopes of boundaries at the interaction point are obtained. A first-order perturbation of this solution provides more accurate representation of the flow variables and the curvature of the shock surface near the interaction point.

  15. Free-Surface and Contact Line Motion of Liquid in Microgravity

    NASA Technical Reports Server (NTRS)

    Schwartz, Leonard W.

    1996-01-01

    This project involves fundamental studies of the role of nonlinearity in determining the motion of liquid masses under the principal influences of surface tension, viscosity and inertia. Issues to be explored are relevant to aspects of terrestrial processes, as well as being immediately applicable to fluid management in a low-gravity environment. Specific issues include: (1) the mechanic's of liquid masses in large-amplitude motions, (2) the influence of bounding surfaces on the motion, and (3) the ability of such surfaces to control liquid motion by wetting forces, especially when they are augmented by various surface treatments. Mathematical techniques include asymptotic analysis of the governing equations, for problem simplification, and numerical simulation, using both boundary-element and finite-difference methods. The flow problem is divided into an 'outer' or inviscid potential-flow region and one or more inner, or viscous dominated, regions. Relevant to one inner region, the vicinity of the contact line, we discuss time-dependent simulation of slow droplet motion, on a surface of variable wettability, using the lubrication approximation. The simulation uses a disjoining pressure model and reproduces realistic wetting-dewetting behavior.

  16. Lithium metal oxide electrodes for lithium batteries

    DOEpatents

    Thackeray, Michael M.; Kim, Jeom-Soo; Johnson, Christopher S.

    2008-01-01

    An uncycled electrode for a non-aqueous lithium electrochemical cell including a lithium metal oxide having the formula Li.sub.(2+2x)/(2+x)M'.sub.2x/(2+x)M.sub.(2-2x)/(2+x)O.sub.2-.delta., in which 0.ltoreq.x<1 and .delta. is less than 0.2, and in which M is a non-lithium metal ion with an average trivalent oxidation state selected from two or more of the first row transition metals or lighter metal elements in the periodic table, and M' is one or more ions with an average tetravalent oxidation state selected from the first and second row transition metal elements and Sn. Methods of preconditioning the electrodes are disclosed as are electrochemical cells and batteries containing the electrodes.

  17. Zero-gravity Mean Free Surface Curvature of a Confined Liquid in a Radially-Vaned Container

    NASA Technical Reports Server (NTRS)

    Chen, Yongkang; Callahan, Michael; Weislogel, Mark

    2013-01-01

    A variety of increasingly intricate container geometries are under consideration for the passive manipulation of liquids aboard spacecraft where the impact of gravity may be neglected. In this study we examine the mean curvature of a liquid volume confined within a radial array of disconnected vanes of infinite extent. This particular geometry possesses a number of desirable characteristics relevant to waste water treatment aboard spacecraft for life support. It is observed that under certain conditions the slender shape of the free surface approaches an asymptote, which can be predicted analytically using new hybrid boundary conditions proposed herein. This contribution represents possibly the final extension of what has been referred to as the method of de Lazzer et al. (1996). The method enables the integration of the Young-Laplace equation over a domain with its boundaries, including the wetted portion of the solid boundaries, symmetry planes, and circular arcs representing free surfaces at the center plane of the liquid body. Asymptotic solutions at several limits are obtained and the analysis is confirmed with numerical computations.

  18. The Non-Linear Response of a Water Free Surface to a Pressure Distribution Moving at Constant Speed

    NASA Astrophysics Data System (ADS)

    Masnadi, N.; Duncan, J. H.; Akylas, T. R.

    2011-11-01

    The non-linear response of a water free surface to a localized pressure distribution moving at constant speed just below the minimum phase speed (Cmin) of gravity-capillary waves is studied experimentally. The experiments are performed in a tank that is 6 m long and 0.25 m wide with water depths ranging from 15 to 40 mm. The pressure distribution is generated by blowing air on the water surface via a vertically oriented 2-mm-ID tube that is mounted on an instrument carriage. The bottom of the tank is made of clear plastic and covered with translucent paper. A checkerboard pattern is printed on the paper and this pattern is viewed from above the water surface with a high-speed digital movie camera. The images of the checkerboard pattern are distorted by refraction at the water free surface and yield qualitative observations and quantitative measurements of the temporal evolution of the wave pattern. At towing speeds close to but below Cmin, a gravity-capillary lump appears behind the pressure source. For higher speeds, but still below Cmin an unsteady wave pattern consisting of a wide V is generated. At the boundary between the two response states, the pattern is asymmetric in the cross-stream direction. Above this boundary, lumps are shed from the tips of the V and the frequency of shedding increases with towing speed.

  19. On using the levelling of the free surface of a Newtonian fluid to measure viscosity and Navier slip length

    PubMed Central

    Gilormini, P.; Teyssèdre, H.

    2013-01-01

    Measuring the relaxation time involved in the levelling of a free surface of a Newtonian fluid laid on a substrate can give access to material parameters. It is shown here how most favourable pattern geometries of the free surface and film thicknesses can be defined for the measures of viscosity and Navier slip length at the fluid–solid interface, respectively. Moreover, we put special emphasis on the conditions required to avoid shear thinning by controlling the maximum shear rate. For initially sinusoidal patterns with infinitesimal amplitudes, an analytical solution including slip at the fluid–solid interface is used, and numerical simulations based on the natural element method allow one to discuss the effect of finite amplitudes. This leads to the definition of a relevance domain for the analytical solution that avoids the need for numerical simulations in practical applications. It is also shown how these results can be applied to crenelated profiles, where Fourier series expansion can be used, but with caution. PMID:24353474

  20. Apparatus and method for atmospheric pressure reactive atom plasma processing for shaping of damage free surfaces

    DOEpatents

    Carr; Jeffrey W.

    2009-03-31

    Fabrication apparatus and methods are disclosed for shaping and finishing difficult materials with no subsurface damage. The apparatus and methods use an atmospheric pressure mixed gas plasma discharge as a sub-aperture polisher of, for example, fused silica and single crystal silicon, silicon carbide and other materials. In one example, workpiece material is removed at the atomic level through reaction with fluorine atoms. In this example, these reactive species are produced by a noble gas plasma from trace constituent fluorocarbons or other fluorine containing gases added to the host argon matrix. The products of the reaction are gas phase compounds that flow from the surface of the workpiece, exposing fresh material to the etchant without condensation and redeposition on the newly created surface. The discharge provides a stable and predictable distribution of reactive species permitting the generation of a predetermined surface by translating the plasma across the workpiece along a calculated path.

  1. Node-pore sensing enables label-free surface-marker profiling of single cells.

    PubMed

    Balakrishnan, Karthik R; Whang, Jeremy C; Hwang, Richard; Hack, James H; Godley, Lucy A; Sohn, Lydia L

    2015-03-01

    Flow cytometry is a ubiquitous, multiparametric method for characterizing cellular populations. However, this method can grow increasingly complex with the number of proteins that need to be screened simultaneously: spectral emission overlap of fluorophores and the subsequent need for compensation, lengthy sample preparation, and multiple control tests that need to be performed separately must all be considered. These factors lead to increased costs, and consequently, flow cytometry is performed in core facilities with a dedicated technician operating the instrument. Here, we describe a low-cost, label-free microfluidic method that can determine the phenotypic profiles of single cells. Our method employs Node-Pore Sensing to measure the transit times of cells as they interact with a series of different antibodies, each corresponding to a specific cell-surface antigen, that have been functionalized in a single microfluidic channel. We demonstrate the capabilities of our method not only by screening two acute promyelocytic leukemia human cells lines (NB4 and AP-1060) for myeloid antigens, CD13, CD14, CD15, and CD33, simultaneously, but also by distinguishing a mixture of cells of similar size—AP-1060 and NALM-1—based on surface markers CD13 and HLA-DR. Furthermore, we show that our method can screen complex subpopulations in clinical samples: we successfully identified the blast population in primary human bone marrow samples from patients with acute myeloid leukemia and screened these cells for CD13, CD34, and HLA-DR. We show that our label-free method is an affordable, highly sensitive, and user-friendly technology that has the potential to transform cellular screening at the benchside.

  2. Node-pore sensing enables label-free surface-marker profiling of single cells.

    PubMed

    Balakrishnan, Karthik R; Whang, Jeremy C; Hwang, Richard; Hack, James H; Godley, Lucy A; Sohn, Lydia L

    2015-03-01

    Flow cytometry is a ubiquitous, multiparametric method for characterizing cellular populations. However, this method can grow increasingly complex with the number of proteins that need to be screened simultaneously: spectral emission overlap of fluorophores and the subsequent need for compensation, lengthy sample preparation, and multiple control tests that need to be performed separately must all be considered. These factors lead to increased costs, and consequently, flow cytometry is performed in core facilities with a dedicated technician operating the instrument. Here, we describe a low-cost, label-free microfluidic method that can determine the phenotypic profiles of single cells. Our method employs Node-Pore Sensing to measure the transit times of cells as they interact with a series of different antibodies, each corresponding to a specific cell-surface antigen, that have been functionalized in a single microfluidic channel. We demonstrate the capabilities of our method not only by screening two acute promyelocytic leukemia human cells lines (NB4 and AP-1060) for myeloid antigens, CD13, CD14, CD15, and CD33, simultaneously, but also by distinguishing a mixture of cells of similar size—AP-1060 and NALM-1—based on surface markers CD13 and HLA-DR. Furthermore, we show that our method can screen complex subpopulations in clinical samples: we successfully identified the blast population in primary human bone marrow samples from patients with acute myeloid leukemia and screened these cells for CD13, CD34, and HLA-DR. We show that our label-free method is an affordable, highly sensitive, and user-friendly technology that has the potential to transform cellular screening at the benchside. PMID:25625182

  3. Node-Pore Sensing Enables Label-Free Surface-Marker Profiling of Single Cells

    PubMed Central

    2015-01-01

    Flow cytometry is a ubiquitous, multiparametric method for characterizing cellular populations. However, this method can grow increasingly complex with the number of proteins that need to be screened simultaneously: spectral emission overlap of fluorophores and the subsequent need for compensation, lengthy sample preparation, and multiple control tests that need to be performed separately must all be considered. These factors lead to increased costs, and consequently, flow cytometry is performed in core facilities with a dedicated technician operating the instrument. Here, we describe a low-cost, label-free microfluidic method that can determine the phenotypic profiles of single cells. Our method employs Node-Pore Sensing to measure the transit times of cells as they interact with a series of different antibodies, each corresponding to a specific cell-surface antigen, that have been functionalized in a single microfluidic channel. We demonstrate the capabilities of our method not only by screening two acute promyelocytic leukemia human cells lines (NB4 and AP-1060) for myeloid antigens, CD13, CD14, CD15, and CD33, simultaneously, but also by distinguishing a mixture of cells of similar size—AP-1060 and NALM-1—based on surface markers CD13 and HLA-DR. Furthermore, we show that our method can screen complex subpopulations in clinical samples: we successfully identified the blast population in primary human bone marrow samples from patients with acute myeloid leukemia and screened these cells for CD13, CD34, and HLA-DR. We show that our label-free method is an affordable, highly sensitive, and user-friendly technology that has the potential to transform cellular screening at the benchside. PMID:25625182

  4. Lithium isotope fractionation by diffusion in minerals. Part 1: Pyroxenes

    NASA Astrophysics Data System (ADS)

    Richter, Frank; Watson, Bruce; Chaussidon, Marc; Mendybaev, Ruslan; Ruscitto, Dan

    2014-02-01

    Several recent studies found large lithium isotopic fractionations correlated with concentration gradients in pyroxene minerals from lava flows and mantle nodules that were interpreted as indicating diffusion of lithium into the grains. Motivated by these findings experiments were undertaken in which powdered spodumene (LiAlSi2O6) or Li2SiO3 was used to diffuse lithium into Templeton augite or Dekalb diopside grains at 900 °C and oxygen fugacity ranging from log fO2 = -17 to log fO2 = -12. The purpose of these experiments was to determine the diffusion coefficient of lithium in pyroxene minerals and to measure the isotopic fractionation of lithium in the diffusion boundary layer due to the relative mobility of 6Li compared to 7Li. The diffusion profiles of lithium that had not yet reached the center of Templeton augite grains were in most cases sharp steps propagating in from each boundary. In one case a more usual profile with smoothly decreasing lithium concentration with distance from the grain boundary was found. A model in which lithium occupies two different sites - one being fast diffusing interstitial lithium, the other much less mobile lithium in a metal site, reproduced both types of profiles. The step-like profiles arise in the model when interstitial lithium diffusing into the grain is strongly partitioned into abundant metal sites and thus does not penetrate further into the grain until all the metal sites at a given distance become filled. While the rate of propagation of the concentration step can be used to calculate an effective diffusivity for the penetration of lithium into the augite grains, the multiple speciation of lithium precludes making a separate precise determination of the diffusion coefficient of the interstitial lithium. Isotopic fractionations of 7Li/6Li of about 30‰ were found in the step-like diffusion boundary layers, which translate into a ratio of the isotope diffusion coefficients D/D=0.9592 (i.e., (6/7)β with β = 0

  5. Lithium cell test results

    NASA Technical Reports Server (NTRS)

    Bragg, B. J.

    1977-01-01

    Three lithium SO2 cells, two lithium CF cells, and a vinyl chloride cell, all with crimped seals, and all strictly experimental, were independently discharged on resistors. Three temperatures were used and several different storage temperatures. Discharge rate generally on the nominal discharges were 0.1 amp, 0.5 amp, and 1 amp. Tests results show that the crimp seals are inadequate, especially for the SO2 cells. Normal discharges present no hazards. All cells discharge to zero. The problem of lithium cell explosions, such as occurred during off-limits testing, is discussed.

  6. Lithium Dendrite Formation

    SciTech Connect

    2015-03-06

    Scientists at the Department of Energy’s Oak Ridge National Laboratory have captured the first real-time nanoscale images of lithium dendrite structures known to degrade lithium-ion batteries. The ORNL team’s electron microscopy could help researchers address long-standing issues related to battery performance and safety. Video shows annular dark-field scanning transmission electron microscopy imaging (ADF STEM) of lithium dendrite nucleation and growth from a glassy carbon working electrode and within a 1.2M LiPF6 EC:DM battery electrolyte.

  7. An angular fluidic channel for prism-free surface-plasmon-assisted fluorescence capturing

    NASA Astrophysics Data System (ADS)

    Nomura, Ken-Ichi; Gopinath, Subash C. B.; Lakshmipriya, Thangavel; Fukuda, Nobuko; Wang, Xiaomin; Fujimaki, Makoto

    2013-12-01

    Surface plasmon excitation provides stronger enhancement of the fluorescence intensity and better sensitivity than other sensing approaches but requires optimal positioning of a prism to ensure optimum output of the incident light. Here we describe a simple, highly sensitive optical sensing system combining surface plasmon excitation and fluorescence to address this limitation. V-shaped fluidic channels are employed to mimic the functions of a prism, sensing plate, and flow channel in a single setup. Superior performance is demonstrated for different biomolecular recognition reactions on a self-assembled monolayer, and the sensitivity reaches 100 fM for biotin-streptavidin interactions. Using an antibody as a probe, we demonstrate the detection of intact influenza viruses at 0.2 HA units ml-1 levels. The convenient sensing system developed here has the advantages of being prism-free and requiring less sample (1-2 μl), making this platform suitable for use in situations requiring low sample volumes.

  8. Lithium metal oxide electrodes for lithium batteries

    SciTech Connect

    Thackeray, Michael M.; Johnson, Christopher S.; Amine, Khalil; Kang, Sun-Ho

    2010-06-08

    An uncycled preconditioned electrode for a non-aqueous lithium electrochemical cell including a lithium metal oxide having the formula xLi.sub.2-yH.sub.yO.xM'O.sub.2.(1-x)Li.sub.1-zH.sub.zMO.sub.2 in which 0lithium metal ion with an average trivalent oxidation state selected from two or more of the first row transition metals or lighter metal elements in the periodic table, and M' is one or more ions with an average tetravalent oxidation state selected from the first and second row transition metal elements and Sn. The xLi.sub.2-yH.sub.y.xM'O.sub.2.(1-x)Li.sub.1-zH.sub.zMO.sub.2 material is prepared by preconditioning a precursor lithium metal oxide (i.e., xLi.sub.2M'O.sub.3.(1-x)LiMO.sub.2) with a proton-containing medium with a pH<7.0 containing an inorganic acid. Methods of preparing the electrodes are disclosed, as are electrochemical cells and batteries containing the electrodes.

  9. Flow rate limitation in open capillary channel flows.

    PubMed

    Haake, Dennis; Rosendahl, Uwe; Ohlhoff, Antje; Dreyer, Michael E

    2006-09-01

    This paper reports the experimental and theoretical investigations of forced liquid flows through open capillary channels under reduced gravity conditions. An open capillary channel is a structure that establishes a liquid flow path at low Bond numbers, when the capillary pressure caused by the surface tension force dominates in comparison to the hydrostatic pressure induced by gravitational or residual accelerations. In case of steady flow through the channel, the capillary pressure of the free surface balances the pressure difference between the liquid and the surrounding constant-pressure gas phase. Because of convective and viscous momentum transport, the pressure along the flow path decreases and causes the free surface to bend inward. The maximum flow rate is achieved when the free surface collapses and gas ingestion occurs at the outlet. This critical flow rate depends on the geometry of the channel and the properties of the liquid. In this paper we present a comparison of the theoretical and experimental critical flow rates and surface profiles for convective dominated flows. For the prediction of the critical flow rate a one-dimensional theoretical model taking into account the entrance pressure loss and the frictional pressure loss in the channel is developed.

  10. APPARATUS FOR THE PRODUCTION OF LITHIUM METAL

    DOEpatents

    Baker, P.S.; Duncan, F.R.; Greene, H.B.

    1961-08-22

    Methods and apparatus for the production of high-purity lithium from lithium halides are described. The apparatus is provided for continuously contacting a molten lithium halide with molten barium, thereby forming lithium metal and a barium halide, establishing separate layers of these reaction products and unreacted barium and lithium halide, and continuously withdrawing lithium and barium halide from the reaction zone. (AEC)

  11. Lithium drifted germanium system

    NASA Technical Reports Server (NTRS)

    Fjarlie, E. J.

    1969-01-01

    General characteristics of the lithium-drifted germanium photodiode-Dewar-preamplifier system and particular operating instructions for the device are given. Information is included on solving operational problems.

