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Sample records for pjm nozzle configuration

  1. PJM Controller Testing with Prototypic PJM Nozzle Configuration

    SciTech Connect

    Bontha, Jagannadha R.; Nigl, Franz; Weier, Dennis R.; Leigh, Richard J.; Johnson, Eric D.; Wilcox, Wayne A.; Pfund, David M.; Baumann, Aaron W.; Wang, Yeefoo

    2009-08-21

    The U.S. Department of Energy (DOE) Office of River Protection’s Waste Treatment Plant (WTP) is being designed and built to pre-treat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks. The WTP consists of three primary facilities—pretreatment, low-activity waste (LAW) vitrification, and high-level waste (HLW) vitrification. The pretreatment facility will receive waste piped from the Hanford tank farms and separate it into a high-volume, low-activity liquid stream stripped of most solids and radionuclides and a much smaller volume of HLW slurry containing most of the solids and most of the radioactivity. Many of the vessels in the pretreatment facility will contain pulse jet mixers (PJM) that will provide some or all of the mixing in the vessels. Pulse jet mixer technology was selected for use in black cell regions of the WTP, where maintenance cannot be performed once hot testing and operations commence. The PJMs have no moving mechanical parts that require maintenance. The vessels with the most concentrated slurries will also be mixed with air spargers and/or steady jets in addition to the mixing provided by the PJMs. Pulse jet mixers are susceptible to overblows that can generate large hydrodynamic forces, forces that can damage mixing vessels or their internal parts. The probability of an overblow increases if a PJM does not fill completely. The purpose of the testing performed for this report was to determine how reliable and repeatable the primary and safety (or backup) PJM control systems are at detecting drive overblows (DOB) and charge vessel full (CVF) conditions. Testing was performed on the ABB 800xA and Triconex control systems. The controllers operated an array of four PJMs installed in an approximately 13 ft diameter × 15 ft tall tank located in the high bay of the Pacific Northwest National Laboratory (PNNL) 336 Building test facility. The PJMs were fitted with 4 inch diameter discharge nozzles

  2. Canard configured aircraft with 2-D nozzle

    NASA Technical Reports Server (NTRS)

    Child, R. D.; Henderson, W. P.

    1978-01-01

    A closely-coupled canard fighter with vectorable two-dimensional nozzle was designed for enhanced transonic maneuvering. The HiMAT maneuver goal of a sustained 8g turn at a free-stream Mach number of 0.9 and 30,000 feet was the primary design consideration. The aerodynamic design process was initiated with a linear theory optimization minimizing the zero percent suction drag including jet effects and refined with three-dimensional nonlinear potential flow techniques. Allowances were made for mutual interference and viscous effects. The design process to arrive at the resultant configuration is described, and the design of a powered 2-D nozzle model to be tested in the LRC 16-foot Propulsion Wind Tunnel is shown.

  3. Jet engine nozzle exit configurations and associated systems and methods

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G. (Inventor)

    2011-01-01

    Nozzle exit configurations and associated systems and methods are disclosed. An aircraft system in accordance with one embodiment includes a jet engine exhaust nozzle having an internal flow surface and an exit aperture, with the exit aperture having a perimeter that includes multiple projections extending in an aft direction. Aft portions of individual neighboring projections are spaced apart from each other by a gap, and a geometric feature of the multiple can change in a monotonic manner along at least a portion of the perimeter.

  4. Jet Engine Nozzle Exit Configurations and Associated Systems and Methods

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G. (Inventor)

    2013-01-01

    Nozzle exit configurations and associated systems and methods are disclosed. An aircraft system in accordance with one embodiment includes a jet engine exhaust nozzle having an internal flow surface and an exit aperture, with the exit aperture having a perimeter that includes multiple projections extending in an aft direction. Aft portions of individual neighboring projections are spaced apart from each other by a gap, and a geometric feature of the multiple can change in a monotonic manner along at least a portion of the perimeter.

  5. The effects of magnetic nozzle configurations on plasma thrusters

    NASA Technical Reports Server (NTRS)

    York, Thomas M.

    1990-01-01

    Plasma thrusters have been operated at power levels from 10 kw to 0.1 MW. When these devices have had magnetic fields applied to them which form a nozzle configuration for the expanding plasma, they have shown marked increases in exhaust velocity which is in direct proportion to the magnitude of the applied field. Further, recent results have shown that electrode erosion may be influenced by applied magnetic fields. This research effort is directed to the experimental and computational study of the effects of applied magnetic field nozzles in the acceleration of plasma flows. Plasma source devices which eliminate the plasma interaction in normal thrusters are studied as most basic. Normal thruster configurations were studied without applied fields and with applied magnetic nozzle fields. Unique computational studies utilize existing codes which accurately include transport processes. Unique diagnostic studies supported the experimental studies to generate new data. Both computation and diagnostics were combined to indicate the physical mechanisms and transport properties that are operative in order to allow scaling and accurate prediction of thruster performance.