  12. Toward a Full Simulation of the Basic Oxygen Furnace: Deformation of the Bath Free Surface and Coupled Transfer Processes Associated with the Post-Combustion in the Gas Region

    NASA Astrophysics Data System (ADS)

    Doh, Y.; Chapelle, P.; Jardy, A.; Djambazov, G.; Pericleous, K.; Ghazal, G.; Gardin, P.

    2013-06-01

    The present article treats different phenomena taking place in a steelmaking converter through the development of two separate models. The first model describes the cavity produced at the free surface of the metal bath by the high-speed impinging oxygen jet. The model is based on a zonal approach, where gas compressibility effects are taken into account only in the high velocity jet region, while elsewhere the gas is treated as incompressible. The volume of fluid (VOF) method is employed to follow the deformation of the bath free surface. Calculations are presented for two- and three-phase systems and compared against experimental data obtained in a cold model experiment presented in the literature. The influence on the size and shape of the cavity of various parameters and models (including the jet inlet boundary conditions, the VOF advection scheme, and the turbulence model) is studied. Next, the model is used to simulate the interaction of a supersonic oxygen jet with the surface of a liquid steel bath in a pilot-scale converter. The second model concentrates on fluid flow, heat transfer, and the post-combustion reaction in the gas phase above the metal bath. The model uses the simple chemical reaction scheme approach to describe the transport of the chemical species and takes into account the consumption of oxygen by the bath and thermal radiative transfer. The model predictions are in reasonable agreement with measurements collected in a laboratory experiment and in a pilot-scale furnace.

  13. Lithium counterdoped silicon solar cell

    NASA Technical Reports Server (NTRS)

    Weinberg, I. (Inventor); Brandhorst, H. W., Jr. (Inventor)

    1986-01-01

    The resistance to radiation damage of an n(+)p boron doped silicon solar cell is improved by lithium counterdoping. Even though lithium is an n-dopant in silicon, the lithium is introduced in small enough quantities so that the cell base remains p-type. The lithium is introduced into the solar cell wafer by implantation of lithium ions whose energy is about 50 keV. After this lithium implantation, the wafer is annealed in a nitrogen atmosphere at 375 C for two hours.

  14. Aluminum-lithium for aerospace

    SciTech Connect

    Fielding, P.S.; Wolf, G.J.

    1996-10-01

    Aluminum-lithium alloys were developed primarily to reduce the weight of aircraft and aerospace structures. Lithium is the lightest metallic element, and each 1% of lithium added to aluminum reduces alloy density by about 3% and increases modulus by about 5%. Though lithium has a solubility limit of 4.2% in aluminum, the amount of lithium ranges between 1 and 3% in commercial alloys. Aluminum-lithium alloys are most often selected for aerospace components because of their low density, high strength, and high specific modulus. However, other applications now exploit their excellent fatigue resistance and cryogenic toughness.

  15. Solid-state lithium battery

    DOEpatents

    Ihlefeld, Jon; Clem, Paul G; Edney, Cynthia; Ingersoll, David; Nagasubramanian, Ganesan; Fenton, Kyle Ross

    2014-11-04

    The present invention is directed to a higher power, thin film lithium-ion electrolyte on a metallic substrate, enabling mass-produced solid-state lithium batteries. High-temperature thermodynamic equilibrium processing enables co-firing of oxides and base metals, providing a means to integrate the crystalline, lithium-stable, fast lithium-ion conductor lanthanum lithium tantalate (La.sub.1/3-xLi.sub.3xTaO.sub.3) directly with a thin metal foil current collector appropriate for a lithium-free solid-state battery.

  16. Free-Surface Optical Scattering as an Indicator of the Shock-Induced Solid-Liquid Phase Transition in Tin

    SciTech Connect

    Stevens, G. D.; Lutz, S. S.; Marshall, B. R.; Turley, W. D.; Veeser, L. R.; Furlanetto, M. R.; Hixson, R. S.; Holtkamp, D. B.; Jensen, B. J.; Rigg, P. A.; Wilke, M. D.

    2008-07-01

    When highly polished metal surfaces melt upon release after shock loading, they exhibit features that suggest significant surface changes accompany the phase transition. The reflection of light from such surfaces changes from specular (pre-shock) to diffuse upon melting. A familiar manifestation of this phenomenon is the loss of signal light in VISAR measurements, which occurs at pressures high enough to melt the free surface. Unlike many other potential material phase-sensitive diagnostics (e.g., reflectometry, conductivity) that show relatively small (1%–10%) changes, the specularity of reflection provides a more sensitive and definitive indication of the solid-liquid phase transition. Data will be presented that support the hypothesis that specularity changes indicate melt in a way that can be measured easily and unambiguously.

  17. Interaction of small mobile stacking fault tetrahedra with free surfaces, dislocations, and interfaces in Cu and Cu-Nb

    NASA Astrophysics Data System (ADS)

    Martínez, Enrique; Uberuaga, Blas P.; Beyerlein, Irene J.

    2016-02-01

    The presence of stacking fault tetrahedra (SFTs) in face-centered-cubic metals substantially modifies the material response to external loading. These defects are extremely stable with increasing energetic stability as they grow in size. At the sizes visible within a transmission electron microscope, they appear nearly immobile. We have recently shown that these defects might indeed migrate, with defective SFTs exhibiting particularly high mobilities. In this paper, using molecular dynamics, we show how mobile SFTs interact with various types of extended defects, including free surfaces, dislocations, and interfaces in Cu and Cu-Nb systems. We observe a direct relation between the energetics of a single vacancy interacting with each external defect and the propensity for the SFT to be absorbed. Finally, using mesoscale modeling, we show how the fact that SFTs can migrate influences the system evolution and potentially important observables of interest such as the void denuded zones around defect sinks.

  18. Growth of GaAs from a free surface melt under controlled arsenic pressure in a partially confined configuration

    NASA Technical Reports Server (NTRS)

    Gatos, H. C.; Lagowski, J.; Wu, Y.

    1988-01-01

    A partially confined configuration for the growth of GaAs from melt in space was developed, consisting of a triangular prism containing the seed crystal and source material in the form of a rod. It is suggested that the configuration overcomes two obstacles in the growth of GaAs in space: total confinement in a quartz crucible and lack of arsenic pressure control. Ground tests of the configuration show that it is capable of crystal growth in space and is useful for studying the growth of GaAs from a free-surface melt on earth. The resulting chemical composition, electrical property variations, and phenomenological models to account for the results are presented.

  19. Verification and transfer of thermal pollution model. Volume 2: User's manual for 3-dimensional free-surface model

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Sengupta, S.; Tuann, S. Y.; Lee, C. R.

    1982-01-01

    The six-volume report: describes the theory of a three-dimensional (3-D) mathematical thermal discharge model and a related one-dimensional (1-D) model, includes model verification at two sites, and provides a separate user's manual for each model. The 3-D model has two forms: free surface and rigid lid. The former, verified at Anclote Anchorage (FL), allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth; e.g., estuaries and coastal regions. The latter, verified at Lake Keowee (SC), is suited for small surface wave heights compared to depth. These models allow computation of time-dependent velocity and temperature fields for given initial conditions and time-varying boundary conditions.

  20. Instabilities and bifurcations due to buoyancy in a cylindrical container heated from below with and without a free surface

    NASA Astrophysics Data System (ADS)

    El Gallaf, Anas; Touihri, Ridha; Henry, Daniel; Ben Hadid, Hamda

    2009-11-01

    Three-dimensional simulations of the buoyant convection in a cylindrical container heated from below are presented. Both the thresholds for the onset of the convection and the nonlinear evolution of this convection are calculated. The simulations concern two configurations: a cavity with a rigid upper surface (Rigid-Rigid case) and a cavity with a non-constrained free surface (Rigid-Free case). The results show a similar variation of the primary thresholds with the aspect ratio for the two configurations. In contrast, the nonlinear evolution of the convection is much changed between the two configurations. In particular, subcritical secondary branches with a very large subcriticity are obtained in the R-F case. To cite this article: A. El Gallaf et al., C. R. Mecanique 337 (2009).

  1. Lithium battery management system

    DOEpatents

    Dougherty, Thomas J.

    2012-05-08

    Provided is a system for managing a lithium battery system having a plurality of cells. The battery system comprises a variable-resistance element electrically connected to a cell and located proximate a portion of the cell; and a device for determining, utilizing the variable-resistance element, whether the temperature of the cell has exceeded a predetermined threshold. A method of managing the temperature of a lithium battery system is also included.

  2. Lithium to the Rescue.

    PubMed

    Jope, Richard S; Nemeroff, Charles B

    2016-01-01

    Lithium, an element that Mother Nature has put in some drinking water sources, has been used for its curative powers for centuries. Today, it's given in capsule form as a mood stabilizer for bipolar disorder and depression. New research, however, reveals its role as a neuroprotector, and suggests that a better understanding of the role enzymes modulated by lithium play could lead to new treatments for Alzheimer's disease, Parkinson's disease, multiple sclerosis, and other neurodegenerative disorders. PMID:27408673

  3. [Neuroprotective actions of lithium].

    PubMed

    Hashimoto, Ryota; Fujimaki, Koichiro; Jeong, Mi Ra; Senatorov, Vladimir V; Christ, Lori; Leeds, Peter; Chuang, De-Maw; Takeda, Masatoshi

    2003-01-01

    Lithium has long been one of the primary drugs used to treat bipolar mood disorder. However, neither the etiology of this disease nor the therapeutic mechanism(s) of this drug is well understood. Several lines of clinical evidence suggest that lithium has neurotrophic actions. For example chronic lithium treatment increases the volume of gray matter and the content of N-acetyl-aspartate, a cell survival marker, in bipolar mood disorder patients (Moore et al., 2000). Moreover, treatment with this mood-stabilizer suppresses the decrease in the volume of the subgenual pre-frontal cortex found in bipolar patients (Drevets, 2001). To elucidate molecular mechanisms underlying the neuroprotective and neurotrophic actions of lithium, we employed a preparation of cultured cortical neurons prepared form embryonic rats. We found that treatment with therapeutic doses (0.2-1.2 mM) of lithium robustly protects cortical neurons from multiple insults, notably glutamate-induced excitotoxicity. The neuroprotection against glutamate excitotoxicity is time-dependent, requiring treatment for 5-6 days for maximal effect, and is associated with a reduction in NMDA receptor-mediated Ca2+ influx. The latter is correlated with a decrease in Tyrosine 1472 phosphorylation levels in the NR2B subunit of NMDA receptors and a loss of Src kinase activity which is involved in NR2B tyrosine phosphorylation. Neither the activity of total tyrosine protein kinase nor that of tyrosine protein phosphatase is affected by this drug, indicating the selectivity of the modulation. Lithium neuroprotection against excitotoxicity is inhibited by a BDNF-neutralizing antibody and K252a, a Trk antagonist. Lithium treatment time-dependently increases the intracellular level of BDNF in cortical neurons and activates its receptor, TrkB. The neuroprotection can be completely blocked by either heterozygous or homozygous knockout of the BDNF gene. These results suggest a central role of BDNF and TrkB in mediating the

  4. Hydrogen Outgassing from Lithium Hydride

    SciTech Connect

    Dinh, L N; Schildbach, M A; Smith, R A; Balazs1, B; McLean II, W

    2006-04-20

    Lithium hydride is a nuclear material with a great affinity for moisture. As a result of exposure to water vapor during machining, transportation, storage and assembly, a corrosion layer (oxide and/or hydroxide) always forms on the surface of lithium hydride resulting in the release of hydrogen gas. Thermodynamically, lithium hydride, lithium oxide and lithium hydroxide are all stable. However, lithium hydroxides formed near the lithium hydride substrate (interface hydroxide) and near the sample/vacuum interface (surface hydroxide) are much less thermally stable than their bulk counterpart. In a dry environment, the interface/surface hydroxides slowly degenerate over many years/decades at room temperature into lithium oxide, releasing water vapor and ultimately hydrogen gas through reaction of the water vapor with the lithium hydride substrate. This outgassing can potentially cause metal hydriding and/or compatibility issues elsewhere in the device. In this chapter, the morphology and the chemistry of the corrosion layer grown on lithium hydride (and in some cases, its isotopic cousin, lithium deuteride) as a result of exposure to moisture are investigated. The hydrogen outgassing processes associated with the formation and subsequent degeneration of this corrosion layer are described. Experimental techniques to measure the hydrogen outgassing kinetics from lithium hydride and methods employing the measured kinetics to predict hydrogen outgassing as a function of time and temperature are presented. Finally, practical procedures to mitigate the problem of hydrogen outgassing from lithium hydride are discussed.

  5. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    DOE PAGES

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A.

    2015-12-21

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through themore » systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Lastly, our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries.« less

  6. Engineering Heteromaterials to Control Lithium Ion Transport Pathways.

    PubMed

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A

    2015-01-01

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through the systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries. PMID:26686655

  7. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A.

    2015-12-01

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through the systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries.

  8. Liquid Lithium Wall Experiments in CDX-U

    SciTech Connect

    R. Doerner; R. Kaita; R. Majeski; S. Luckhardt; et al

    1999-10-01

    The concept of a flowing lithium first wall for a fusion reactor may lead to a significant advance in reactor design, since it could virtually eliminate the concerns with power density and erosion, tritium retention, and cooling associated with solid walls. Sputtering and erosion tests are currently underway in the PISCES device at the University of California at San Diego (UCSD). To complement this effort, plasma interaction questions in a toroidal plasma geometry will be addressed by a proposed new groundbreaking experiment in the Current Drive eXperiment-Upgrade (CDX-U) spherical torus (ST). The CDX-U plasma is intensely heated and well diagnosed, and an extensive liquid lithium plasma-facing surface will be used for the first time with a toroidal plasma. Since CDX-U is a small ST, only approximately1 liter or less of lithium is required to produce a toroidal liquid lithium limiter target, leading to a quick and cost-effective experiment.

  9. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    SciTech Connect

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A.

    2015-12-21

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through the systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Lastly, our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries.

  10. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    PubMed Central

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A.

    2015-01-01

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through the systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries. PMID:26686655

  11. Rechargeable ambient temperature lithium cells

    NASA Technical Reports Server (NTRS)

    Holleck, G. L.

    1980-01-01

    The cycling performance of a secondary lithium cell with a 2-methyl THF lithium hectofluorarsenate electrolyte is discussed. Stripping efficiency, dendritization, passivation on standing, and discharge efficiency are considered.

  12. Lithium: for harnessing renewable energy

    USGS Publications Warehouse

    Bradley, Dwight; Jaskula, Brian W.

    2014-01-01

    Lithium, which has the chemical symbol Li and an atomic number of 3, is the first metal in the periodic table. Lithium has many uses, the most prominent being in batteries for cell phones, laptops, and electric and hybrid vehicles. Worldwide sources of lithium are broken down by ore-deposit type as follows: closed-basin brines, 58%; pegmatites and related granites, 26%; lithium-enriched clays, 7%; oilfield brines, 3%; geothermal brines, 3%; and lithium-enriched zeolites, 3% (2013 statistics). There are over 39 million tons of lithium resources worldwide. Of this resource, the USGS estimates there to be approximately 13 million tons of current economically recoverable lithium reserves. To help predict where future lithium supplies might be located, USGS scientists study how and where identified resources are concentrated in the Earth’s crust, and they use that knowledge to assess the likelihood that undiscovered resources also exist.

  13. US Navy lithium cell applications

    NASA Technical Reports Server (NTRS)

    Bowers, F. M.

    1978-01-01

    Applications of lithium systems that are already in the fleet are discussed. The approach that the Navy is taking in the control of the introduction of lithium batteries into the fleet is also discussed.

  14. Particle-depletion dynamics in axisymmetric thermocapillary flows

    NASA Astrophysics Data System (ADS)

    Kuhlmann, H. C.; Lemée, T.

    2015-03-01

    The removal of suspended particles from the interior of a thermocapillary liquid bridge via a finite-particle-size effect restricting the particle motion near the free surface is analyzed in the framework of a model flow. The particle depletion occurs on the same short time scale as does the particle accumulation in experiments. Furthermore, the time scale diverges in a similar manner for decreasing particle size. The dependence of the time scale for particle accumulation on the particle size is explained in terms of a diverging return time to the free surface for those finite-size particles which are subject to the particle-free surface-interaction.

  15. Lithium question for nuclear fusion

    SciTech Connect

    Shieh, P.S.S.

    1981-01-01

    An attempt is made to estimate the lithium reserve (the economically recoverable lithium) for the tritium breeding in D-T fusion reactors and other uses. Similar development patterns for fusion energy and fission energy are assumed to estimate the future lithium requirements. These requirements are grouped into three categories; the commercial uses, the lithium batteries for electric cars, and the fusion reactor uses. 5 refs.

  16. Lithium-system corrosion/erosion studies for the FMIT project

    SciTech Connect

    Bazinet, G D

    1983-04-01

    The corrosion behavior of selected materials in a liquid lithium environment has been studied in support of system and component designs for the Fusion Materials Irradiation Test (FMIT) Facility. The liquid lithium test resources and the capabilities of several laboratories were used to study specific concerns associated with the overall objective. Testing conditions ranged from approx. 3700 hours to approx. 6500 hours of exposure to flowing lithium at temperatures from 230/sup 0/C to 270/sup 0/C and static lithium at temperatures from 200/sup 0/C to 500/sup 0/C. Principal areas of investigation included lithium corrosion/erosion effects of FMIT lithium system materials (largely Type 304 and Type 304L austenitic stainless steels) and candidate materials for major system components.

  17. Effect of a gas on the ejection of particles from the free surface of a sample subjected to a shock wave with various intensities

    NASA Astrophysics Data System (ADS)

    Ogorodnikov, V. A.; Mikhailov, A. L.; Sasik, V. S.; Erunov, S. V.; Syrunin, M. A.; Fedorov, A. V.; Nevmerzhitskii, N. V.; Kulakov, E. V.; Kleshchevnikov, O. A.; Antipov, M. V.; Yurtov, I. V.; Rudnev, A. V.; Chapaev, A. V.; Pupkov, A. S.; Sen'kovskii, E. D.; Sotskov, E. A.; Glushikhin, V. V.; Kalashnik, I. A.; Finyushin, S. A.; Chudakov, E. A.; Kalashnikov, D. A.

    2016-08-01

    In view of the possible effect of contamination of a plasma by metal particles on the operation of a number of facilities or on the detection of the motion of liners by Doppler methods, a particular attention has been recently focused on the problem of the ejection of particles from the shock-loaded free surface of a sample or on the "dusting" problem. Most information concerns the dusting source associated with the roughness of the surface, manufacturing technology, and the defectiveness and aging of a material. Factors affecting this process such as the profile and amplitude of the pressure on the front of the shock wave arriving at the free surface of the sample, the presence of the gas in front of the free surface, and the pressure in this gas are less studied.

  18. On Faraday Instability in Magnetic Liquids: Ince-Erdelyi Approach Applied to the Hill Equation Describing Oscillations of a Ferrofluid Free Surface

    NASA Astrophysics Data System (ADS)

    Hennenberg, M.; Slavtchev, S.; Valchev, G.

    2013-12-01

    When an isothermal ferrofluid is submitted to an oscillating magnetic field, the initially motionless liquid free surface can start to oscillate. This physical phenomenon is similar to the Faraday instability for usual Newtonian liquids subjected to a mechanical oscillation. In the present paper, we consider the magnetic field as a sum of a constant part and a time periodic part. Two different cases for the constant part of the field, being vertical in the first one or horizontal in the second one are studied. Assuming both ferrofluid magnetization and magnetic field to be collinear, we develop the linear stability analysis of the motionless reference state taking into account the Kelvin magnetic forces. The Laplace law describing the free surface deformation reduces to Hill's equation, which is studied using the classical method of Ince and Erdelyi. Inside this framework, we obtain the transition conditions leading to the free surface oscillations.

  19. Stability of the lithium 'waterfall' first wall protection concept for inertial confinement fusion reactors

    SciTech Connect

    Esser, P.D.; Paul, D.D.; Abdel-Khalik, S.I.

    1981-01-01

    Uncertainties regarding the feasibility of using an annular waterfall of liquid lithium to protect the first wall in inertial confinement fusion reactor cavities have prompted a theoretical investigation of annular jet stability. Infinitesimal perturbation techniques are applied to an idealized model of the jet with disturbances acting upon either or both of the free surfaces. Dispersion relations are derived that predict the range of disturbance frequencies leading to instability, as well as the perturbation growth rates and jet break-up length. The results are extended to turbulent annular jets and are evaluated for the lithium waterfall design. It is concluded that inherent instabilities due to turbulent fluctuations will not cause the jet to break up over distances comparable to the height of the reactor cavity.

  20. Stability of the lithium ''WATERFALL'' first wall protection concept for inertial confinement fusion reactors

    SciTech Connect

    Esser, P.D.; Abel-Khalik, S.I.; Paul, D.D.

    1981-04-01

    Uncertainties regarding the feasibility of using an annular ''waterfall'' of liquid lithium to protect the first wall in inertial confinement fusion reactor cavities have prompted a theoretical investigation of annular jet stability. Infinitesimal perturbation techniques are applied to an idealized model of the jet with disturbances acting upon either or both of the free surfaces. Dispersion relations are derived that predict the range of disturbance frequencies leading to instability, as well as the perturbation growth rates and jet breakup length. The results are extended to turbulent annular jets and are evaluated for the lithium waterfall design. It is concluded that inherent instabilities due to turbulent fluctuations will not cause the jet to break up over distances comparable to the height of the reactor cavity.

  1. A perspective on experimental findings and theoretical explanations of novel dynamics at free surface and in freestanding thin films of polystyrene

    NASA Astrophysics Data System (ADS)

    Ngai, Kia L.; Prevosto, Daniele; Capaccioli, Simone

    2016-03-01

    Most studies of the dynamics at the surface and in thin films of polystyrene (PS) are focused on the change of glass transition temperature from the bulk value. In this perspective, we highlight three new developments in research on the dynamics of PS in high molecular weight (MW) freestanding PS thin films and at the surface of low MW PS. Novel findings from these developments require consideration of viscoelastic mechanisms with length scales longer than the segmental α-relaxation. The first development is the creep compliance measurements of high-MW PS thin films, probing not only the segmental α-relaxation, but also the polymer chain modes at higher compliance levels, including the sub-Rouse modes and the Rouse modes. The compliance data indicate the relaxation times of the sub-Rouse modes are reduced in thinner films like that of the segmental α-relaxation but to a much less extent. The second development is the novel observation of two glass transitions in freestanding polystyrene thin films by ellipsometry. The upper and lower glass transitions occurs, respectively, at temperatures ? and ?, both are below the bulk glass transition temperature. While the lower transition at ? is associated with the segmental α-relaxation, the only viable explanation of the origin of the upper transition at ? is from another intrinsic viscoelastic mechanism of PS, and not at different location of the film. Supported by various experiments on PS and other polymers, we show that the sub-Rouse modes are cooperative and coupled to density, and hence giving rise to the upper glass transition in freestanding PS films. The sub-Rouse relaxation times will increase on physical ageing, and bring along an increase in density of the freestanding film due to the coupling. This prediction can be checked by performing ageing experiment. The third development is the reduction of viscosity at the free surface of low MW PS. Since viscous flow of low MW PS is definitely carried out by the

  2. A review of lithium deposition in lithium-ion and lithium metal secondary batteries

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Huang, Jun; Yann Liaw, Bor; Metzler, Viktor; Zhang, Jianbo

    2014-05-01

    Major aspects related to lithium deposition in lithium-ion and lithium metal secondary batteries are reviewed. For lithium-ion batteries with carbonaceous anode, lithium deposition may occur under harsh charging conditions such as overcharging or charging at low temperatures. The major technical solutions include: (1) applying electrochemical models to predict the critical conditions for deposition initiation; (2) preventions by improved battery design and material modification; (3) applying adequate charging protocols to inhibit lithium deposition. For lithium metal secondary batteries, the lithium deposition is the inherent reaction during charging. The major technical solutions include: (1) the use of mechanistic models to elucidate and control dendrite initiation and growth; (2) engineering surface morphology of the lithium deposition to avoid dendrite formation via adjusting the composition and concentration of the electrolyte; (3) controlling battery working conditions. From a survey of the literature, the areas that require further study are proposed; e.g., refining the lithium deposition criteria, developing an effective AC self pre-heating method for low-temperature charging of lithium-ion batteries, and clarifying the role the solid electrolyte interphase (SEI) plays in determining the deposition morphology; to facilitate a refined control of the lithium deposition.

  3. Lithium overdosage and related tests.

    PubMed

    Pigatto, Paolo D; Dell'Osso, Bernardo; Guzzi, Gianpaolo

    2016-12-01

    Lithium acts biochemically through the inositol depletion in brain cortex. At low doses, however, it is partly effective and/or ineffective, whereas in high concentrations is toxic. We would like to make one point about this review. In fact, in our view, the patient should be given a support to correct hypernatremia and even sodium levels should be tested serially-along with serum lithium concentrations-because high sodium levels reduce the rate of elimination of lithium. Lithium is mainly a neurotoxicant. Lithium-related central nervous system toxicity as well as the cardiovascular and thyroid changes are most likely due to the cations (Na2 (+) and K(+)) competition. PMID:26753697

  4. Lithium Dinitramide as an Additive in Lithium Power Cells

    NASA Technical Reports Server (NTRS)

    Gorkovenko, Alexander A.

    2007-01-01

    Lithium dinitramide, LiN(NO2)2 has shown promise as an additive to nonaqueous electrolytes in rechargeable and non-rechargeable lithium-ion-based electrochemical power cells. Such non-aqueous electrolytes consist of lithium salts dissolved in mixtures of organic ethers, esters, carbonates, or acetals. The benefits of adding lithium dinitramide (which is also a lithium salt) include lower irreversible loss of capacity on the first charge/discharge cycle, higher cycle life, lower self-discharge, greater flexibility in selection of electrolyte solvents, and greater charge capacity. The need for a suitable electrolyte additive arises as follows: The metallic lithium in the anode of a lithium-ion-based power cell is so highly reactive that in addition to the desired main electrochemical reaction, it engages in side reactions that cause formation of resistive films and dendrites, which degrade performance as quantified in terms of charge capacity, cycle life, shelf life, first-cycle irreversible capacity loss, specific power, and specific energy. The incidence of side reactions can be reduced through the formation of a solid-electrolyte interface (SEI) a thin film that prevents direct contact between the lithium anode material and the electrolyte. Ideally, an SEI should chemically protect the anode and the electrolyte from each other while exhibiting high conductivity for lithium ions and little or no conductivity for electrons. A suitable additive can act as an SEI promoter. Heretofore, most SEI promotion was thought to derive from organic molecules in electrolyte solutions. In contrast, lithium dinitramide is inorganic. Dinitramide compounds are known as oxidizers in rocket-fuel chemistry and until now, were not known as SEI promoters in battery chemistry. Although the exact reason for the improvement afforded by the addition of lithium dinitramide is not clear, it has been hypothesized that lithium dinitramide competes with other electrolyte constituents to react with

  5. Free surface liquid films of binary mixtures. Two-dimensional steady structures at off-critical compositions

    NASA Astrophysics Data System (ADS)

    Bribesh, Fathi A. M.; Madruga, Santiago

    2016-03-01

    We present steady non-linear solutions of films of confined polymer blends deposited on a solid substrate at off-critical concentrations with a free deformable surface. The solutions are obtained numerically using a variational form of the Cahn-Hilliard equation in the static limit, which allows for internal diffuse interfaces between the two components of the mixture. Existence of most of the branches of non-linear solutions at off-critical concentrations can be predicted from the knowledge of the branching points obtained with a linear stability analysis plus the non-linear solutions at critical concentrations. However, some families of solutions are found not to have correspondence at critical compositions. We take a value for surface tension that allows strong deformations at the sharp free upper surface. Varying the average composition and the length and thickness of the films we find a rich morphology of static films in the form of laterally structure films, layered films, droplets on the substrate, droplets at the free surface, and checkerboard structures. We show that laterally structured solutions are energetically favorable over homogeneous and other structured solutions within the whole spinodal region and even close to the absolute stability binodal boundary.

  6. Label-free surface-enhanced Raman scattering strategy for rapid detection of penicilloic acid in milk products.

    PubMed

    Qi, Meihui; Huang, Xiaoyan; Zhou, Yujie; Zhang, Liying; Jin, Yang; Peng, Yan; Jiang, Huijun; Du, Shuhu

    2016-04-15

    A label-free surface-enhanced Raman scattering (SERS) strategy based on silver-coated gold nanoparticles (Au@Ag NPs) was developed for rapid detection of penicilloic acid (PA) in milk products. It has been demonstrated that core size and shell thickness of Au@Ag NPs are two critical variants affecting enhancement of Raman signals by coupling of two plasma resonance absorption. The Au@Ag NPs with 26-nm core and 9-nm Ag shell exhibit excellent Raman enhancement, in particular, upon the formation of hot spots through NPs aggregation induced by interaction between target molecules and Au@Ag NPs. Compared to the early studies limited to laboratory settings, our analytical approach is simple (without sample pretreatment), less time-consuming (within ∼3 min) and inexpensive. The limit of detection of PA is 3.00 ppm, 3.00 ppm and 4.00 ppm in liquid milk, yogurt and milk powder, respectively. The label-free SERS technique offers a potential for the on-site monitoring of chemical contaminants in milk products. PMID:26617009

  7. Controlled synthesis of buried delta-layers of Ag nanocrystals for near-field plasmonic effects on free surfaces

    SciTech Connect

    Benzo, Patrizio; Bonafos, Caroline; Bayle, Maxime; Carles, Robert; Cattaneo, Laura; Benassayag, Gerard; Pecassou, Beatrice; Farcau, Cosmin; Muller, Dominique

    2013-05-21

    We report on the shallow synthesis by low energy ion implantation of delta-layers of Ag nanocrystals in SiO{sub 2} at few nanometers under its free surface. Transmission electron microscopy observations, ballistic simulations, and reflectance measurements are coupled to define the conditions for which the synthesis is fully controlled and when, on the contrary, this control is lost. We show that low dose implantation leads to the formation of a well-defined single plane of nanocrystals, while for larger doses, sputtering and diffusion effects limit the control of the size, position, and volume amount of these nanocrystals. This paper provides the experimental evidence of the incorporated dose saturation predicted in the literature when implanting metal ions at high doses in glass matrices. Its consequences on the particle population and the plasmonic optical response of the composite layers are carefully analyzed. We show here that this saturation phenomenon is underestimated in standard simulation predictions due to diffusion of metal atoms towards the surface and nanocrystal nucleation during the implantation process.

  8. Lithium Ion Batteries

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lithium ion batteries, which use a new battery chemistry, are being developed under cooperative agreements between Lockheed Martin, Ultralife Battery, and the NASA Lewis Research Center. The unit cells are made in flat (prismatic) shapes that can be connected in series and parallel to achieve desired voltages and capacities. These batteries will soon be marketed to commercial original-equipment manufacturers and thereafter will be available for military and space use. Current NiCd batteries offer about 35 W-hr/kg compared with 110 W-hr/kg for current lithium ion batteries. Our ultimate target for these batteries is 200 W-hr/kg.

  9. Pumped lithium loop test to evaluate advanced refractory metal alloys and simulated nuclear fuel elements

    NASA Technical Reports Server (NTRS)

    Brandenburf, G. P.; Hoffman, E. E.; Smith, J. P.

    1974-01-01

    The performance was determined of refractory metal alloys and uranium nitride fuel element specimens in flowing 1900F (1083C) lithium. The results demonstrate the suitability of the selected materials to perform satisfactorily from a chemical compatibility standpoint.

  10. 77 FR 28259 - Mailings of Lithium Batteries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... for mailpieces containing lithium metal or lithium-ion cells or batteries and applies regardless of...'' instead of ``lithium content'' for secondary lithium-ion batteries when describing maximum quantity limits...-ion (Rechargeable) Cells and Batteries Small consumer-type lithium-ion cells and batteries like...

  11. Diagnostics for liquid lithium experiments in CDX-U

    SciTech Connect

    Kaita, R.; Efthimion, P.; Hoffman, D.; Jones, B.; Kugel, H.; Majeski, R.; Munsat, T.; Raftopoulos, S.; Taylor, G.; Timberlake, J.

    2001-01-01

    A flowing liquid lithium first wall or divertor target could virtually eliminate the concerns with power density and erosion, tritium retention, and cooling associated with solid walls in fusion reactors. To investigate the interaction of a spherical torus plasma with liquid lithium limiters, large area divertor targets, and walls, discharges will be established in the Current Drive Experiment-Upgrade (CDX-U) where the plasma--wall interactions are dominated by liquid lithium surfaces. Among the unique CDX-U lithium diagnostics is a multilayer mirror (MLM) array, which will monitor the 13.5 nm LiIII line for core lithium concentrations. Additional spectroscopic diagnostics include a grazing incidence extreme ultraviolet (XUV) spectrometer (STRS) and a filterscope system to monitor D{sub {alpha}} and various impurity lines local to the lithium limiter. Profile data will be obtained with a multichannel tangential bolometer and a multipoint Thomson scattering system configured to give enhanced edge resolution. Coupons on the inner wall of the CDX-U vacuum vessel will be used for surface analysis. A 10000 frame per second fast visible camera and an IR camera will also be available.

  12. Diagnostics for liquid lithium experiments in CDX-U

    SciTech Connect

    R. Kaita; P. Efthimion; D. Hoffman; B. Jones; H. Kugel; R. Majeski; T. Munsat; S. Raftopoulos; G. Taylor; J. Timberlake; V. Soukhanovskii; D. Stutman; M. Iovea; M. Finkenthal; R. Doerner; S. Luckhardt; R. Maingi; R. Causey

    2000-06-21

    A flowing liquid lithium first wall or diverter target could virtually eliminate the concerns with power density and erosion, tritium retention, and cooling associated with solid walls in fusion reactors. To investigate the interaction of a spherical torus plasma with liquid lithium limiters, large area diverter targets, and walls, discharges will be established in the Current Drive Experiment-Upgrade (CDX-U) where the plasma-wall interactions are dominated by liquid lithium surfaces. Among the unique CDX-U lithium diagnostics is a multi-layer mirror (MLM) array, which will monitor the 135 {angstrom} LiIII line for core lithium concentrations. Additional spectroscopic diagnostics include a grazing incidence XUV spectrometer (STRS) and a filterscope system to monitor D{sub {alpha}} and various impurity lines local to the lithium limiter. Profile data will be obtained with a multichannel tangential bolometer and a multipoint Thomson scattering system configured to give enhanced edge resolution. Coupons on th e inner wall of the CDX-U vacuum vessel will be used for surface analysis. A 10,000 frame per second fast visible camera and an IR camera will also be available.