  6. The effects of magnetic nozzle configurations on plasma thrusters

    NASA Technical Reports Server (NTRS)

    York, Thomas M.

    1989-01-01

    Plasma thrusters have been operated at power levels from 10kW to 0.1MW. When these devices have had magnetic fields applied to them which form a nozzle configuration for the expanding plasma, they have shown marked increases in exhaust velocity which is in direct proportion to the magnitude of the applied field. Further, recent results have shown that electrode erosion may be influenced by applied magnetic fields. This research is directed to the experimental and computational study of the effects of applied magnetic field nozzles in the acceleration of plasma flows. Plasma source devices which eliminate the plasma interaction in normal thrusters are studied as most basic. Normal thruster configurations will be studied without applied fields and with applied magnetic nozzle fields. Unique computational studies will utilize existing codes which accurately include transport processes. Unique diagnostic studies will support the experimental studies to generate new data. Both computation and diagnostics will be combined to indicate the physical mechanisms and transport properties that are operative in order to allow scaling and accurate prediction of thruster performance.

  7. Effect of injector configuration in rocket nozzle film cooling

    NASA Astrophysics Data System (ADS)

    Kumar, A. Lakshya; Pisharady, J. C.; Shine, S. R.

    2016-04-01

    Experimental and numerical investigations are carried out to analyze the effect of coolant injector configuration on overall film cooling performance in a divergent section of a rocket nozzle. Two different injector orientations are investigated: (1) shaped slots with a divergence angle of 15° (semi-divergent injector) (2) fully divergent slot (fully divergent injector). A 2-dimensional, axis-symmetric, multispecies computational model using finite volume formulation has been developed and validated against the experimental data. The experiments provided a consistent set of measurements for cooling effectiveness for different blowing ratios ranging from 3.7 to 6. Results show that the semi divergent configuration leads to higher effectiveness compared to fully divergent slot at all blowing ratios. The spatially averaged effectiveness results show that the difference between the two configurations is significant at higher blowing ratios. The increase in effectiveness was around 2 % at BR = 3.7 whereas it was around 12 % in the case of BR = 6. Numerical results show the presence of secondary flow recirculation zones near the jet exit for both the injectors. An additional recirculation zone present in the case of fully divergent injector caused an increase in mixing of the coolant and mainstream, and a reduction in film cooling performance.

  8. Noise tests of a model engine-over-the-wing STOL configuration using a multijet nozzle with deflector

    NASA Technical Reports Server (NTRS)

    Olsen, W. A.; Friedman, R.

    1973-01-01

    Noise data were obtained with a small scale model stationary STOL configuration that used an eight lobe mixer nozzle with deflector mounted above a 32-cm-chord wing section. The factors varied to determine their effect upon the noise were wing flap angle, nozzle shape, nozzle location, deflector configuration, and jet velocity. The noise from the mixer nozzle model was compared to the noise from a model using a circular nozzle of the same area. The mixer nozzle model was quieter at the low to middle frequencies, while the circular nozzle was quieter at high frequencies. The perceived noise level (PNL) was calculated for an aircraft 10 times larger than the model. The PNL at 500 feet for the mixer nozzle turned out to be within 1 db of the PNL for the circular nozzle. For some configurations at highly directional broadband noise, which could be eliminated by changes in nozzle and/or deflector location, occurred below the wing.

  9. Analysis of Plume Effects on Sonic Boom Signature for Isolated Nozzle Configurations

    NASA Technical Reports Server (NTRS)

    Castner, Raymond S.

    2008-01-01

    Computational fluid dynamics (CFD) analysis has been performed to study the plume effects on sonic boom signature for isolated nozzle configurations. The objectives of these analyses were to provide comparison to past work using modern CFD analysis tools, to investigate the differences of high aspect ratio nozzles to circular (axisymmetric) nozzles, and to report the effects of underexpanded nozzle operation on boom signature. CFD analysis was used to address the plume effects on sonic boom signature from a baseline exhaust nozzle. Near-field pressure signatures were collected for nozzle pressure ratios (NPRs) between 6 and 10. A computer code was used to extrapolate these signatures to a ground-observed sonic boom N-wave. Trends show that there is a reduction in sonic boom N-wave signature as NPR is increased from 6 to 10. The performance curve for this supersonic nozzle is flat, so there is not a significant loss in thrust coefficient as the NPR is increased. As a result, this benefit could be realized without significant loss of performance. Analyses were also collected for a high aspect ratio nozzle based on the baseline design for comparison. Pressure signatures were collected for nozzle pressure ratios from 8 to 12. Signatures were nearly twice as strong for the two-dimensional case, and trends also show a reduction in sonic boom signature as NPR is increased from 8 to 12. As low boom designs are developed and improved, there will be a need for understanding the interaction between the aircraft boat tail shocks and the exhaust nozzle plume. These CFD analyses will provide a baseline study for future analysis efforts.