  13. Improvement of the free-surface tension model in shallow water basin by using in-situ bottom-friction measurements

    NASA Astrophysics Data System (ADS)

    Alekseenko, Elena; Kuznetsov, Konstantin; Roux, Bernard

    2016-04-01

    Wind stress on the free surface is the main driving force behind the circulation of the upper part of the ocean, which in hydrodynamic models are usually defined in terms of the coefficient of surface tension (Zhang et al., 2009, Davies et al., 2003). Moreover, wave motion impacts local currents and changes sea level, impacts the transport and the stratification of the entire water column. Influence of surface waves at the bottom currents is particularly pronounced in the shallow coastal systems. However, existing methods of parameterization of the surface tension have significant limits, especially in strong wind waves (Young et al., 2001, Jones et al., 2004) due to the difficulties of measuring the characteristics of surface waves in stormy conditions. Thus, the formula for calculating the coefficient of surface tension in our day is the actual problem in modeling fluid dynamics, particularly in the context of strong surface waves. In the hydrodynamic models usually a coefficient of surface tension is calculated once at the beginning of computation as a constant that depends on the averaged wind waves characteristic. Usually cases of strongly nonlinear wind waves are not taken into account, what significantly reduces the accuracy of the calculation of the flow structures and further calculation of the other processes in water basins, such as the spread of suspended matter and pollutants. Thus, wave motion influencing the pressure on the free surface and at the bottom must be considered in hydrodynamic models particularly in shallow coastal systems. A method of reconstruction of a free-surface drag coefficient based on the measured in-situ bottom pressure fluctuations is developed and applied in a three-dimensional hydrodynamic model MARS3D, developed by the French laboratory of IFREMER (IFREMER - French Research Institute for Marine Dynamics). MARS3D solves the Navier-Stokes equations for incompressible fluid in the Boussinesq approximation and with the

  14. Improvement of the free-surface tension model in shallow water basin by using in-situ bottom-friction measurements

    NASA Astrophysics Data System (ADS)

    Alekseenko, Elena; Kuznetsov, Konstantin; Roux, Bernard

    2016-04-01

    Wind stress on the free surface is the main driving force behind the circulation of the upper part of the ocean, which in hydrodynamic models are usually defined in terms of the coefficient of surface tension (Zhang et al., 2009, Davies et al., 2003). Moreover, wave motion impacts local currents and changes sea level, impacts the transport and the stratification of the entire water column. Influence of surface waves at the bottom currents is particularly pronounced in the shallow coastal systems. However, existing methods of parameterization of the surface tension have significant limits, especially in strong wind waves (Young et al., 2001, Jones et al., 2004) due to the difficulties of measuring the characteristics of surface waves in stormy conditions. Thus, the formula for calculating the coefficient of surface tension in our day is the actual problem in modeling fluid dynamics, particularly in the context of strong surface waves. In the hydrodynamic models usually a coefficient of surface tension is calculated once at the beginning of computation as a constant that depends on the averaged wind waves characteristic. Usually cases of strongly nonlinear wind waves are not taken into account, what significantly reduces the accuracy of the calculation of the flow structures and further calculation of the other processes in water basins, such as the spread of suspended matter and pollutants. Thus, wave motion influencing the pressure on the free surface and at the bottom must be considered in hydrodynamic models particularly in shallow coastal systems. A method of reconstruction of a free-surface drag coefficient based on the measured in-situ bottom pressure fluctuations is developed and applied in a three-dimensional hydrodynamic model MARS3D, developed by the French laboratory of IFREMER (IFREMER - French Research Institute for Marine Dynamics). MARS3D solves the Navier-Stokes equations for incompressible fluid in the Boussinesq approximation and with the

  15. Lithium disulfide battery

    DOEpatents

    Kaun, Thomas D.

    1988-01-01

    A negative electrode limited secondary electrochemical cell having dense FeS.sub.2 positive electrode operating exclusively on the upper plateau, a Li alloy negative electrode and a suitable lithium-containing electrolyte. The electrolyte preferably is 25 mole percent LiCl, 38 mole percent LiBr and 37 mole percent KBr. The cell may be operated isothermally.

  16. Lithium battery discharge tests

    NASA Technical Reports Server (NTRS)

    Johnson, C. J.

    1980-01-01

    The long term discharge of a variety of lithium cells was characterized and the susceptibility of the cells to chemical variation during the slow discharge was tested. A shunt resistor was set across the terminals to monitor the voltage as a function of time. Failures were identified by premature voltage drops.

  17. Lithium ion conducting electrolytes

    DOEpatents

    Angell, C. Austen; Liu, Changle

    1996-01-01

    A liquid, predominantly lithium-conducting, ionic electrolyte having exceptionally high conductivity at temperatures of 100.degree. C. or lower, including room temperature, and comprising the lithium salts selected from the group consisting of the thiocyanate, iodide, bromide, chloride, perchlorate, acetate, tetrafluoroborate, perfluoromethane sulfonate, perfluoromethane sulfonamide, tetrahaloaluminate, and heptahaloaluminate salts of lithium, with or without a magnesium-salt selected from the group consisting of the perchlorate and acetate salts of magnesium. Certain of the latter embodiments may also contain molecular additives from the group of acetonitrile (CH.sub.3 CN) succinnonitrile (CH.sub.2 CN).sub.2, and tetraglyme (CH.sub.3 --O--CH.sub.2 --CH.sub.2 --O--).sub.2 (or like solvents) solvated to a Mg.sup.+2 cation to lower the freezing point of the electrolyte below room temperature. Other particularly useful embodiments contain up to about 40, but preferably not more than about 25, mol percent of a long chain polyether polymer dissolved in the lithium salts to provide an elastic or rubbery solid electrolyte of high ambient temperature conductivity and exceptional 100.degree. C. conductivity. Another embodiment contains up to about but not more than 10 mol percent of a molecular solvent such as acetone.

  18. Lithium ion conducting electrolytes

    DOEpatents

    Angell, C.A.; Liu, C.

    1996-04-09

    A liquid, predominantly lithium-conducting, ionic electrolyte is described having exceptionally high conductivity at temperatures of 100 C or lower, including room temperature, and comprising the lithium salts selected from the group consisting of the thiocyanate, iodide, bromide, chloride, perchlorate, acetate, tetrafluoroborate, perfluoromethane sulfonate, perfluoromethane sulfonamide, tetrahaloaluminate, and heptahaloaluminate salts of lithium, with or without a magnesium-salt selected from the group consisting of the perchlorate and acetate salts of magnesium. Certain of the latter embodiments may also contain molecular additives from the group of acetonitrile (CH{sub 3}CN), succinnonitrile (CH{sub 2}CN){sub 2}, and tetraglyme (CH{sub 3}--O--CH{sub 2}--CH{sub 2}--O--){sub 2} (or like solvents) solvated to a Mg{sup +2} cation to lower the freezing point of the electrolyte below room temperature. Other particularly useful embodiments contain up to about 40, but preferably not more than about 25, mol percent of a long chain polyether polymer dissolved in the lithium salts to provide an elastic or rubbery solid electrolyte of high ambient temperature conductivity and exceptional 100 C conductivity. Another embodiment contains up to about but not more than 10 mol percent of a molecular solvent such as acetone. 2 figs.

  19. Low Energy Sputtering Events at Free Surfaces near Anti-Phase and Grain Boundaries in Ni3Al

    SciTech Connect

    Gao, Fei; Bacon, David J.; Lai, Wenshen; Kurtz, Richard J.

    2006-09-21

    Atomic recoil events on free surfaces orthogonal to two different anti-phase boundaries (APBs) and two grain boundaries (GBs) in Ni3Al are simulated using molecular dynamics methods. The threshold energy for sputtering, Esp, and adatom creation, Ead, are determined as a function of recoil direction. The study is relevant to FEG STEM experiments on preferential Al sputtering and/or enhancement of the Ni-Al ratio near boundaries. Surfaces intersected by {l_brace}110{r_brace} and {l_brace}111{r_brace} APBs have minimum Esp of 6.5 eV for an Al atom on the Ni-Al mixed (M) surface, which is close to the value of 6.0 eV for a perfect M surface. High values of Esp of an Al atom generally occur at large angle to the surface normal and depend strongly on the detailed atomic configuration of the surface. The mean Esp averaged over all recoil directions reveals that APBs have a small effect on the threshold sputtering. However, the results for Ead imply that an electron beam could create more Al adatoms on surfaces intersected by APBs than on those without. The equilibrium, minimum energy structures for a (001) surface intersected by either Sigma5[001](210) or Sigma25[001](340) symmetric tilt grain boundaries are computed. Esp for surface Al atoms near these GBs increases monotonically with increasing recoil angle to the surface normal, with a minimum value which is only about 1 eV different from that obtained for a perfect surface. Temperature up to 300 K has no effect on this result. It is concluded that the experimental observations of preferential sputtering are due to effects beyond those for Esp studied here. Possible reasons for this are discussed.

  20. Generation of inhomogeneous bulk plane acoustic modes by laser-induced thermoelastic grating near mechanically free surface

    SciTech Connect

    Gusev, Vitalyi

    2010-06-15

    The detailed theoretical description of how picosecond plane shear acoustic transients can be excited by ultrafast lasers in isotropic media is presented. The processes leading to excitation of inhomogeneous plane bulk compression/dilatation (c/d) and shear acoustic modes by transient laser interference pattern at a mechanically free surface of an elastically isotropic medium are analyzed. Both pure modes are dispersive. The modes can be evanescent or propagating. The mechanical displacement vector in both propagating modes is oriented obliquely to the mode propagation direction. Consequently the c/d mode is not purely longitudinal and shear mode is not purely transversal. Each of the propagating modes has a plane wave front parallel to the surface and the amplitude harmonically modulated along the surface. Inhomogeneous shear acoustic mode cannot be generated in isotropic medium by thermal expansion and is excited by mode conversion of laser-generated inhomogeneous c/d acoustic mode incident on the surface. The spectral transformation function of the laser radiation conversion into shear modes has one of its maxima at a frequency corresponding to transmission from laser-induced generation of propagating to laser-induced generation of evanescent c/d modes. At this particular frequency the shear waves are due to their Cherenkov emission by bulk longitudinal acoustic waves skimming along the laser-irradiated surface, which are generated by laser-induced gratings synchronously. There exists an interval of frequencies where only shear acoustic modes are launched in the material by laser-induced grating, while c/d modes generated by thermoelastic optoacoustic conversion are evanescent. Propagating picosecond plane shear acoustic fronts excited by interference pattern of fs-ps laser pulses can be applied for the determination of the shear rigidity by optoacoustic echoes diagnostics of thin films and coatings. Theoretical predictions are correlated with available results

  1. Sputter deposition of lithium silicate - lithium phosphate amorphous electrolytes

    SciTech Connect

    Dudney, N.J.; Bates, J.B.; Luck, C.F. ); Robertson, J.D. . Dept. of Chemistry)

    1991-01-01

    Thin films of an amorphous lithium-conducting electrolyte were deposited by rf magnetron sputtering of ceramic targets containing Li{sub 4}SiO{sub 4} and Li{sub 3}PO{sub 4}. The lithium content of the films was found to depend more strongly on the nature and composition of the targets than on many other sputtering parameters. For targets containing Li{sub 4}SiO{sub 4}, most of the lithium was found to segregate away from the sputtered area of the target. Codeposition using two sputter sources achieves a high lithium content in a controlled and reproducible film growth. 10 refs., 4 figs.

  2. Experimental lithium system. Final report

    SciTech Connect

    Kolowith, R.; Berg, J.D.; Miller, W.C.

    1985-04-01

    A full-scale mockup of the Fusion Materials Irradiation Test (FMIT) Facility lithium system was built at the Hanford Engineering Development Laboratory (HEDL). This isothermal mockup, called the Experimental Lithium System (ELS), was prototypic of FMIT, excluding the accelerator and dump heat exchanger. This 3.8 m/sup 3/ lithium test loop achieved over 16,000 hours of safe and reliable operation. An extensive test program demonstrated satisfactory performance of the system components, including the HEDL-supplied electromagnetic lithium pump, the lithium jet target, the purification and characterization hardware, as well as the auxiliary argon and vacuum systems. Experience with the test loop provided important information on system operation, performance, and reliability. This report presents a complete overview of the entire Experimental Lithium System test program and also includes a summary of such areas as instrumentation, coolant chemistry, vapor/aerosol transport, and corrosion.

  3. Membranes in Lithium Ion Batteries

    PubMed Central

    Yang, Min; Hou, Junbo

    2012-01-01

    Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed. PMID:24958286

  4. Computation of turbulent flow in a thin liquid layer of fluid involving a hydraulic jump

    NASA Technical Reports Server (NTRS)

    Rahman, M. M.; Faghri, A.; Hankey, W. L.

    1991-01-01

    Numerically computed flow fields and free surface height distributions are presented for the flow of a thin layer of liquid adjacent to a solid horizontal surface that encounters a hydraulic jump. Two kinds of flow configurations are considered: two-dimensional plane flow and axisymmetric radial flow. The computations used a boundary-fitted moving grid method with a k-epsilon model for the closure of turbulence. The free surface height was determined by an optimization procedure which minimized the error in the pressure distribution on the free surface. It was also checked against an approximate procedure involving integration of the governing equations and use of the MacCormack predictor-corrector method. The computed film height also compared reasonably well with previous experiments. A region of recirculating flow was found to be present adjacent to the solid boundary near the location of the jump, which was caused by a rapid deceleration of the flow.

  5. Rat brain and serum lithium concentrations after acute injections of lithium carbonate and orotate.

    PubMed

    Kling, M A; Manowitz, P; Pollack, I W

    1978-06-01

    Eight hours after intraperitoneal injections of 1.0, 2.0, and 4.0m equiv Li kg-1, the serum and brain lithium concentrations of rats were significantly greater after lithium orotate than after lithium carbonate. While little serum lithium remained at 24 h after injection of 2.0 m equiv kg-1 lithium carbonate, two-thirds of the 2 h serum lithium concentration was present 24h after lithium orotate. Furthermore, the 24 h brain concentration of lithium after lithium orotate was approximately three times greater than that after lithium carbonate. These data suggest the possibility that lower doses of lithium orotate than lithium carbonate may achieve therapeutic brain lithium concentrations and relatively stable serum concentrations. PMID:26768

  6. Solid lithium-ion electrolyte

    SciTech Connect

    Zhang, J.G.; Benson, D.K.; Tracy, C.E.

    1998-02-10

    The present invention relates to the composition of a solid lithium-ion electrolyte based on the Li{sub 2}O--CeO{sub 2}--SiO{sub 2} system having good transparent characteristics and high ion conductivity suitable for uses in lithium batteries, electrochromic devices and other electrochemical applications. 12 figs.

  7. Solid lithium-ion electrolyte

    DOEpatents

    Zhang, Ji-Guang; Benson, David K.; Tracy, C. Edwin

    1998-01-01

    The present invention relates to the composition of a solid lithium-ion electrolyte based on the Li.sub.2 O--CeO.sub.2 --SiO.sub.2 system having good transparent characteristics and high ion conductivity suitable for uses in lithium batteries, electrochromic devices and other electrochemical applications.

  8. Lithium/bromine cell systems

    SciTech Connect

    Howard, W.G.; Skarstad, P.M.; Hayes, T.G.; Owens, B.B.

    1980-01-01

    Bromine is attractive as a cathode material because cells with a high energy density and high cell voltage are theoretically possible. The addition of small amounts of certain salts or organic compounds results in bromine solutions of sufficient conductivity for cathode applications. However, given these highly conductive bromine cathodes, lithium/bromine cells are limited in rate and practical available capacity by the high resistivity of the discharge product. The rate of resistance increase for the best bromine cells in this study is more than one order of magnitude greater than that observed for corresponding lithium/iodine cells. Lithium/bromine cells can function at pacemaker rates and they may be superior to cells used in early pacemakers. However, the authors have not found the lithium/bromine cells described to be superior to existing lithium/iodine cells available for cardiac pacemakers. 17 refs.

  9. HOW RELIABLE IS 24 HOUR SERUM LITHIUM LEVEL AFTER A TEST DOSE OF LITHIUM IN PREDICTING OPTIMAL LITHIUM DOSE?

    PubMed Central

    Kuruvilla, K.; Shaji, K.S.

    1989-01-01

    SUMMARY 57% of a group of 35 patients treated with Lithium Carbonate at dosages predicted by the nomogram suggested by Cooper et al (1973) failed to reach therapeutic levels of serum lithium. This finding casts serious doubts on the usefulness of the claim by Cooper et al (1973 & 1976) that 24 hour serum lithium level after a test dose of 600 mg. lithium can predict the daily lithium dose. PMID:21927360

  10. Blockage effects on the hydrodynamic performance of a marine cross-flow turbine.

    PubMed

    Consul, Claudio A; Willden, Richard H J; McIntosh, Simon C

    2013-02-28

    This paper explores the influence of blockage and free-surface deformation on the hydrodynamic performance of a generic marine cross-flow turbine. Flows through a three-bladed turbine with solidity 0.125 are simulated at field-test blade Reynolds numbers, O(10(5)-10(6)), for three different cross-stream blockages: 12.5, 25 and 50 per cent. Two representations of the free-surface boundary are considered: rigid lid and deformable free surface. Increasing the blockage is observed to lead to substantial increases in the power coefficient; the highest power coefficient computed is 1.23. Only small differences are observed between the two free-surface representations, with the deforming free-surface turbine out-performing the rigid lid turbine by 6.7 per cent in power at the highest blockage considered. This difference is attributed to the increase in effective blockage owing to the deformation of the free surface. Hydrodynamic efficiency, the ratio of useful power generated to overall power removed from the flow, is found to increase with blockage, which is consistent with the presence of a higher flow velocity through the core of the turbine at higher blockage ratios. Froude number is found to have little effect on thrust and power coefficients, but significant influence on surface elevation drop across the turbine.

  11. Lithium orotate, carbonate and chloride: pharmacokinetics, polyuria in rats.

    PubMed Central

    Smith, D F

    1976-01-01

    1 The pharmacokinetics of the lithium ion administered as lithium orotate were studied in rats. Parallel studies were carried out with lithium carbonate and lithium chloride. 2 No differences in the uptake, distribution and excretion of the lithium ion were observed between lithium orotate, lithium carbonate and lithium chloride after single intraperitoneal, subcutaneous or intragastric injections (0.5-1.0 mEq lithium/kg) or after administration of the lithium salts for 20 days in the food. 3 The findings oppose the notion that the pharmacokinetics of the lithium ion given as lithium orotate differ from lithium chloride or lithium carbonate. 4 Polyuria and polydipsia developed more slowly in rats given lithium orotate than in those given lithium carbonate or lithium chloride, perhaps due to an effect of the orotate anion. PMID:1260219

  12. Lithium orotate, carbonate and chloride: pharmacokinetics, polyuria in rats.

    PubMed

    Smith, D F

    1976-04-01

    1 The pharmacokinetics of the lithium ion administered as lithium orotate were studied in rats. Parallel studies were carried out with lithium carbonate and lithium chloride. 2 No differences in the uptake, distribution and excretion of the lithium ion were observed between lithium orotate, lithium carbonate and lithium chloride after single intraperitoneal, subcutaneous or intragastric injections (0.5-1.0 mEq lithium/kg) or after administration of the lithium salts for 20 days in the food. 3 The findings oppose the notion that the pharmacokinetics of the lithium ion given as lithium orotate differ from lithium chloride or lithium carbonate. 4 Polyuria and polydipsia developed more slowly in rats given lithium orotate than in those given lithium carbonate or lithium chloride, perhaps due to an effect of the orotate anion. PMID:1260219

  13. Evaluation of tantalum-alloy-clad uranium mononitride fuel specimens from 7500-hour, 1040 C pumped-lithium-loop test

    NASA Technical Reports Server (NTRS)

    Watson, G. K.

    1974-01-01

    Simulated nuclear fuel element specimens, consisting of uranium mononitride (UN) fuel cylinders clad with tungsten-lined T-111, were exposed for up to 7500 hr at 1040 C (1900 F) in a pumped-lithium loop. The lithium flow velocity was 1.5 m/sec (5 ft/sec) in the specimen test section. No evidence of any compatibility problems between the specimens and the flowing lithium was found based on appearance, weight change, chemistry, and metallography. Direct exposure of the UN to the lithium through a simulated cladding crack resulted in some erosion of the UN in the area of the defect. The T-111 cladding was ductile after lithium exposure, but it was sensitive to hydrogen embrittlement during post-test handling.

  14. Thermocapillary flow on superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Baier, Tobias; Steffes, Clarissa; Hardt, Steffen

    2010-09-01

    A liquid in Cassie-Baxter state above a structured superhydrophobic surface is ideally suited for surface driven transport due to its large free surface fraction in close contact to a solid. We investigate thermal Marangoni flow over a superhydrophobic array of fins oriented parallel or perpendicular to an applied temperature gradient. In the Stokes limit we derive an analytical expression for the bulk flow velocity above the surface and compare it with numerical solutions of the Navier-Stokes equation. Even for moderate temperature gradients comparatively large flow velocities are induced, suggesting to utilize this principle for microfluidic pumping.

  15. Effects of dynamically variable saturation and matrix-conduit coupling of flow in karst aquifers

    USGS Publications Warehouse

    Reimann, T.; Geyer, T.; Shoemaker, W.B.; Liedl, R.; Sauter, M.

    2011-01-01

    Well-developed karst aquifers consist of highly conductive conduits and a relatively low permeability fractured and/or porous rock matrix and therefore behave as a dual-hydraulic system. Groundwater flow within highly permeable strata is rapid and transient and depends on local flow conditions, i.e., pressurized or nonpressurized flow. The characterization of karst aquifers is a necessary and challenging task because information about hydraulic and spatial conduit properties is poorly defined or unknown. To investigate karst aquifers, hydraulic stresses such as large recharge events can be simulated with hybrid (coupled discrete continuum) models. Since existing hybrid models are simplifications of the system dynamics, a new karst model (ModBraC) is presented that accounts for unsteady and nonuniform discrete flow in variably saturated conduits employing the Saint-Venant equations. Model performance tests indicate that ModBraC is able to simulate (1) unsteady and nonuniform flow in variably filled conduits, (2) draining and refilling of conduits with stable transition between free-surface and pressurized flow and correct storage representation, (3) water exchange between matrix and variably filled conduits, and (4) discharge routing through branched and intermeshed conduit networks. Subsequently, ModBraC is applied to an idealized catchment to investigate the significance of free-surface flow representation. A parameter study is conducted with two different initial conditions: (1) pressurized flow and (2) free-surface flow. If free-surface flow prevails, the systems is characterized by (1) a time lag for signal transmission, (2) a typical spring discharge pattern representing the transition from pressurized to free-surface flow, and (3) a reduced conduit-matrix interaction during free-surface flow. Copyright 2011 by the American Geophysical Union.

  16. Critical Velocity in Open Capillary Channel Flows

    NASA Technical Reports Server (NTRS)

    Rosendahl, Uwe; Dreyer, Michael E.; Rath, Hans J.; Motil, Brian; Singh, Bhim S. (Technical Monitor)

    2001-01-01

    We investigate forced liquid flows through open capillary channels with free surfaces experimentally. The experiments were performed under low gravity conditions in the Bremen Drop Tower and on board the sounding rocket TEXUS-37. Open capillary channels (vanes) are used in surface tension tanks to transport the propellant and to provide a flow path for the bubble-free liquid supply to the thrusters. Since the free surfaces can only withstand a certain pressure differential between the liquid and ambient, the flow rate in the channel is limited. The maximum flow rate is achieved when the surfaces collapse and gas is ingested into the outlet. Since experimental and theoretical data of this flow rate limitation is lacking, the safety factors for the application of vanes in surface tension tanks must be unnecessary high. The aim of the investigation is to determine the maximum liquid flow rate and the corresponding critical flow velocity. The characteristic nondimensional parameters, OHNESORGE number, and gap ratio, cover a wide range of usual vanes. For the theoretical approach a one-dimensional momentum balance was set up. The numerical solution yields the maximum volume flux and the position of the free surface in good agreement with the experiments.

  17. Lithium niobate explosion monitor

    DOEpatents

    Bundy, Charles H.; Graham, Robert A.; Kuehn, Stephen F.; Precit, Richard R.; Rogers, Michael S.

    1990-01-01

    Monitoring explosive devices is accomplished with a substantially z-cut lithium niobate crystal in abutment with the explosive device. Upon impact by a shock wave from detonation of the explosive device, the crystal emits a current pulse prior to destruction of the crystal. The current pulse is detected by a current viewing transformer and recorded as a function of time in nanoseconds. In order to self-check the crystal, the crystal has a chromium film resistor deposited thereon which may be heated by a current pulse prior to detonation. This generates a charge which is detected by a charge amplifier.

  18. Glycine lithium nitrate crystals

    NASA Astrophysics Data System (ADS)

    González-Valenzuela, R.; Hernández-Paredes, J.; Medrano-Pesqueira, T.; Esparza-Ponce, H. E.; Jesús-Castillo, S.; Rodriguez-Mijangos, R.; Terpugov, V. S.; Alvarez-Ramos, M. E.; Duarte-Möller, A.

    Crystals of glycine lithium nitrate with non-linear optical properties have been grown in a solution by slow evaporation at room temperature. The crystal shows a good thermal stability from room temperature to 175 °C where the crystal begins to degrade. This property is desirable for future technological applications. Also, a good performance on the second harmonic generation was found, characterizing the emitted dominant wavelength by a customized indirect procedure using luminance and chromaticity measured data based on the CIE-1931 standard. Additionally, the 532 nm signal was detected by using a variant to the Kurtz and Perry method.

  19. Halo Star Lithium Depletion

    SciTech Connect

    Pinsonneault, M. H.; Walker, T. P.; Steigman, G.; Narayanan, Vijay K.

    1999-12-10

    The depletion of lithium during the pre-main-sequence and main-sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. Previous work has indicated a wide range of possible depletion factors, ranging from minimal in standard (nonrotating) stellar models to as much as an order of magnitude in models that include rotational mixing. Recent progress in the study of the angular momentum evolution of low-mass stars permits the construction of theoretical models capable of reproducing the angular momentum evolution of low-mass open cluster stars. The distribution of initial angular momenta can be inferred from stellar rotation data in young open clusters. In this paper we report on the application of these models to the study of lithium depletion in main-sequence halo stars. A range of initial angular momenta produces a range of lithium depletion factors on the main sequence. Using the distribution of initial conditions inferred from young open clusters leads to a well-defined halo lithium plateau with modest scatter and a small population of outliers. The mass-dependent angular momentum loss law inferred from open cluster studies produces a nearly flat plateau, unlike previous models that exhibited a downward curvature for hotter temperatures in the 7Li-Teff plane. The overall depletion factor for the plateau stars is sensitive primarily to the solar initial angular momentum used in the calibration for the mixing diffusion coefficients. Uncertainties remain in the treatment of the internal angular momentum transport in the models, and the potential impact of these uncertainties on our results is discussed. The 6Li/7Li depletion ratio is also examined. We find that the dispersion in the plateau and the 6Li/7Li depletion ratio scale with the absolute 7Li depletion in the plateau, and we use observational data to set bounds on the 7Li depletion in main-sequence halo

  20. Lithium niobate explosion monitor

    DOEpatents

    Bundy, C.H.; Graham, R.A.; Kuehn, S.F.; Precit, R.R.; Rogers, M.S.

    1990-01-09

    Monitoring explosive devices is accomplished with a substantially z-cut lithium niobate crystal in abutment with the explosive device. Upon impact by a shock wave from detonation of the explosive device, the crystal emits a current pulse prior to destruction of the crystal. The current pulse is detected by a current viewing transformer and recorded as a function of time in nanoseconds. In order to self-check the crystal, the crystal has a chromium film resistor deposited thereon which may be heated by a current pulse prior to detonation. This generates a charge which is detected by a charge amplifier. 8 figs.

  1. Lithium electric dipole polarizability

    SciTech Connect

    Puchalski, M.; KePdziera, D.; Pachucki, K.

    2011-11-15

    The electric dipole polarizability of the lithium atom in the ground state is calculated including relativistic and quantum electrodynamics corrections. The obtained result {alpha}{sub E}=164.0740(5) a.u. is in good agreement with the less accurate experimental value of 164.19(1.08) a.u. The small uncertainty of about 3 parts per 10{sup 6} comes from the approximate treatment of quantum electrodynamics corrections. Our theoretical result can be considered as a benchmark for more general atomic structure methods and may serve as a reference value for the relative measurement of polarizabilities of the other alkali-metal atoms.

  2. Effect of evaporation or infiltration on the free surface of groundwater in certain problems of underground hydromechanics

    NASA Astrophysics Data System (ADS)

    Bereslavskii, E. N.

    2016-06-01

    Within the framework of the theory of plane steady filtration of an incompressible fluid according to Darcy's law, two limiting schemes modeling the filtration flows under the Joukowski tongue through a soil massif spread over an impermeable foundation or strongly permeable confined water-bearing horizon are considered.

  3. Method of recycling lithium borate to lithium borohydride through methyl borate

    DOEpatents

    Filby, Evan E.

    1977-01-01

    This invention provides a method for the recycling of lithium borate to lithium borohydride which can be reacted with water to generate hydrogen for utilization as a fuel. The lithium borate by-product of the hydrogen generation reaction is reacted with hydrogen chloride and water to produce boric acid and lithium chloride. The boric acid and lithium chloride are converted to lithium borohydride through a methyl borate intermediate to complete the recycle scheme.

  4. A lithium superionic conductor.

    PubMed

    Kamaya, Noriaki; Homma, Kenji; Yamakawa, Yuichiro; Hirayama, Masaaki; Kanno, Ryoji; Yonemura, Masao; Kamiyama, Takashi; Kato, Yuki; Hama, Shigenori; Kawamoto, Koji; Mitsui, Akio

    2011-09-01

    Batteries are a key technology in modern society. They are used to power electric and hybrid electric vehicles and to store wind and solar energy in smart grids. Electrochemical devices with high energy and power densities can currently be powered only by batteries with organic liquid electrolytes. However, such batteries require relatively stringent safety precautions, making large-scale systems very complicated and expensive. The application of solid electrolytes is currently limited because they attain practically useful conductivities (10(-2) S cm(-1)) only at 50-80 °C, which is one order of magnitude lower than those of organic liquid electrolytes. Here, we report a lithium superionic conductor, Li(10)GeP(2)S(12) that has a new three-dimensional framework structure. It exhibits an extremely high lithium ionic conductivity of 12 mS cm(-1) at room temperature. This represents the highest conductivity achieved in a solid electrolyte, exceeding even those of liquid organic electrolytes. This new solid-state battery electrolyte has many advantages in terms of device fabrication (facile shaping, patterning and integration), stability (non-volatile), safety (non-explosive) and excellent electrochemical properties (high conductivity and wide potential window). PMID:21804556

  5. A lithium superionic conductor.

    PubMed

    Kamaya, Noriaki; Homma, Kenji; Yamakawa, Yuichiro; Hirayama, Masaaki; Kanno, Ryoji; Yonemura, Masao; Kamiyama, Takashi; Kato, Yuki; Hama, Shigenori; Kawamoto, Koji; Mitsui, Akio

    2011-09-01

    Batteries are a key technology in modern society. They are used to power electric and hybrid electric vehicles and to store wind and solar energy in smart grids. Electrochemical devices with high energy and power densities can currently be powered only by batteries with organic liquid electrolytes. However, such batteries require relatively stringent safety precautions, making large-scale systems very complicated and expensive. The application of solid electrolytes is currently limited because they attain practically useful conductivities (10(-2) S cm(-1)) only at 50-80 °C, which is one order of magnitude lower than those of organic liquid electrolytes. Here, we report a lithium superionic conductor, Li(10)GeP(2)S(12) that has a new three-dimensional framework structure. It exhibits an extremely high lithium ionic conductivity of 12 mS cm(-1) at room temperature. This represents the highest conductivity achieved in a solid electrolyte, exceeding even those of liquid organic electrolytes. This new solid-state battery electrolyte has many advantages in terms of device fabrication (facile shaping, patterning and integration), stability (non-volatile), safety (non-explosive) and excellent electrochemical properties (high conductivity and wide potential window).

  6. Anodes for rechargeable lithium batteries

    DOEpatents

    Thackeray, Michael M.; Kepler, Keith D.; Vaughey, John T.

    2003-01-01

    A negative electrode (12) for a non-aqueous electrochemical cell (10) with an intermetallic host structure containing two or more elements selected from the metal elements and silicon, capable of accommodating lithium within its crystallographic host structure such that when the host structure is lithiated it transforms to a lithiated zinc-blende-type structure. Both active elements (alloying with lithium) and inactive elements (non-alloying with lithium) are disclosed. Electrochemical cells and batteries as well as methods of making the negative electrode are disclosed.

  7. Lithium ion conducting ionic electrolytes

    DOEpatents

    Angell, C. Austen; Xu, Kang; Liu, Changle

    1996-01-01

    A liquid, predominantly lithium-conducting, ionic electrolyte is described which has exceptionally high conductivity at temperatures of 100.degree. C. or lower, including room temperature. It comprises molten lithium salts or salt mixtures in which a small amount of an anionic polymer lithium salt is dissolved to stabilize the liquid against recrystallization. Further, a liquid ionic electrolyte which has been rubberized by addition of an extra proportion of anionic polymer, and which has good chemical and electrochemical stability, is described. This presents an attractive alternative to conventional salt-in-polymer electrolytes which are not cationic conductors.

  8. Lithium ion conducting ionic electrolytes

    DOEpatents

    Angell, C.A.; Xu, K.; Liu, C.

    1996-01-16

    A liquid, predominantly lithium-conducting, ionic electrolyte is described which has exceptionally high conductivity at temperatures of 100 C or lower, including room temperature. It comprises molten lithium salts or salt mixtures in which a small amount of an anionic polymer lithium salt is dissolved to stabilize the liquid against recrystallization. Further, a liquid ionic electrolyte which has been rubberized by addition of an extra proportion of anionic polymer, and which has good chemical and electrochemical stability, is described. This presents an attractive alternative to conventional salt-in-polymer electrolytes which are not cationic conductors. 4 figs.

  9. Solvability of Initial-Boundary Value Problems for Euler's Equations for Flows of AN Ideal Incompressible Nonhomogeneous Fluid and AN Ideal Barotropic Fluid Bounded by Free Surfaces

    NASA Astrophysics Data System (ADS)

    Sedenko, V. I.

    1995-02-01

    The Nishida version of the abstract nonlinear Cauchy-Kovalevskaya theorem is used to obtain the results indicated in the title. In this connection, one has to construct special scales of Banach spaces and to estimate in them the solutions of elliptic equations.Bibliography: 16 titles.

  10. A Lithium Superionic Sulfide Cathode for Lithium-Sulfur Batteries

    SciTech Connect

    Lin, Zhan; Liu, Zengcai; Dudney, Nancy J; Liang, Chengdu

    2013-01-01

    This work presents a facile synthesis approach for core-shell structured Li2S nanoparticles, which have Li2S as the core and Li3PS4 as the shell. This material functions as lithium superionic sulfide (LSS) cathode for long-lasting, energy-efficient lithium-sulfur (Li-S) batteries. The LSS has an ionic conductivity of 10-7 S cm-1 at 25 oC, which is 6 orders of magnitude higher than that of bulk Li2S (~10-13 S cm-1). The high lithium-ion conductivity of LSS imparts an excellent cycling performance to all-solid Li-S batteries, which also promises safe cycling of high-energy batteries with metallic lithium anodes.

  11. The relation between shock-state particle velocity and free surface velocity: A molecular dynamics study on single crystal Cu and silica glass

    NASA Astrophysics Data System (ADS)

    Luo, Sheng-Nian; Han, Li-Bo; Xie, Yun; An, Qi; Zheng, Lianqing; Xia, Kaiwen

    2008-05-01

    We investigate the ratio Rrp of the free surface velocity to the shock-state particle velocity during shock wave loading with molecular dynamics simulations on two representative solids, single crystal Cu, and silica glass. The free surface velocity is obtained as a function of the particle velocity behind the shock front (or shock stress) for loading on Cu along ⟨100⟩, ⟨110⟩, and ⟨111⟩, and on the isotropic glass. Rrp≥1 for Cu and Rrp<1 for silica glass, and it increases with shock strength; the simulations agree well with the experimental results. For supported shock loading of silica glass at 30-90 GPa, the SiIV-SiVI transition occurs upon shock, inducing substantial densification and thus small Rrp (0.65-0.78). For single crystal Cu, Rrp deviates from 1 near the Hugoniot elastic limit and reaches ˜1.2 at 355 GPa for ⟨100⟩ shock. Rrp is anisotropic, e.g., it is about 1.02, 1.08, and 1.06 for shock loading to about 80 GPa along ⟨100⟩, ⟨110⟩, and ⟨111⟩, respectively. Such an anisotropy is mostly due to that in the degree of stress relaxation at low pressures and that in solid state disordering at high pressures. These results suggest that Rrp is materials dependent and the assumption of Rrp=1 is only valid in a limited stress range. Caution should be exercised when interpreting the free surface velocity measurements as regards the shock states.

  12. Cyanoethylated Compounds as Additives in Lithium/Lithium Ion Batteries

    SciTech Connect

    Nagasubramanian, Ganesan

    1998-05-08

    The power loss of lithium/lithium ion battery cells is significantly reduced, especially at low temperatures, when about 1% by weight of an additive is incorporated in the electrolyte layer of the cells. The usable additives are organic solvent soluble cyanoethylated polysaccharides and poly(vinyl alcohol). The power loss decrease results primarily from the decrease in the charge transfer resistance at the interface between the electrolyte and the cathode.

  13. Cyanoethylated compounds as additives in lithium/lithium batteries

    DOEpatents

    Nagasubramanian, Ganesan

    1999-01-01

    The power loss of lithium/lithium ion battery cells is significantly reduced, especially at low temperatures, when about 1% by weight of an additive is incorporated in the electrolyte layer of the cells. The usable additives are organic solvent soluble cyanoethylated polysaccharides and poly(vinyl alcohol). The power loss decrease results primarily from the decrease in the charge transfer resistance at the interface between the electrolyte and the cathode.