  10. Jet engine nozzle exit configurations, including projections oriented relative to pylons, and associated systems and methods

    NASA Technical Reports Server (NTRS)

    Mengle, Vinod G. (Inventor); Thomas, Russell H. (Inventor)

    2012-01-01

    Nozzle exit configurations and associated systems and methods are disclosed. An aircraft system in accordance with one embodiment includes a jet engine exhaust nozzle having an internal flow surface and an exit aperture, with the exit aperture having a perimeter that includes multiple projections extending in an aft direction. Aft portions of individual neighboring projections are spaced apart from each other by a gap, and a geometric feature of the multiple can change in a monotonic manner along at least a portion of the perimeter. Projections near a support pylon and/or associated heat shield can have particular configurations, including greater flow immersion than other projections.

  11. Experimental study of jet surface structures and the influence of nozzle configuration

    NASA Astrophysics Data System (ADS)

    Gong, Chen; Yang, Minguan; Kang, Can; Wang, Yuli

    2016-08-01

    Under the three breakup regimes, the jet surface waves of different nozzles are captured and measured. The nozzles have different length to diameter ratios and contraction angles. The measured wavelengths are compared with the reported conclusions which were obtained by using spatial and temporal linear stability analysis. The results show that the jet wavelengths of different breakup regimes are covered by a single curve when the wavelengths are non-dimensionalized with boundary layer thickness. For the nozzle with equal length and diameter, the entire translation section starts at Re = 3 × 104 and ends at Re = 4.5 × 104. The wavelength non-dimensionalized with boundary layer thickness is independent of nozzle configuration. The ratio of initial wavelength to boundary layer thickness ranges from 2 to 4.

  12. Jet-Pylon Interaction of High Bypass Ratio Separate Flow Nozzle Configurations

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Kinzie, Kevin W.

    2004-01-01

    NASA Langley Research Center, Hampton, Virginia, 23681-0001 USA An experimental investigation was performed of the acoustic effects of jet-pylon interaction for separate flow and chevron nozzles of both bypass ratio five and eight. The models corresponded to an approximate scale factor of nine. Cycle conditions from approach to takeoff were tested at wind tunnel free jet Mach numbers of 0.1, 0.2 and 0.28. An eight-chevron core nozzle, a sixteen chevron fan nozzle, and a pylon were primary configuration variables. In addition, two orientations of the chevrons relative to each other and to the pylon were tested. The effect of the pylon on the azimuthal directivity was investigated for the baseline nozzles and the chevron nozzles. For the bypass ratio five configuration, the addition of the pylon reduces the noise by approximately 1 EPNdB compared to the baseline case and there is little effect of azimuthal angle. The core chevron produced a 1.8 EPNdB reduction compared to the baseline nozzle. Adding a pylon to the chevron core nozzle produces an effect that depends on the orientation of the chevron relative to the pylon. The azimuthal directivity variation remains low at less than 0.5 EPNdB. For the bypass ratio eight configuration the effect of adding a pylon to the baseline nozzle is to slightly increase the noise at higher cycle points and for the case with a core chevron the pylon has little additional effect. The azimuthal angle effect continues to be very small for the bypass ratio eight configurations. A general impact of the pylon was observed for both fan and core chevrons at both bypass ratios. The pylon reduces the typical low frequency benefit of the chevrons, even eliminating it in some cases, while not impacting the high frequency. On an equal ideal thrust basis, the bypass ratio eight baseline nozzle was about 5 EPNdB lower than the bypass ratio five baseline nozzle at the highest cycle condition, however, with a pylon installed the difference

  13. Development of an Integrated Nozzle for a Symmetric, RBCC Launch Vehicle Configuration

    NASA Technical Reports Server (NTRS)