  14. Lithium metal doped electrodes for lithium-ion rechargeable chemistry

    DOEpatents

    Liu, Gao; Battaglia, Vince; Wang, Lei

    2016-09-13

    An embodiment of the invention combines the superior performance of a polyvinylidene difluoride (PVDF) or polyethyleneoxide (POE) binder, the strong binding force of a styrene-butadiene (SBR) binder, and a source of lithium ions in the form of solid lithium metal powder (SLMP) to form an electrode system that has improved performance as compared to PVDF/SBR binder based electrodes. This invention will provide a new way to achieve improved results at a much reduced cost.

  15. Thermal Pollution Mathematical Model. Volume 6: Verification of Three-Dimensional Free-Surface Model at Anclote Anchorage. [environment impact of thermal discharges from power plants

    NASA Technical Reports Server (NTRS)

    Lee, S. S.; Sengupta, S.; Tuann, S. Y.; Lee, C. R.

    1980-01-01

    The free-surface model presented is for tidal estuaries and coastal regions where ambient tidal forces play an important role in the dispersal of heated water. The model is time dependent, three dimensional, and can handle irregular bottom topography. The vertical stretching coordinate is adopted for better treatment of kinematic condition at the water surface. The results include surface elevation, velocity, and temperature. The model was verified at the Anclote Anchorage site of Florida Power Company. Two data bases at four tidal stages for winter and summer conditions were used to verify the model. Differences between measured and predicted temperatures are on an average of less than 1 C.

  16. 21 CFR 862.3560 - Lithium test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Lithium test system. 862.3560 Section 862.3560....3560 Lithium test system. (a) Identification. A lithium test system is a device intended to measure lithium (from the drug lithium carbonate) in serum or plasma. Measurements of lithium are used to...

  17. 21 CFR 862.3560 - Lithium test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lithium test system. 862.3560 Section 862.3560....3560 Lithium test system. (a) Identification. A lithium test system is a device intended to measure lithium (from the drug lithium carbonate) in serum or plasma. Measurements of lithium are used to...

  18. 21 CFR 862.3560 - Lithium test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Lithium test system. 862.3560 Section 862.3560....3560 Lithium test system. (a) Identification. A lithium test system is a device intended to measure lithium (from the drug lithium carbonate) in serum or plasma. Measurements of lithium are used to...

  19. 21 CFR 862.3560 - Lithium test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Lithium test system. 862.3560 Section 862.3560....3560 Lithium test system. (a) Identification. A lithium test system is a device intended to measure lithium (from the drug lithium carbonate) in serum or plasma. Measurements of lithium are used to...

  20. 21 CFR 862.3560 - Lithium test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Lithium test system. 862.3560 Section 862.3560....3560 Lithium test system. (a) Identification. A lithium test system is a device intended to measure lithium (from the drug lithium carbonate) in serum or plasma. Measurements of lithium are used to...

  1. Silica Precipitation and Lithium Sorption

    SciTech Connect

    Jay Renew

    2015-09-20

    This file contains silica precipitation and lithium sorption data from the project. The silica removal data is corrected from the previous submission. The previous submission did not take into account the limit of detection of the ICP-MS procedure.

  2. Galileo lithium/SO2

    NASA Technical Reports Server (NTRS)

    Blagdon, L. J.

    1980-01-01

    The current status of the Galileo lithium SO2 battery is described. The following general requirements of the battery are discussed: (1) electrical characteristics, (2) storage, (3) reliability, and (4) performance.

  3. Dendrite preventing separator for secondary lithium batteries

    NASA Technical Reports Server (NTRS)

    Shen, David H. (Inventor); Surampudi, Subbarao (Inventor); Huang, Chen-Kuo (Inventor); Halpert, Gerald (Inventor)

    1993-01-01

    Dendrites are prevented from shorting a secondary lithium battery by use of a first porous separator, such as porous polypropylene, adjacent to the lithium anode that is unreactive with lithium and a second porous fluoropolymer separator between the cathode and the first separator, such as polytetrafluoroethylene, that is reactive with lithium. As the tip of a lithium dendrite contacts the second separator, an exothermic reaction occurs locally between the lithium dendrite and the fluoropolymer separator. This results in the prevention of the dendrite propagation to the cathode.

  4. Dendrite preventing separator for secondary lithium batteries

    NASA Technical Reports Server (NTRS)

    Shen, David H. (Inventor); Surampudi, Subbarao (Inventor); Huang, Chen-Kuo (Inventor); Halpert, Gerald (Inventor)

    1995-01-01

    Dendrites are prevented from shorting a secondary lithium battery by use of a first porous separator such as porous polypropylene adjacent the lithium anode that is unreactive with lithium and a second porous fluoropolymer separator between the cathode and the first separator such as polytetrafluoroethylene that is reactive with lithium. As the tip of a lithium dendrite contacts the second separator, an exothermic reaction occurs locally between the lithium dendrite and the fluoropolymer separator. This results in the prevention of the dendrite propagation to the cathode.

  5. Lithium compensation for full cell operation

    DOEpatents

    Xiao, Jie; Zheng, Jianming; Chen, Xilin; Lu, Dongping; Liu, Jun; Jiguang, Jiguang

    2016-05-17

    Disclosed herein are embodiments of a lithium-ion battery system comprising an anode, an anode current collector, and a layer of lithium metal in contact with the current collector, but not in contact with the anode. The lithium compensation layer dissolves into the electrolyte to compensate for the loss of lithium ions during usage of the full cell. The specific placement of the lithium compensation layer, such that there is no direct physical contact between the lithium compensation layer and the anode, provides certain advantages.

  6. Secondary lithium batteries for space applications

    NASA Technical Reports Server (NTRS)

    Carter, B.; Khanna, S. K.; Yen, S. P. S.; Shen, D.; Somoano, R. B.

    1981-01-01

    Secondary lithium cells which use a LiAsF6-2-Me-THF electrolyte and a TiS2 intercalatable cathode exhibit encouraging cycle life at ambient temperature. Electrochemical and surface analytical studies indicate that the electrolyte is unstable in the presence of metallic lithium, leading to the formation of a lithium passivating film composed of lithium arsenic oxyfluorides and lithium fluorsilicates. The lithium cyclability remains as the most important problem to solve. Different electrolyte solvents, such as sulfolane, exhibit promising characteristics but lead to new compatibility problems with the other cell component materials.

  7. Modeling the Lithium Ion Battery

    ERIC Educational Resources Information Center

    Summerfield, John

    2013-01-01

    The lithium ion battery will be a reliable electrical resource for many years to come. A simple model of the lithium ions motion due to changes in concentration and voltage is presented. The battery chosen has LiCoO[subscript 2] as the cathode, LiPF[subscript 6] as the electrolyte, and LiC[subscript 6] as the anode. The concentration gradient and…

  8. Lithium-iodine pacemaker cell

    SciTech Connect

    Schneider, A.A.; Snyder, S.E.; DeVan, T.; Harney, M.J.; Harney, D.E.

    1980-01-01

    The lithium-iodine pacemaker cell is described as supplied by several manufacturers. The features of each design are discussed along with their effect on energy density, self-discharge and shape of the discharge curve. Differences in performance characteristics are related to morphology of the lithium iodine electrolyte and to the form of the cathode. A new, high-drain cell is mentioned which can supply 60 /mu/a/cm/sup 2/. 10 refs.

  9. Air breathing lithium power cells

    SciTech Connect

    Farmer, Joseph C.

    2014-07-15

    A cell suitable for use in a battery according to one embodiment includes a catalytic oxygen cathode; a stabilized zirconia electrolyte for selective oxygen anion transport; a molten salt electrolyte; and a lithium-based anode. A cell suitable for use in a battery according to another embodiment includes a catalytic oxygen cathode; an electrolyte; a membrane selective to molecular oxygen; and a lithium-based anode.

  10. Efficiently photo-charging lithium-ion battery by perovskite solar cell.

    PubMed

    Xu, Jiantie; Chen, Yonghua; Dai, Liming

    2015-08-27

    Electric vehicles using lithium-ion battery pack(s) for propulsion have recently attracted a great deal of interest. The large-scale practical application of battery electric vehicles may not be realized unless lithium-ion batteries with self-charging suppliers will be developed. Solar cells offer an attractive option for directly photo-charging lithium-ion batteries. Here we demonstrate the use of perovskite solar cell packs with four single CH3NH3PbI3 based solar cells connected in series for directly photo-charging lithium-ion batteries assembled with a LiFePO4 cathode and a Li4Ti5O12 anode. Our device shows a high overall photo-electric conversion and storage efficiency of 7.80% and excellent cycling stability, which outperforms other reported lithium-ion batteries, lithium-air batteries, flow batteries and super-capacitors integrated with a photo-charging component. The newly developed self-chargeable units based on integrated perovskite solar cells and lithium-ion batteries hold promise for various potential applications.

  11. Efficiently photo-charging lithium-ion battery by perovskite solar cell.

    PubMed

    Xu, Jiantie; Chen, Yonghua; Dai, Liming

    2015-01-01

    Electric vehicles using lithium-ion battery pack(s) for propulsion have recently attracted a great deal of interest. The large-scale practical application of battery electric vehicles may not be realized unless lithium-ion batteries with self-charging suppliers will be developed. Solar cells offer an attractive option for directly photo-charging lithium-ion batteries. Here we demonstrate the use of perovskite solar cell packs with four single CH3NH3PbI3 based solar cells connected in series for directly photo-charging lithium-ion batteries assembled with a LiFePO4 cathode and a Li4Ti5O12 anode. Our device shows a high overall photo-electric conversion and storage efficiency of 7.80% and excellent cycling stability, which outperforms other reported lithium-ion batteries, lithium-air batteries, flow batteries and super-capacitors integrated with a photo-charging component. The newly developed self-chargeable units based on integrated perovskite solar cells and lithium-ion batteries hold promise for various potential applications. PMID:26311589

  12. Efficiently photo-charging lithium-ion battery by perovskite solar cell

    NASA Astrophysics Data System (ADS)

    Xu, Jiantie; Chen, Yonghua; Dai, Liming

    2015-08-01

    Electric vehicles using lithium-ion battery pack(s) for propulsion have recently attracted a great deal of interest. The large-scale practical application of battery electric vehicles may not be realized unless lithium-ion batteries with self-charging suppliers will be developed. Solar cells offer an attractive option for directly photo-charging lithium-ion batteries. Here we demonstrate the use of perovskite solar cell packs with four single CH3NH3PbI3 based solar cells connected in series for directly photo-charging lithium-ion batteries assembled with a LiFePO4 cathode and a Li4Ti5O12 anode. Our device shows a high overall photo-electric conversion and storage efficiency of 7.80% and excellent cycling stability, which outperforms other reported lithium-ion batteries, lithium-air batteries, flow batteries and super-capacitors integrated with a photo-charging component. The newly developed self-chargeable units based on integrated perovskite solar cells and lithium-ion batteries hold promise for various potential applications.

  13. Overview of Final CDX-U Experiments with Lithium Plasma-Facing Components

    NASA Astrophysics Data System (ADS)

    Kaita, R.; Majeski, R.; Gray, T.; Kugel, H.; Mansfield, D.; Spaleta, J.; Timberlake, J.; Zakharov, L.; Doerner, R.; Lynch, T.; Maingi, R.; Soukhanovskii, V.

    2006-10-01

    The final phase of Current Drive eXperiment Upgrade (CDX-U) research involved plasma-facing surfaces nearly completely coated with lithium. The CDX-U device is a spherical tokamak with the following typical parameters: R=34 cm, a=22 cm, Bt=2 kG, Ip=100 kA, Te(0)=100 eV, and ne(0)=5x10^19 m-3. Electron beam-induced evaporation from a lithium target and vapor deposition from a lithium-filled oven created lithium coatings. Convective flows for highly-efficient power dissipation were observed in the lithium with electron beam heating. Lithium layers up to 100 nm thick between were deposited between discharges. These coatings reduced global recycling coefficients to as low as 0.3, a record for magnetically-confined hydrogen plasmas. New magnetic diagnostics constrained equilibrium reconstructions that were used to determine energy confinement times. With lithium coatings, plasmas had the largest global confinement enhancement ever achieved in an Ohmically-heated tokamak, exceeding ITER98P(y,1) scaling by up to a factor of three.

  14. Lithium recovery from brine using a λ-MnO2/activated carbon hybrid supercapacitor system.

    PubMed

    Kim, Seoni; Lee, Jaehan; Kang, Jin Soo; Jo, Kyusik; Kim, Seonghwan; Sung, Yung-Eun; Yoon, Jeyong

    2015-04-01

    Lithium is one of the most important elements in various fields including energy storage, medicine manufacturing and the glass industry, and demands for lithium are constantly increasing these days. The lime soda evaporation process using brine lake water is the major extraction method for lithium, but this process is not only inefficient and time-consuming but also causes a few environmental problems. Electrochemical recovery processes of lithium ions have been proposed recently, but the better idea for the silver negative electrodes used in these systems is required to reduce its cost or increase long term stability. Here, we report an electrochemical lithium recovery method based on a λ-MnO2/activated carbon hybrid supercapacitor system. In this system, lithium ions and counter anions are effectively captured at each electrode with low energy consumption in a salt solution containing various cationic species or simulated Salar de Atacama brine lake water in Chile. Furthermore, we designed this system as a flow process for practical applications. By experimental analyses, we confirmed that this system has high selectivity and long-term stability, with its performance being retained even after repetitive captures and releases of lithium ions. PMID:25681679

  15. Lithium recovery from brine using a λ-MnO2/activated carbon hybrid supercapacitor system.

    PubMed

    Kim, Seoni; Lee, Jaehan; Kang, Jin Soo; Jo, Kyusik; Kim, Seonghwan; Sung, Yung-Eun; Yoon, Jeyong

    2015-04-01

    Lithium is one of the most important elements in various fields including energy storage, medicine manufacturing and the glass industry, and demands for lithium are constantly increasing these days. The lime soda evaporation process using brine lake water is the major extraction method for lithium, but this process is not only inefficient and time-consuming but also causes a few environmental problems. Electrochemical recovery processes of lithium ions have been proposed recently, but the better idea for the silver negative electrodes used in these systems is required to reduce its cost or increase long term stability. Here, we report an electrochemical lithium recovery method based on a λ-MnO2/activated carbon hybrid supercapacitor system. In this system, lithium ions and counter anions are effectively captured at each electrode with low energy consumption in a salt solution containing various cationic species or simulated Salar de Atacama brine lake water in Chile. Furthermore, we designed this system as a flow process for practical applications. By experimental analyses, we confirmed that this system has high selectivity and long-term stability, with its performance being retained even after repetitive captures and releases of lithium ions.

  16. Lithium peroxide primary element

    SciTech Connect

    Winsel, A.

    1985-03-12

    In a galvanic primary element of the system Li/H/sub 2/O/sub 2/, the aqueous cathode depolarizer H/sub 2/O/sub 2/ is fixated as a polyurethane gel. It can thereby be controlled and caused to react with anode metal in accordance with the current drain requirements. This is accomplished using a ram to press the gel toward a conductor which covers the lithium anode, which may take the form of a metal grid and/or a gas diffusion electrode. The oxygen which forms in the working layer through catalytic decomposition of hydrogen peroxide creates a gas bubble when the current is interrupted or the ram is stopped, thereby interrupting the further supply of hydrogen peroxide to the catalyst.

  17. Lithium peroxide primary element

    SciTech Connect

    Winsel, A.

    1982-05-04

    In a galvanic primary element of the system Li/H/sub 2/O/sub 2/, the aqueous cathode depolarizer H/sub 2/O/sub 2/ is fixated as a polyurethane gel. It can thereby be controlled and caused to react with the anode metal in accordance with the current drain requirements. This is accomplished using a ram to press the gel toward a conductor which covers the lithium anode, which may take the form of a metal grid and/or a gas diffusion electrode. The oxygen which forms in the working layer through catalytic decomposition of hydrogen peroxide creates a gas bubble when the current is interrupted or the ram is stopped, thereby interrupting the further supply of hydrogen peroxide to the catalyst.

  18. STREMR: Numerical model for depth-averaged incompressible flow

    NASA Astrophysics Data System (ADS)

    Roberts, Bernard

    1993-09-01

    The STREMR computer code is a two-dimensional model for depth-averaged incompressible flow. It accommodates irregular boundaries and nonuniform bathymetry, and it includes empirical corrections for turbulence and secondary flow. Although STREMR uses a rigid-lid surface approximation, the resulting pressure is equivalent to the displacement of a free surface. Thus, the code can be used to model free-surface flow wherever the local Froude number is 0.5 or less. STREMR uses a finite-volume scheme to discretize and solve the governing equations for primary flow, secondary flow, and turbulence energy and dissipation rate. The turbulence equations are taken from the standard k-Epsilon turbulence model, and the equation for secondary flow is developed herein. Appendices to this report summarize the principal equations, as well as the procedures used for their discrete solution.

  19. High power density self-cooled lithium-vanadium blanket.

    SciTech Connect

    Gohar, Y.; Majumdar, S.; Smith, D.

    1999-07-01

    A self-cooled lithium-vanadium blanket concept capable of operating with 2 MW/m{sup 2} surface heat flux and 10 MW/m{sup 2} neutron wall loading has been developed. The blanket has liquid lithium as the tritium breeder and the coolant to alleviate issues of coolant breeder compatibility and reactivity. Vanadium alloy (V-4Cr-4Ti) is used as the structural material because it can accommodate high heat loads. Also, it has good mechanical properties at high temperatures, high neutron fluence capability, low degradation under neutron irradiation, good compatibility with the blanket materials, low decay heat, low waste disposal rating, and adequate strength to accommodate the electromagnetic loads during plasma disruption events. Self-healing electrical insulator (CaO) is utilized to reduce the MHD pressure drop. A poloidal coolant flow with high velocity at the first wall is used to reduce the peak temperature of the vanadium structure and to accommodate high surface heat flux. The blanket has a simple blanket configuration and low coolant pressure to reduce the fabrication cost, to improve the blanket reliability, and to increase confidence in the blanket performance. Spectral shifter, moderator, and reflector are utilized to improve the blanket shielding capability and energy multiplication, and to reduce the radial blanket thickness. Natural lithium is used to avoid extra cost related to the lithium enrichment process.

  20. A new lithium salt with dihydroxybenzene and lithium tetrafluoroborate for lithium battery electrolytes

    NASA Astrophysics Data System (ADS)

    Xue, Zhao-Ming; Sun, Bin-Bin; Zhou, Wei; Chen, Chun-Hua

    2011-10-01

    A new unsymmetrical lithium salt containing F-, C6H4O22- [dianion of 1,2-benzenediol], lithium difluoro(1,2-benzene-diolato(2-)-o,o‧)borate (LDFBDB) is synthesized and characterized. Its thermal decomposition in nitrogen begins at 170 °C. The cyclic voltammetry study shows that the LDFBDB solution in propylene carbonate (PC) is stable up to 3.7 V versus Li+/Li. It is soluble in common organic solvents. The ionic dissociation properties of LDFBDB are examined by conductivity measurements in PC, PC+ ethyl methyl carbonate (EMC), PC + dimethyl ether (DME), PC + ethylene carbonate (EC) + EMC solutions. The conductivity values of the 0.564 mol dm-3 LDFBDB electrolyte in PC + DME solution is 3.90 mS cm-1. All these properties of the new lithium salt including the thermal characteristics, electrochemical stabilities, solubilities, ionic dissociation properties are studied and compared with those of its derivatives, lithium difluoro(3-fluoro-1,2-benzene-diolato(2-)-o,o‧)borate (FLDFBDB), lithium [3-fluoro-1,2-benzenediolato(2-)-o,o‧ oxalato]borate (FLBDOB), and lithium bis(oxalate)borate (LBOB).

  1. Phosphoryl-rich flame-retardant ions (FRIONs): towards safer lithium-ion batteries.

    PubMed

    Rectenwald, Michael F; Gaffen, Joshua R; Rheingold, Arnold L; Morgan, Alexander B; Protasiewicz, John D

    2014-04-14

    The functionalized catecholate, tetraethyl (2,3-dihydroxy-1,4-phenylene)bis(phosphonate) (H2 -DPC), has been used to prepare a series of lithium salts Li[B(DPC)(oxalato)], Li[B(DPC)2], Li[B(DPC)F2], and Li[P(DPC)3]. The phosphoryl-rich character of these anions was designed to impart flame-retardant properties for their use as potential flame-retardant ions (FRIONs), additives, or replacements for other lithium salts for safer lithium-ion batteries. The new materials were fully characterized, and the single-crystal structures of Li[B(DPC)(oxalato)] and Li[P(DPC)3] have been determined. Thermogravimetric analysis of the four lithium salts show that they are thermally stable up to around 200 °C. Pyrolysis combustion flow calorimetry reveals that these salts produce high char yields upon combustion.

  2. Phosphoryl-rich flame-retardant ions (FRIONs): towards safer lithium-ion batteries.

    PubMed

    Rectenwald, Michael F; Gaffen, Joshua R; Rheingold, Arnold L; Morgan, Alexander B; Protasiewicz, John D

    2014-04-14

    The functionalized catecholate, tetraethyl (2,3-dihydroxy-1,4-phenylene)bis(phosphonate) (H2 -DPC), has been used to prepare a series of lithium salts Li[B(DPC)(oxalato)], Li[B(DPC)2], Li[B(DPC)F2], and Li[P(DPC)3]. The phosphoryl-rich character of these anions was designed to impart flame-retardant properties for their use as potential flame-retardant ions (FRIONs), additives, or replacements for other lithium salts for safer lithium-ion batteries. The new materials were fully characterized, and the single-crystal structures of Li[B(DPC)(oxalato)] and Li[P(DPC)3] have been determined. Thermogravimetric analysis of the four lithium salts show that they are thermally stable up to around 200 °C. Pyrolysis combustion flow calorimetry reveals that these salts produce high char yields upon combustion. PMID:24615890

  3. Redox-assisted Li+-storage in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Qizhao, Huang; Qing, Wang

    2016-01-01

    Interfacial charge transfer is the key kinetic process dictating the operation of lithium-ion battery. Redox-mediated charge propagations of the electronic (e- and h+) and ionic species (Li+) at the electrode-electrolyte interface have recently gained increasing attention for better exploitation of battery materials. This article briefly summarises the energetic and kinetic aspects of lithium-ion batteries, and reviews the recent progress on various redox-assisted Li+ storage approaches. From molecular wiring to polymer wiring and from redox targeting to redox flow lithium battery, the role of redox mediators and the way of the redox species functioning in lithium-ion batteries are discussed. Project supported by the National Research Foundation, Prime Minister’s Office, Singapore under its Competitive Research Program (CRP Award No. NRF-CRP8-2011-04).

  4. A Simple Apparatus for the Injection of Lithium Aerosol into the Scrape-Off Layer of Fusion Research Devices

    SciTech Connect

    D. K. Mansfield, A.L Roquemore, H. Schneider, J. Timberlake, H. Kugel, M.G. Bell and the NSTX Research Team

    2010-10-11

    A simple device has been developed to deposit elemental lithium onto plasma facing components in the National Spherical Torus Experiment. Deposition is accomplished by dropping lithium powder into the plasma column. Once introduced, lithium particles quickly become entrained in scrape-off layer flow as an evaporating aerosol. Particles are delivered through a small central aperture in a computer-controlled resonating piezoelectric disk on which the powder is supported. The device has been used to deposit lithium both during discharges as well as prior to plasma breakdown. Clear improvements to plasma performance have been demonstrated. The use of this apparatus provides flexibility in the amount and timing of lithium deposition and, therefore, may benefit future fusion research devices.

  5. High performance discharges in the Lithium Tokamak eXperiment with liquid lithium wallsa)

    NASA Astrophysics Data System (ADS)

    Schmitt, J. C.; Bell, R. E.; Boyle, D. P.; Esposti, B.; Kaita, R.; Kozub, T.; LeBlanc, B. P.; Lucia, M.; Maingi, R.; Majeski, R.; Merino, E.; Punjabi-Vinoth, S.; Tchilingurian, G.; Capece, A.; Koel, B.; Roszell, J.; Biewer, T. M.; Gray, T. K.; Kubota, S.; Beiersdorfer, P.; Widmann, K.; Tritz, K.

    2015-05-01

    The first-ever successful operation of a tokamak with a large area (40% of the total plasma surface area) liquid lithium wall has been achieved in the Lithium Tokamak eXperiment (LTX). These results were obtained with a new, electron beam-based lithium evaporation system, which can deposit a lithium coating on the limiting wall of LTX in a five-minute period. Preliminary analyses of diamagnetic and other data for discharges operated with a liquid lithium wall indicate that confinement times increased by 10× compared to discharges with helium-dispersed solid lithium coatings. Ohmic energy confinement times with fresh lithium walls, solid and liquid, exceed several relevant empirical scaling expressions. Spectroscopic analysis of the discharges indicates that oxygen levels in the discharges limited on liquid lithium walls were significantly reduced compared to discharges limited on solid lithium walls. Tokamak operations with a full liquid lithium wall (85% of the total plasma surface area) have recently started.

  6. Protective lithium ion conducting ceramic coating for lithium metal anodes and associate method

    DOEpatents

    Bates, John B.

    1994-01-01

    A battery structure including a cathode, a lithium metal anode and an electrolyte disposed between the lithium anode and the cathode utilizes a thin-film layer of lithium phosphorus oxynitride overlying so as to coat the lithium anode and thereby separate the lithium anode from the electrolyte. If desired, a preliminary layer of lithium nitride may be coated upon the lithium anode before the lithium phosphorous oxynitride is, in turn, coated upon the lithium anode so that the separation of the anode and the electrolyte is further enhanced. By coating the lithium anode with this material lay-up, the life of the battery is lengthened and the performance of the battery is enhanced.

  7. High performance discharges in the Lithium Tokamak eXperiment with liquid lithium walls

    SciTech Connect

    Schmitt, J. C.; Bell, R. E.; Boyle, D. P.; Esposti, B.; Kaita, R.; Kozub, T.; LeBlanc, B. P.; Lucia, M.; Maingi, R.; Majeski, R.; Merino, E.; Punjabi-Vinoth, S.; Tchilingurian, G.; Capece, A.; Koel, B.; Roszell, J.; Biewer, T. M.; Gray, T. K.; Kubota, S.; Beiersdorfer, P.; and others

    2015-05-15

    The first-ever successful operation of a tokamak with a large area (40% of the total plasma surface area) liquid lithium wall has been achieved in the Lithium Tokamak eXperiment (LTX). These results were obtained with a new, electron beam-based lithium evaporation system, which can deposit a lithium coating on the limiting wall of LTX in a five-minute period. Preliminary analyses of diamagnetic and other data for discharges operated with a liquid lithium wall indicate that confinement times increased by 10× compared to discharges with helium-dispersed solid lithium coatings. Ohmic energy confinement times with fresh lithium walls, solid and liquid, exceed several relevant empirical scaling expressions. Spectroscopic analysis of the discharges indicates that oxygen levels in the discharges limited on liquid lithium walls were significantly reduced compared to discharges limited on solid lithium walls. Tokamak operations with a full liquid lithium wall (85% of the total plasma surface area) have recently started.

  8. Khalil Amine on Lithium-air Batteries

    SciTech Connect

    Khalil Amine

    2009-09-14

    Khalil Amine, materials scientist at Argonne National Laboratory, speaks on the new technology Lithium-air batteries, which could potentially increase energy density by 5-10 times over lithium-ion batteries.

  9. Khalil Amine on Lithium-air Batteries

    ScienceCinema

    Khalil Amine

    2016-07-12

    Khalil Amine, materials scientist at Argonne National Laboratory, speaks on the new technology Lithium-air batteries, which could potentially increase energy density by 5-10 times over lithium-ion batteries.

  10. Michael Thackeray on Lithium-air Batteries

    ScienceCinema

    Thackeray, Michael

    2016-07-12

    Michael Thackeray, Distinguished Fellow at Argonne National Laboratory, speaks on the new technology Lithium-air batteries, which could potentially increase energy density by 5-10 times over lithium-ion batteries.

  11. Fueling studies on the lithium tokamak experiment

    NASA Astrophysics Data System (ADS)

    Lundberg, Daniel Patrick

    Lithium plasma facing components reduce the flux of "recycled" particles entering the plasma edge from the plasma facing components. This results in increased external fueling requirements and provides the opportunity to control the magnitude and distribution of the incoming particle flux. It has been predicted that the plasma density profile will then be determined by the deposition profile of the external fueling, rather than dominated by the recycled particle flux. A series of experiments on the Lithium Tokamak Experiment demonstrate that lithium wall coatings facilitate control of the neutral and plasma particle inventories. With fresh lithium coatings and careful gas injection programming, over 90% of the injected particle inventory can be absorbed in the lithium wall during a discharge. Furthermore, dramatic changes in the fueling requirements and plasma parameters were observed when lithium coatings were applied. This is largely due to the elimination of water as an impurity on the plasma facing components. A Molecular Cluster Injector (MCI) was developed for the fueling of LTX plasmas. The MCI uses a supersonic nozzle, cooled to liquid nitrogen temperatures, to create the conditions necessary for molecular cluster formation. It has been predicted that molecular clusters will penetrate deeper into plasmas than gas-phase molecules via a reduced ionization cross-section and by improving the collimation of the neutral jet. Using an electron beam diagnostic, the densities of the cryogenic MCI are measured to be an order of magnitude higher than in the room-temperature jets formed with the same valve pressure. This indicates increased collimation relative to what would be expected from ideal gas dynamics alone. A systematic study of the fueling efficiencies achieved with the LTX fueling systems is presented. The fueling efficiency of the Supersonic Gas Injector (SGI) is demonstrated to be strongly dependent on the distance between the nozzle and plasma edge. The

  12. Plasma Performance Improvements with Liquid Lithium Limiters in CDX-U

    SciTech Connect

    R. Majeski; M. Boaz; D. Hoffman; B. Jones; R. Kaita; H. Kugel; T. Munsat; J. Spaleta; V. Soukhanovskii; J. Timberlake; L. Zakharov; G. Antar; R. Doerner; S. Luckhardt; R.W. Conn; M. Finkenthal; D. Stutman; R. Maingi; and M. Ulrickson

    2002-07-12

    The use of flowing liquid lithium as a first wall for a reactor has potentially attractive physics and engineering features. The Current Drive experiment-Upgrade (CDX-U) at the Princeton Plasma Physics Laboratory has begun experiments with a fully toroidal liquid lithium limiter. CDX-U is a compact [R = 34 cm, a = 22 cm, Btoroidal = 2 kG, IP =100 kA, T(subscript)e(0) {approx} 100 eV, n(subscript)e(0) {approx} 5 x 10{sup 19} m-3] short-pulse (<25 msec) spherical tokamak with extensive diagnostics. The limiter, which consists of a shallow circular stainless steel tray of radius 34 cm and width 10 cm, can be filled with lithium to a depth of a few millimeters, and forms the lower limiting surface for the discharge. Heating elements beneath the tray are used to liquefy the lithium prior to the experiment. The total area of the tray is approximately 2000 cm{sup 2}. The tokamak edge plasma, when operated in contact with the lithium-filled tray, shows evidence of reduced impurities and recycling. The reduction in re cycling and impurities is largest when the lithium is liquefied by heating to 250 degrees Celsius. Discharges which are limited by the liquid lithium tray show evidence of performance enhancement. Radiated power is reduced and there is spectroscopic evidence for increases in the core electron temperature. Furthermore, the use of a liquid lithium limiter reduces the need for conditioning discharges prior to high current operation. The future development path for liquid lithium limiter systems in CDX-U is also discussed.

  13. Sixty years of lithium responders.

    PubMed

    Grof, Paul

    2010-01-01

    It has been 60 years since Cade first described patients who responded to antimanic lithium treatment. Two decades later, responders to lithium stabilization emerged in larger numbers. The responses of many severely ill bipolar patients to lithium were striking and called for an explanation. Remarkable reactions to a simple ion generated hope for an uncomplicated laboratory test of response and an extensive search for suitable biological markers ensued. But despite promising reports, particularly from molecular genetics, we are still waiting for a biological elucidation of the stabilizing effects of lithium. The most useful predictor of lithium stabilization has to date been the patient's clinical profile, based on a comprehensive clinical assessment: complete remissions and other characteristics of episodic clinical course, bipolar family history, low psychiatric comorbidity and a characteristic presenting psychopathology. In brief, the responders approximate the classical Kraepelinian description of a manic-depressive patient. But the most intriguing findings have recently emerged from prospective observations of the next generation: the children of lithium responders, their counterparts coming from parents who did not respond to lithium and controls. Overall, they indicate that parents and offspring suffer from a comparable brain dysfunction that manifests clinically in distinct stages. If the child's predicament starts early in childhood, it presents with varied, nonaffective or subclinical manifestations that are usually nonresponsive to standard treatments prescribed according to the symptoms. The next stage then unfolds in adolescence, first with depressive and later with activated episodes. The observations have a potential to markedly enrich the prevailing understanding and management of mood disorders. PMID:20453530

  14. Multi-layered, chemically bonded lithium-ion and lithium/air batteries

    DOEpatents

    Narula, Chaitanya Kumar; Nanda, Jagjit; Bischoff, Brian L; Bhave, Ramesh R

    2014-05-13

    Disclosed are multilayer, porous, thin-layered lithium-ion batteries that include an inorganic separator as a thin layer that is chemically bonded to surfaces of positive and negative electrode layers. Thus, in such disclosed lithium-ion batteries, the electrodes and separator are made to form non-discrete (i.e., integral) thin layers. Also disclosed are methods of fabricating integrally connected, thin, multilayer lithium batteries including lithium-ion and lithium/air batteries.

  15. Novel Electrolytes for Lithium Ion Batteries

    SciTech Connect

    Lucht, Brett L.

    2014-12-12

    We have been investigating three primary areas related to lithium ion battery electrolytes. First, we have been investigating the thermal stability of novel electrolytes for lithium ion batteries, in particular borate based salts. Second, we have been investigating novel additives to improve the calendar life of lithium ion batteries. Third, we have been investigating the thermal decomposition reactions of electrolytes for lithium-oxygen batteries.

  16. Rechargeable lithium battery technology - A survey

    NASA Technical Reports Server (NTRS)

    Halpert, Gerald; Surampudi, Subbarao

    1990-01-01

    The technology of the rechargeable lithium battery is discussed with special attention given to the types of rechargeable lithium cells and to their expected performance and advantages. Consideration is also given to the organic-electrolyte and polymeric-electrolyte cells and to molten salt lithium cells, as well as to technical issues, such as the cycle life, charge control, rate capability, cell size, and safety. The role of the rechargeable lithium cell in future NASA applications is discussed.

  17. Primary lithium batteries, some consumer considerations

    NASA Technical Reports Server (NTRS)

    Bro, P.

    1983-01-01

    In order to determine whether larger size lithium batteries would be commercially marketable, the performance of several D size lithium batteries was compared with that of an equivalent alkaline manganese battery, and the relative costs of the different systems were compared. It is concluded that opportunities exist in the consumer market for the larger sizes of the low rate and moderate rate lithium batteries, and that the high rate lithium batteries need further improvements before they can be recommended for consumer applications.

  18. Lithium in Medicine: Mechanisms of Action.

    PubMed

    Mota de Freitas, Duarte; Leverson, Brian D; Goossens, Jesse L

    2016-01-01

    In this chapter, we review the mechanism of action of lithium salts from a chemical perspective. A description on how lithium salts are used to treat mental illnesses, in particular bipolar disorder, and other disease states is provided. Emphasis is not placed on the genetics and the psychopharmacology of the ailments for which lithium salts have proven to be beneficial. Rather we highlight the application of chemical methodologies for the characterization of the cellular targets of lithium salts and their distribution in tissues.