    Smith, Timothy D.; Canabal, Francisco, III; Rice, Tharen; Blaha, Bernard

    2000-01-01

    The development of rocket based combined cycle (RBCC) engines is highly dependent upon integrating several different modes of operation into a single system. One of the key components to develop acceptable performance levels through each mode of operation is the nozzle. It must be highly integrated to serve the expansion processes of both rocket and air-breathing modes without undue weight, drag, or complexity. The NASA GTX configuration requires a fixed geometry, altitude-compensating nozzle configuration. The initial configuration, used mainly to estimate weight and cooling requirements was a 1 So half-angle cone, which cuts a concave surface from a point within the flowpath to the vehicle trailing edge. Results of 3-D CFD calculations on this geometry are presented. To address the critical issues associated with integrated, fixed geometry, multimode nozzle development, the GTX team has initiated a series of tasks to evolve the nozzle design, and validate performance levels. An overview of these tasks is given. The first element is a design activity to develop tools for integration of efficient expansion surfaces With the existing flowpath and vehicle aft-body, and to develop a second-generation nozzle design. A preliminary result using a "streamline-tracing" technique is presented. As the nozzle design evolves, a combination of 3-D CFD analysis and experimental evaluation will be used to validate the design procedure and determine the installed performance for propulsion cycle modeling. The initial experimental effort will consist of cold-flow experiments designed to validate the general trends of the streamline-tracing methodology and anchor the CFD analysis. Experiments will also be conducted to simulate nozzle performance during each mode of operation. As the design matures, hot-fire tests will be conducted to refine performance estimates and anchor more sophisticated reacting-flow analysis.

  14. Nozzle

    DOEpatents

    Chen, Alexander G.; Cohen, Jeffrey M.

    2009-06-16

    A fuel injector has a number of groups of nozzles. The groups are generally concentric with an injector axis. Each nozzle defines a gas flowpath having an outlet for discharging a fuel/air mixture jet. There are means for introducing the fuel to the air. One or more groups of the nozzles are oriented to direct the associated jets skew to the injector axis.

  15. The Effects of Magnetic Nozzle Configurations on Plasma Thrusters

    NASA Technical Reports Server (NTRS)

    Turchi, P. J.

    1997-01-01

    Over the course of eight years, the Ohio State University has performed research in support of electric propulsion development efforts at the NASA Lewis Research Center, Cleveland, OH. This research has been largely devoted to plasma propulsion systems including MagnetoPlasmaDynamic (MPD) thrusters with externally-applied, solenoidal magnetic fields, hollow cathodes, and Pulsed Plasma Microthrusters (PPT's). Both experimental and theoretical work has been performed, as documented in four master's theses, two doctoral dissertations, and numerous technical papers. The present document is the final report for the grant period 5 December 1987 to 31 December 1995, and summarizes all activities. Detailed discussions of each area of activity are provided in appendices: Appendix 1 - Experimental studies of magnetic nozzle effects on plasma thrusters; Appendix 2 - Numerical modeling of applied-field MPD thrusters; Appendix 3 - Theoretical and experimental studies of hollow cathodes; and Appendix 4 -Theoretical, numerical and experimental studies of pulsed plasma thrusters. Especially notable results include the efficacy of using a solenoidal magnetic field downstream of a plasma thruster to collimate the exhaust flow, the development of a new understanding of applied-field MPD thrusters (based on experimentally-validated results from state-of-the art, numerical simulation) leading to predictions of improved performance, an experimentally-validated, first-principles model for orificed, hollow-cathode behavior, and the first time-dependent, two-dimensional calculations of ablation-fed, pulsed plasma thrusters.

  16. 76 FR 39870 - PJM Interconnection, LLC; PJM Power Providers Group v. PJM Interconnection, LLC; Notice of Date...

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    2011-07-07

    ... Energy Regulatory Commission PJM Interconnection, LLC; PJM Power Providers Group v. PJM Interconnection... applicability of the PJM Interconnection, LLC (PJM) Minimum Offer Price Rule (MOPR) as it relates to self-supply... base residual auction.\\2\\ \\1\\ PJM Interconnection, LLC, 135 FERC ] 61,022 (2011). \\2\\...

  17. Effects of Nozzle Configuration on Flow Characteristics inside DC Plasma Torch

    NASA Astrophysics Data System (ADS)

    Yuan, X. Q.; Li, H.; Zhao, T. Z.; Guo, W. K.; Xu, P.

    2004-10-01

    The effects of nozzle configuration on the characteristics of flow inside DC arc plasma torches are investigated by numerical simulation. The plasma torches with three typical types of nozzle configuration are used in this paper, and these torches are the SG-100 series commercial products of PRAXAIR Thermal Spray Products Inc. The assumption of steady-state, axis-symmetric, local thermodynamic equilibrium, and optically thin plasma is adopted in a two-dimensional modeling of plasma flow inside a plasma torch. The PHOENICS software is used for solving the governing equations, i.e., the conservation equations of mass, momentum, and energy. The calculated arc voltages are consistent with the experimental results when arc current, gas inflow rate, and working gas are the same. Temperature, axial velocity contours inside the plasma torches, and profiles along the torch axis and at the outlet section are presented to show the plasma flow characteristics. Comparisons are made among these torches in detail and the results show that torches with different anode nozzle configurations produce different characteristic plasma flows.

  18. Assessment at full scale of nozzle/wing geometry effects on OTW aeroacoustic characteristics. [Over The Wing STOL engine configurations

    NASA Technical Reports Server (NTRS)

    Groesbeck, D.; Von Glahn, U.