  19. Instability suppression in viscoelastic film flows down an inclined plane lined with a deformable solid layer.

    PubMed

    Jain, Aashish; Shankar, V

    2007-10-01

    The linear stability of viscoelastic (Oldroyd-B) film flow down an inclined plane lined with a deformable (neo-Hookean) solid layer is analyzed using low-wave-number asymptotic analysis and the Chebyshev-Tau spectral numerical method. The free surface of film flows of viscoelastic liquids, unlike that of their Newtonian counterparts, becomes unstable in flow down a rigid inclined surface even in the absence of fluid inertia, due to the elastic nature of the liquids. For film flow past a deformable solid, our low-wave-number asymptotic analysis reveals that the solid deformability has a stabilizing effect on the free-surface instability, and, remarkably, this prediction is insensitive to rheology of the liquid film, be it viscoelastic or Newtonian. Using the spectral numerical method, we demonstrate that the free-surface instability can be completely suppressed at all wave numbers when the solid becomes sufficiently deformable. For the case of pure polymeric liquids without any solvent, when the solid layer is made further deformable, both the free surface and the liquid-solid interface are destabilized at finite wave numbers. We also demonstrate a type of mode exchange phenomenon between the modes corresponding to the two interfaces. Importantly, our numerical results show that there is a sufficient range of shear modulus of the solid where both the modes are stable at all wave numbers. For polymer solutions described by the Oldroyd-B model, while the free-surface instability is suppressed by the deformable solid, a host of new unstable modes appear at finite Reynolds number and wave number because of the coupling between liquid flow and free shear waves in the solid. Our study thus demonstrates that the elastohydrodynamic coupling between liquid flow and solid deformation can be exploited either to suppress the free-surface instability (present otherwise in rigid inclines) in viscoelastic film flows, or to induce new instabilities that are absent in flow adjacent

  20. Hydrodynamic simulation of a lithium chloride salt system.

    SciTech Connect

    Eberle, C. S.; Herrmann, S. D.; Knighton, G. C.

    1999-02-12

    A fused lithium chloride salt system's constitutive properties were evaluated and compared to a number of fluid properties, and water was shown to be an excellent simulant of lithium chloride salt. With a simple flow model, the principal scaling term was shown to be a function of the kinematic viscosity. A water mock-up of the molten salt was also shown to be within a {+-}3% error in the scaling analysis. This made it possible to consider developing water scaled tests of the molten salt system. Accurate flow velocity and pressure measurements were acquired by developing a directional velocity probe. The device was constructed and calibrated with a repeatable accuracy of {+-}15%. This was verified by a detailed evaluation of the probe. Extensive flow measurements of the engineering scale mockup were conducted, and the results were carefully compared to radial flow patterns of a straight blade stirrer. The flow measurements demonstrated an anti-symmetric nature of the stirring, and many additional effects were also identified. The basket design was shown to prevent fluid penetration into the fuel baskets when external stirring was the flow mechanism.

  1. NASA/Marshall's lithium battery applications

    NASA Technical Reports Server (NTRS)

    Paschal, L. E.

    1980-01-01

    A general lithium battery is described and a summary of lithium battery applications is presented. Four aspects of a particular lithium battery, the inducement environmental contamination monitoring battery, are discussed-design and construction details, thermal vacuum tests, projection tests, and acceptance tests.

  2. Army position on lithium battery safety

    NASA Technical Reports Server (NTRS)

    Reiss, E.

    1982-01-01

    User requirements for lithium sulfur batteries are presented. They include careful analysis of design and quality control, along with certain equipment specifications. Some of the specifications include: hermetically sealed cells; lithium limited cells with stoichiometry of lithium to sulfur dioxide as a ratio of one; low moisture content in the cells; and battery capacity.

  3. Aplastic anemia associated with lithium therapy

    PubMed Central

    Hussain, M. Z.; Khan, A. G.; Chaudhry, Z. A.

    1973-01-01

    A case is reported of fatal aplastic anemia developing in a 50-year-old woman who received lithium carbonate in the generally accepted dosage for a manic-depressive disorder. The serum lithium had been determined at regular intervals and never exceeded what is considered a safe level. Patients for whom lithium is prescribed should have periodic hematologic examinations. PMID:4691107

  4. Magnetism in lithium-oxygen discharge product.

    PubMed

    Lu, Jun; Jung, Hun-Ji; Lau, Kah Chun; Zhang, Zhengcheng; Schlueter, John A; Du, Peng; Assary, Rajeev S; Greeley, Jeffrey; Ferguson, Glen A; Wang, Hsien-Hau; Hassoun, Jusef; Iddir, Hakim; Zhou, Jigang; Zuin, Lucia; Hu, Yongfeng; Sun, Yang-Kook; Scrosati, Bruno; Curtiss, Larry A; Amine, Kahlil

    2013-07-01

    Nonaqueous lithium-oxygen batteries have a much superior theoretical gravimetric energy density compared to conventional lithium-ion batteries, and thus could render long-range electric vehicles a reality. A molecular-level understanding of the reversible formation of lithium peroxide in these batteries, the properties of major/minor discharge products, and the stability of the nonaqueous electrolytes is required to achieve successful lithium-oxygen batteries. We demonstrate that the major discharge product formed in the lithium-oxygen cell, lithium peroxide, exhibits a magnetic moment. These results are based on dc-magnetization measurements and a lithium-oxygen cell containing an ether-based electrolyte. The results are unexpected because bulk lithium peroxide has a significant band gap. Density functional calculations predict that superoxide-type surface oxygen groups with unpaired electrons exist on stoichiometric lithium peroxide crystalline surfaces and on nanoparticle surfaces; these computational results are consistent with the magnetic measurement of the discharged lithium peroxide product as well as EPR measurements on commercial lithium peroxide. The presence of superoxide-type surface oxygen groups with spin can play a role in the reversible formation and decomposition of lithium peroxide as well as the reversible formation and decomposition of electrolyte molecules. PMID:23670967

  5. Electrochemical isotope effect and lithium isotope separation.

    PubMed

    Black, Jay R; Umeda, Grant; Dunn, Bruce; McDonough, William F; Kavner, Abby

    2009-07-29

    A large electrochemical isotopic effect is observed upon the electrodeposition of lithium from solutions of propylene carbonate producing isotopically light metal deposits. The magnitude of fractionation is controlled by the applied overpotential and is largest close to equilibrium. Calculated partition function ratios for tetrahedrally coordinated lithium complexes and metallic lithium predict an equilibrium fractionation close to that measured experimentally.

  6. [Lithium induced dysfunction of the parathyroid hormone].

    PubMed

    Valeur, Nana; Andersen, Rikke Steen

    2002-01-28

    The prevalence of hyperparathyroidism (HPT) in patients treated with lithium is higher than that in controls. Lithium seems to affect calcium metabolism, by acting directly parathyroid hormone cells, and distal tubuli in the kidneys. Because hypercalcaemic HPT can cause psychiatric symptoms mistakenly attributed to the lithium treatment, ionised calcium should be a standard control.

  7. Anode materials for lithium-ion batteries

    DOEpatents

    Sunkara, Mahendra Kumar; Meduri, Praveen; Sumanasekera, Gamini

    2014-12-30

    An anode material for lithium-ion batteries is provided that comprises an elongated core structure capable of forming an alloy with lithium; and a plurality of nanostructures placed on a surface of the core structure, with each nanostructure being capable of forming an alloy with lithium and spaced at a predetermined distance from adjacent nanostructures.

  8. Solid composite electrolytes for lithium batteries

    DOEpatents

    Kumar, Binod; Scanlon, Jr., Lawrence G.

    2000-01-01

    Solid composite electrolytes are provided for use in lithium batteries which exhibit moderate to high ionic conductivity at ambient temperatures and low activation energies. In one embodiment, a ceramic-ceramic composite electrolyte is provided containing lithium nitride and lithium phosphate. The ceramic-ceramic composite is also preferably annealed and exhibits an activation energy of about 0.1 eV.

  9. Magnetism in lithium-oxygen discharge product.

    PubMed

    Lu, Jun; Jung, Hun-Ji; Lau, Kah Chun; Zhang, Zhengcheng; Schlueter, John A; Du, Peng; Assary, Rajeev S; Greeley, Jeffrey; Ferguson, Glen A; Wang, Hsien-Hau; Hassoun, Jusef; Iddir, Hakim; Zhou, Jigang; Zuin, Lucia; Hu, Yongfeng; Sun, Yang-Kook; Scrosati, Bruno; Curtiss, Larry A; Amine, Kahlil

    2013-07-01

    Nonaqueous lithium-oxygen batteries have a much superior theoretical gravimetric energy density compared to conventional lithium-ion batteries, and thus could render long-range electric vehicles a reality. A molecular-level understanding of the reversible formation of lithium peroxide in these batteries, the properties of major/minor discharge products, and the stability of the nonaqueous electrolytes is required to achieve successful lithium-oxygen batteries. We demonstrate that the major discharge product formed in the lithium-oxygen cell, lithium peroxide, exhibits a magnetic moment. These results are based on dc-magnetization measurements and a lithium-oxygen cell containing an ether-based electrolyte. The results are unexpected because bulk lithium peroxide has a significant band gap. Density functional calculations predict that superoxide-type surface oxygen groups with unpaired electrons exist on stoichiometric lithium peroxide crystalline surfaces and on nanoparticle surfaces; these computational results are consistent with the magnetic measurement of the discharged lithium peroxide product as well as EPR measurements on commercial lithium peroxide. The presence of superoxide-type surface oxygen groups with spin can play a role in the reversible formation and decomposition of lithium peroxide as well as the reversible formation and decomposition of electrolyte molecules.

  10. Conductive lithium storage electrode

    DOEpatents

    Chiang, Yet-Ming; Chung, Sung-Yoon; Bloking, Jason T.; Andersson, Anna M.

    2012-04-03

    A compound comprising a composition A.sub.x(M'.sub.1-aM''.sub.a).sub.y(XD.sub.4).sub.z, A.sub.x(M'.sub.1-aM''.sub.a).sub.y(DXD.sub.4).sub.z, or A.sub.x(M'.sub.1-aM''.sub.a).sub.y(X.sub.2D.sub.7).sub.z, and have values such that x, plus y(1-a) times a formal valence or valences of M', plus ya times a formal valence or valence of M'', is equal to z times a formal valence of the XD.sub.4, X.sub.2D.sub.7, or DXD.sub.4 group; or a compound comprising a composition (A.sub.1-aM''.sub.a).sub.xM'.sub.y(XD.sub.4).sub.z, (A.sub.1-aM''.sub.a).sub.xM'.sub.y(DXD.sub.4).sub.z (A.sub.1-aM''.sub.a).sub.xM'.sub.y(X.sub.2D.sub.7).sub.z and have values such that (1-a).sub.x plus the quantity ax times the formal valence or valences of M'' plus y times the formal valence or valences of M' is equal to z times the formal valence of the XD.sub.4, X.sub.2D.sub.7 or DXD.sub.4 group. In the compound, A is at least one of an alkali metal and hydrogen, M' is a first-row transition metal, X is at least one of phosphorus, sulfur, arsenic, molybdenum, and tungsten, M'' any of a Group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, D is at least one of oxygen, nitrogen, carbon, or a halogen, 0.0001lithium phosphate that can intercalate lithium or hydrogen. The compound can be used in an electrochemical device including electrodes and storage batteries and can have a gravimetric capacity of at least about 80 mAh/g while being charged/discharged at greater than about C rate of the compound.

  11. Conductive lithium storage electrode

    DOEpatents

    Chiang, Yet-Ming; Chung, Sung-Yoon; Bloking, Jason T.; Andersson, Anna M.

    2008-03-18

    A compound comprising a composition A.sub.x(M'.sub.1-aM''.sub.a).sub.y(XD.sub.4).sub.z, A.sub.x(M'.sub.1-aM''.sub.a).sub.y(DXD.sub.4).sub.z, or A.sub.x(M'.sub.1-aM''.sub.a).sub.y(X.sub.2D.sub.7).sub.z, and have values such that x, plus y(1-a) times a formal valence or valences of M', plus ya times a formal valence or valence of M'', is equal to z times a formal valence of the XD.sub.4, X.sub.2D.sub.7, or DXD.sub.4 group; or a compound comprising a composition (A.sub.1-aM''.sub.a).sub.xM'.sub.y(XD.sub.4).sub.z, (A.sub.1-aM''.sub.a).sub.xM'.sub.y(DXD.sub.4).sub.z(A.sub.1-aM''.sub.a).s- ub.xM'.sub.y(X.sub.2D.sub.7).sub.z and have values such that (1-a).sub.x plus the quantity ax times the formal valence or valences of M'' plus y times the formal valence or valences of M' is equal to z times the formal valence of the XD.sub.4, X.sub.2D.sub.7 or DXD.sub.4 group. In the compound, A is at least one of an alkali metal and hydrogen, M' is a first-row transition metal, X is at least one of phosphorus, sulfur, arsenic, molybdenum, and tungsten, M'' any of a Group IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IIIB, IVB, VB, and VIB metal, D is at least one of oxygen, nitrogen, carbon, or a halogen, 0.0001lithium phosphate that can intercalate lithium or hydrogen. The compound can be used in an electrochemical device including electrodes and storage batteries and can have a gravimetric capacity of at least about 80 mAh/g while being charged/discharged at greater than about C rate of the compound.

  12. Numerical simulation of fluid flow and heat transfer in a thin liquid film over a rotating disk

    NASA Technical Reports Server (NTRS)

    Rahman, M. M.; Faghri, A.

    1992-01-01

    The results of a numerical simulation of the flow field and associated heat transfer coefficient are presented for the free surface flow of a thin liquid film adjacent to a horizontal rotating disk. The computation has been performed for different flow rates and rotational velocities using a three-dimensional boundary-fitted coordinate system. Since the geometry of the free surface is unknown and dependent on flow rate, rate of rotation, and other parameters, an interative procedure had to be used to ascertain its location. The computed film height agreed well with existing experimental measurements. The flow was dominated by inertia near the entrance and close to the free surface, and dominated by centrifugal force at larger radii and adjacent to the disk. The rotation enhanced the heat transfer coefficient by a significant amount.

  13. Strengthened lithium for x-ray blast windows

    SciTech Connect

    Pereira, N. R.; Imam, M. A.

    2008-05-15

    Lithium's high x-ray transparency makes it an attractive material for windows intended to protect soft x-ray diagnostics in high energy density experiments. Pure lithium is soft and weak, but lithium mixed with lithium hydride powder becomes harder and stronger, in principle without any additional x-ray absorption. A comparison with the standard material for x-ray windows, beryllium, suggests that lithium or lithium strengthened by lithium hydride may well be an excellent option for such windows.

  14. Strengthened lithium for x-ray blast windows.

    PubMed

    Pereira, N R; Imam, M A

    2008-05-01

    Lithium's high x-ray transparency makes it an attractive material for windows intended to protect soft x-ray diagnostics in high energy density experiments. Pure lithium is soft and weak, but lithium mixed with lithium hydride powder becomes harder and stronger, in principle without any additional x-ray absorption. A comparison with the standard material for x-ray windows, beryllium, suggests that lithium or lithium strengthened by lithium hydride may well be an excellent option for such windows.

  15. Calorimetry of 25 Ah lithium/thionyl chloride cells

    NASA Technical Reports Server (NTRS)

    Johnson, C. J.; Dawson, S.

    1991-01-01

    Heat flow measurements of 25-Ah lithium thionyl chloride cells provided a method to calculate an effective thermal potential, E(TP) of 3.907 V. The calculation is useful to determine specific heat generation of this cell chemistry and design. The E(TP) value includes heat generation by electrochemical cell reactions, competitive chemical reactions, and resistance heating at the tabs, connectors, and leads. Heat flow was measured while applying electrical loads to the cell in an isothermal calorimeter set at 0, 20, and 60 C.

  16. Lithium Diisopropylamide-Mediated Ortholithiations: Lithium Chloride Catalysis

    PubMed Central

    Gupta, Lekha; Hoepker, Alexander C.; Singh, Kanwal J.

    2009-01-01

    Ortholithiations of a range of arenes mediated by lithium diisopropylamide (LDA) in THF at -78 °C reveal substantial accelerations by as little as 0.5 mol % LiCl (relative to LDA). Substrate dependencies suggest a specific range of reactivity within which the LiCl catalysis is optimal. Standard protocols using unpurified commercial samples of n-butyllithium to prepare LDA or commercially available LDA show marked batch-dependent rates--up to 100-fold--that could prove significant to the unwary practitioner. Other lithium salts elicit more modest accelerations. The mechanism is not discussed. PMID:19191711

  17. Lithium metal oxide electrodes for lithium cells and batteries

    DOEpatents

    Thackeray, Michael M.; Johnson, Christopher S.; Amine, Khalil; Kim, Jaekook

    2004-01-13

    A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO.sub.2.(1-x)Li.sub.2 M'O.sub.3 in which 0

  18. Lithium metal oxide electrodes for lithium cells and batteries

    DOEpatents

    Thackeray, Michael M.; Johnson, Christopher S.; Amine, Khalil; Kim, Jaekook

    2006-11-14

    A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO.sub.2.(1-x)Li.sub.2M'O.sub.3 in which 0

  19. A simplified high figure-of-merit prism-free surface plasmon resonance refractive index sensor based on self adaptive angular interrogation.

    PubMed

    Lan, Guoqiang; Liu, Shugang; Zhang, Xueru; Wang, Yuxiao; Song, Yinglin

    2015-02-01

    We propose a simplified prism-free surface plasmon resonance (SPR) refractive index sensor based on self adaptive angular interrogation. An orthogonal V-shaped box with liquid sample is designed to achieve the functions of prism, sample cell, and mirror in a single setup. The rotator taking the self adaptive sample box is the sole mobile part in the system, which simplifies the structure greatly. A glass slide coated with Ag film is employed in this sample box as the sensing chip, in which the Ag film is isolated from the sample and air to prevent oxidation and pollution. According to the experimental results, the system can attain the figure-of-merit with 312.3/RIU, which is almost triple as high as that of the conventional prism-based sensor with the same samples. The proposed configuration could also be potentially utilized for the microminiaturization of the SPR sensor.

  20. Growth of Defect-Free 3C-Sic on 4H- and 6H-SIC Mesas Using Step-Free Surface Heteroepitaxy

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G.; Powell, J. Anthony; Trunek, Andrew J.; Huang, Xianrong R.; Dudley, Michael

    2002-01-01

    A new growth process, herein named step-free surface heteroepitaxy, has achieved 3C-SiC films completely free of double positioning boundaries and stacking faults on 4H-SiC and 6H-SiC substrate mesas. The process is based upon the initial 2-dimensional nucleation and lateral expansion of a single island of 3C-SiC on a 4H- or 6H-SiC mesa surface that is completely free of bilayer surface steps. Our experimental results indicate that substrate-epilayer in-plane lattice mismatch (Delta/a = 0.0854% for 3C/4H) is at least partially relieved parallel to the interface in the initial bilayers of the heterofilm, producing an at least partially relaxed 3C-SiC film without dislocations that undesirably thread through the thickness of the epilayer. This result should enable realization of improved 3C-SiC devices.