    1979-01-01

    The effects on acoustic characteristics of nozzle type and location on a wing for STOL engine over-the-wing configurations are assessed at full scale on the basis of model-scale data. Three types of nozzle configurations are evaluated: a circular nozzle with external deflector mounted above the wing, a slot nozzle with external deflector mounted on the wing and a slot nozzle mounted on the wing. Nozzle exhaust plane locations with respect to the wing leading edge are varied from 10 to 46 percent chord (flaps retracted) with flap angles of 20 deg (take-off attitude) and 60 deg (approach attitude). Perceived noise levels (PNL) are calculated as a function of flyover distance at 152 m altitude. From these plots, static EPNL values, defined as flyover relative noise levels, are calculated and plotted as a function of lift and thrust ratios. From such plots the acoustic benefits attributable to variations in nozzle/deflector/wing geometry at full scale are assessed for equal aerodynamic performance.

  19. Planning for environmental constraints on the PJM system

    SciTech Connect

    Not Available

    1994-07-15

    This chapter provides a snapshot of the existing PJM system and identifies the environmental constraints that form the parameters for the regional approaches analyzed in this study. The chapter begins with a description of the PJM system and the costs and emissions levels of the pollutants under study associated with the reference case (the PJM system configured to meet only Clean Air Act Amendment Phase I SO{sub 2} requirements and the March 1994 NO{sub x} requirements affecting Phase I units){sup 3}. Next, the pollution-reduction scenario assumed for the purpose of the study, which covers the period 1995--2010, is described. Finally, the impacts of this pollution reduction scenario -- emissions that would need to be avoided on the reference case PJM system -- are identified. Modeling methods are described alongside the study`s results. Other chapters discuss: environmental constraints, alternate plans to achieve environmental goals, and comparison of alternate plans.

  20. Effect of nozzle tip configuration on the micro-droplet formation.

    PubMed

    Kim, Byung-Jae; Hwang, In-Ju; Kim, Youn-Jea

    2013-12-01

    Micro-droplet formation is an emerging area of research due to its wide-ranging applications in micro-fluidic based devices. For high resolution patterning and coating processes in various industrial fields, the formation of micro-droplets should be controlled according to the rheological properties of the working fluids. However, the physical properties of the some of working fluids are limited to meet the industrial applications. In this paper, the effect of the nozzle tip configuration on the micro-droplet formation process was numerically observed. A two-phase level-set modeling method was employed for simulations, and the results for various nozzle shapes were compared. In order to validate the numerical results of ink-jet printing with various operating conditions, we introduced a dimensionless parameter Z which is the factor of correlation of dynamic viscosity with surface tension of a working fluid on the microfluidics of drop-on-demand (DOD) jets, and obtained reasonable values of Z. Also, the numerical results such as velocity and shear rate distributions, etc. were graphically depicted in two-dimensional coordinates.

  1. A Grid-resolved Analysis of Base Flowfield for a Four-Engine Clustered Nozzle Configuration

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See

    1993-01-01

    The objective of this study is to propose a computational methodology that can effectively anchor the base flowfield of a four-engine clustered nozzle configuration. This computational methodology is based on a three-dimensional, viscous flow, pressure-based computational fluid dynamics (CFD) formulation. For efficient CFD calculation, a Prandtl-Meyer solution treatment is applied to the algebraic grid lines for initial plume expansion resolution. As the solution evolves, the computational grid is adapted to the pertinent flow gradients. The CFD model employs an upwind scheme in which second- and fourth-order central differencing schemes with artificial dissipation are used. The computed quantitative base flow properties such as the radial base pressure distributions, model centerline static pressure, Mach number and impact pressure variations, and base pressure characteristic curve agreed reasonably well with those of the measurement.

  2. Static and Wind Tunnel Aero-Performance Tests of NASA AST Separate Flow Nozzle Noise Reduction Configurations

    NASA Technical Reports Server (NTRS)

    Mikkelsen, Kevin L.; McDonald, Timothy J.; Saiyed, Naseem (Technical Monitor)

    2001-01-01

    This report presents the results of cold flow model tests to determine the static and wind tunnel performance of several NASA AST separate flow nozzle noise reduction configurations. The tests were conducted by Aero Systems Engineering, Inc., for NASA Glenn Research Center. The tests were performed in the Channels 14 and 6 static thrust stands and the Channel 10 transonic wind tunnel at the FluiDyne Aerodynamics Laboratory in Plymouth, Minnesota. Facility checkout tests were made using standard ASME long-radius metering nozzles. These tests demonstrated facility data accuracy at flow conditions similar to the model tests. Channel 14 static tests reported here consisted of 21 ASME nozzle facility checkout tests and 57 static model performance tests (including 22 at no charge). Fan nozzle pressure ratio varied from 1.4 to 2.0, and fan to core total pressure ratio varied from 1.0 to 1.19. Core to fan total temperature ratio was 1.0. Channel 10 wind tunnel tests consisted of 15 tests at Mach number 0.28 and 31 tests at Mach 0.8. The sting was checked out statically in Channel 6 before the wind tunnel tests. In the Channel 6 facility, 12 ASME nozzle data points were taken and 7 model data points were taken. In the wind tunnel, fan nozzle pressure ratio varied from 1.73 to 2.8, and fan to core total pressure ratio varied from 1.0 to 1.19. Core to fan total temperature ratio was 1.0. Test results include thrust coefficients, thrust vector angle, core and fan nozzle discharge coefficients, total pressure and temperature charging station profiles, and boat-tail static pressure distributions in the wind tunnel.

  3. 76 FR 45248 - PJM Interconnection, L.L.C., PJM Power Providers Group v. PJM Interconnection, L.L.C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... Energy Regulatory Commission PJM Interconnection, L.L.C., PJM Power Providers Group v. PJM Interconnection, L.L.C.; Supplemental Notice of Staff Technical Conference On June 13, 2011, the Commission issued... Resources Services, Inc., Maryland Public Service Commission, Monitoring Analytics, L.L.C., National...

  4. Numerical Analysis of Base Flowfield for a Four-Engine Clustered Nozzle Configuration

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See

    1995-01-01

    Excessive base heating has been a problem for many launch vehicles. For certain designs such as the direct dump of turbine exhaust inside and at the lip of the nozzle, the potential burning of the turbine exhaust in the base region can be of great concern. Accurate prediction of the base environment at altitudes is therefore very important during the vehicle design phase. Otherwise, undesirable consequences may occur. In this study, the turbulent base flowfield of a cold flow experimental investigation for a four-engine clustered nozzle was numerically benchmarked using a pressure-based computational fluid dynamics (CFD) method. This is a necessary step before the benchmarking of hot flow and combustion flow tests can be considered. Since the medium was unheated air, reasonable prediction of the base pressure distribution at high altitude was the main goal. Several physical phenomena pertaining to the multiengine clustered nozzle base flow physics were deduced from the analysis.

  5. Numerical investigation of unsteady flow development in a nozzle-duct configuration

    NASA Technical Reports Server (NTRS)

    Li, C. P.

    1983-01-01

    A computational approach has been used to resolve the transient phenomena caused by a rocket engine starting up and exhausting into a short duct. The results are obtained from the finite-difference Navier-Stokes, continuity, and energy equations for a single component gas. Using a recently developed numerical technique to account for the time-varying boundary conditions at the nozzle throat and the duct openings, the numerical simulation of the idealized ignition flow model has yielded some insight into the complex interactions between the wave patterns and the vortical flow. The present findings verify the hypothesis that a lateral expansion of the jetstream outside the nozzle will generate an over-pressure pulse on the duct wall if the jetstream is restricted within the nozzle by flow separation. The numerical simulations of this complex flow problem should be useful for improving simple correlation techniques used for engineering purposes.

  6. 76 FR 46793 - PJM Interconnection, L.L.C.; PJM Power Providers Group v. PJM Interconnection, L.L.C.; Notice...

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    2011-08-03

    ... Energy Regulatory Commission PJM Interconnection, L.L.C.; PJM Power Providers Group v. PJM Interconnection, L.L.C.; Notice Establishing Post-Technical Comment Period As indicated in the June 29, 2011... issues related to PJM Interconnection, L.L.C. (PJM)'s Minimum Offer Price Rule (MOPR) and...

  7. Multiaxis thrust vectoring using axisymmetric nozzles and postexit vanes on an F/A-18 configuration vehicle

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.; Noffz, Gregory K.; Grafton, Sue B.; Mason, Mary L.; Peron, Lee R.

    1991-01-01

    A ground-based investigation was conducted on an operational system of multiaxis thrust vectoring using postexit vanes around an axisymmetric nozzle. This thrust vectoring system will be tested on the NASA F/A-18 High Alpha Research Vehicle (HARV) aircraft. The system provides thrust vectoring capability in both pitch and yaw. Ground based data were gathered from two separate tests at NASA Langley Research Center. The first was a static test in the 16-foot Transonic Tunnel Cold-Jet Facility with a 14.25 percent scale model of the axisymmetric nozzle and the postexit vanes. The second test was conducted in the 30 by 60 foot wind tunnel with a 16 percent F/A-18 complete configuration model. Data from the two sets are being used to develop models of jet plume deflection and thrust loss as a function of vane deflection. In addition, an aerodynamic interaction model based on plume deflection angles will be developed. Results from the scale model nozzle test showed that increased vane deflection caused exhaust plume turning. Aerodynamic interaction effects consisted primarily of favorable interaction of moments and unfavorable interaction of forces caused by the vectored jet plume.

  8. Evaluation of scramjet nozzle configurations and film cooling for reduction of wall heating

    NASA Technical Reports Server (NTRS)

    Baker, N. R.; Northam, G. B.; Stouffer, S. D.; Capriotti, D. P.

    1993-01-01

    Experiments on relaminarization, or reverse transition of turbulent flow, have been conducted with a scramjet combustor and nozzle model. The Mach-2.7 direct-connect scramjet combustor employed swept-ramp fuel injectors, and the entering flow simulated Mach-6 to Mach-7 flight conditions. Tests were also conducted without combustor fuel to produce a higher nozzle entrance Mach number and lower pressures. Additional tests were conducted to evaluate the effectiveness of film cooling on the cowl region. At each test condition studied, the entrance radius had no significant effect on the measured downstream wall heating rates. Analysis of the data when fuel was injected into the combustor shows good agreement with turbulent theory; for the tests without fuel injection and combustion, the data downstream of the nozzle entrance radius are intermediate to the calculated turbulent and laminar solutions. Results of film-cooling tests, conducted with both hydrogen and nitrogen injectants, showed that, per unit mass, the hydrogen was approximately three to four times more effective than nitrogen in reducing the downstream wall heating rates.

  9. Numerical study of base pressure characteristic curve for a four-engine clustered nozzle configuration

    NASA Astrophysics Data System (ADS)

    Wang, Ten-See

    1993-07-01

    Excessive base heating has been a problem for many launch vehicles. For certain designs such as the direct dump of turbine exhaust in the nozzle section and at the nozzle lip of the Space Transportation Systems Engine (STME), the potential burning of the turbine exhaust in the base region has caused tremendous concern. Two conventional approaches have been considered for predicting the base environment: (1) empirical approach, and (2) experimental approach. The empirical approach uses a combination of data correlations and semi-theoretical calculations. It works best for linear problems, simple physics and geometry. However, it is highly suspicious when complex geometry and flow physics are involved, especially when the subject is out of historical database. The experimental approach is often used to establish database for engineering analysis. However, it is qualitative at best for base flow problems. Other criticisms include the inability to simulate forebody boundary layer correctly, the interference effect from tunnel walls, and the inability to scale all pertinent parameters. Furthermore, there is a contention that the information extrapolated from subscale tests with combustion is not conservative. One potential alternative to the conventional methods is computational fluid dynamics (CFD), which has none of the above restrictions and is becoming more feasible due to maturing algorithms and advancing computer technology. It provides more details of the flowfield and is only limited by computer resources. However, it has its share of criticisms as a predictive tool for base environment. One major concern is that CFD has not been extensively tested for base flow problems. It is therefore imperative that CFD be assessed and benchmarked satisfactorily for base flows. In this study, the turbulent base flowfield of a experimental investigation for a four-engine clustered nozzle is numerically benchmarked using a pressure based CFD method. Since the cold air was the

  10. 77 FR 9225 - Allegheny Electric Cooperative, Inc., et al. v. PJM Interconnection, L.L.C.; Organization of PJM...

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    2012-02-16

    ... Energy Regulatory Commission Allegheny Electric Cooperative, Inc., et al. v. PJM Interconnection, L.L.C.; Organization of PJM States, Inc., et al. v. PJM Interconnection, L.L.C.; Notice of Filing Take notice that on... required by section 18.17.4 of the Amended and Restated Operating Agreement of PJM Interconnection,...

  11. 76 FR 7836 - PJM Power Providers Group v. PJM Interconnection, L.L.C.; Notice of Complaint

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    2011-02-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Power Providers Group v. PJM Interconnection, L.L.C.; Notice of... 385.206, PJM Power Providers Group (Complainant) filed a formal complaint against PJM...

  12. Simplified configuration for the combustor of an oil burner using a low pressure, high flow air-atomizing nozzle

    DOEpatents

    Butcher, Thomas A.; Celebi, Yusuf; Fisher, Leonard

    2000-09-15

    The invention relates to clean burning of fuel oil with air. More specifically, to a fuel burning combustion head using a low-pressure, high air flow atomizing nozzle so that there will be a complete combustion of oil resulting in a minimum emission of pollutants. The improved fuel burner uses a low pressure air atomizing nozzle that does not result in the use of additional compressors or the introduction of pressurized gases downstream, nor does it require a complex design. Inventors:

  13. Simplified Configuration for the Combustor of an oil Burner using a low Pressure, high flow air-atomizing Nozzle

    SciTech Connect

    Butcher, Thomas; Celebi, Yusuf; Fisher, Leonard

    1998-09-28

    The invention relates to clean burning of fuel oil with air. More specifically, to a fuel burning combustion head using a low-pressure, high air flow atomizing nozzle so that there will be a complete combustion oil resulting in a minimum emission of pollutants. The inventors have devised a fuel burner that uses a low pressure air atomizing nozzle. The improved fuel burner does not result in the use of additional compressors or the introduction of pressurized gases downstream, nor does it require a complex design.

  14. Effect of exhaust nozzle configuration on aerodynamic and acoustic performance of an externally blown flap system with a quiet 6:1 bypass ratio engine

    NASA Technical Reports Server (NTRS)

    Samanich, N. E.; Heidelberg, L. J.; Jones, W. L.

    1973-01-01

    A highly suppressed TF-34 engine was used to investigate engine and flap interaction noise associated with an externally blown flap STOL powered lift system. Noise, efficiency, and velocity decay characteristics of mixed and separate flow exhaust systems including convergent, co-annular, and lobed designs were determined with the engine operating alone. Noise data were then obtained for several of the exhaust configurations with the engine blowing a wing-flap segment. Noise for both the engine alone and the engine with blown flaps showed substantial differences for the various exhaust configurations tested. The differences in observed noise are related primarily to nozzle effective exhaust velocity, flap impingement velocity, and noise spectral shape.

  15. Measured and predicted impingement noise for a model-scale under the wing externally blown flap configuration with a QCSEE type nozzle

    NASA Technical Reports Server (NTRS)

    Mckinzie, D. J., Jr.

    1980-01-01

    Jet/flap interaction noise was measured and predicted for a small-scale model two-flap, under-the-wing, externally blown flap configuration equipped with and without noise suppression devices. The devices consisted of short spanwise fairings centered in relationship to the jet axis and positioned in the slots between the wing and flaps. The nozzle approximated that of the Quiet Clean Short-haul Experimental Engine (QCSEE). Takeoff noise reductions of 6 dB in the flyover and 5 dB in the sideline plane were obtained over a wide range of radiation angles. Approach noise reductions of about 5 dB were obtained only in the forward quadrant of the flyover plane; no reductions were obtained in the sideline plane. Models of several noise sources were combined analytically to form an overall noise prediction, the results from which compared favorably with the measured data. The aerodynamic performance characteristics for these configurations were substantially the same in the takeoff attitude. However, in the approach attitude, the suppressed configuration produced a 6 percent reduction in the flow turning efficiency.

  16. Inlet nozzle assembly

    DOEpatents

    Christiansen, David W.; Karnesky, Richard A.; Precechtel, Donald R.; Smith, Bob G.; Knight, Ronald C.

    1987-01-01

    An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

  17. Inlet nozzle assembly

    DOEpatents

    Christiansen, D.W.; Karnesky, R.A.; Knight, R.C.; Precechtel, D.R.; Smith, B.G.

    1985-09-09

    An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

  18. 77 FR 3766 - PJM Interconnection, L.L.C.; Notice of Staff Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ... Energy Regulatory Commission PJM Interconnection, L.L.C.; Notice of Staff Technical Conference On... explore the issues presented by PJM Interconnection, L.L.C.'s (PJM) filing.\\1\\ Take notice that the... Commission's questions by February 10, 2012. \\1\\ PJM Interconnection, L.L.C., 137 FERC ] 61,204...

  19. 76 FR 16405 - Notice of Attendance at PJM INterconnection, L.L.C., Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-23

    ... Energy Regulatory Commission Notice of Attendance at PJM INterconnection, L.L.C., Meetings The Federal... Commission staff may attend upcoming PJM Interconnection, L.L.C., (PJM) meetings, as well as other... proceedings before the Commission including the following: Docket No. EL05-121, PJM Interconnection,...

  20. 75 FR 40815 - PJM Interconnection, L.L.C.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ... Energy Regulatory Commission PJM Interconnection, L.L.C.; Notice of Filing July 7, 2010. Take notice that on July 1, 2010, PJM Interconnection, L.L.C. (PJM) filed revised sheets to Schedule 1 of the Amended and Restated Operating Agreement of PJM Interconnection, L.L.C. (Operating Agreement) and the...

  1. Stepped nozzle

    DOEpatents

    Sutton, George P.

    1998-01-01

    An insert which allows a supersonic nozzle of a rocket propulsion system to operate at two or more different nozzle area ratios. This provides an improved vehicle flight performance or increased payload. The insert has significant advantages over existing devices for increasing nozzle area ratios. The insert is temporarily fastened by a simple retaining mechanism to the aft end of the diverging segment of the nozzle and provides for a multi-step variation of nozzle area ratio. When mounted in place, the insert provides the nozzle with a low nozzle area ratio. During flight, the retaining mechanism is released and the insert ejected thereby providing a high nozzle area ratio in the diverging nozzle segment.

  2. Stepped nozzle

    DOEpatents

    Sutton, G.P.

    1998-07-14

    An insert is described which allows a supersonic nozzle of a rocket propulsion system to operate at two or more different nozzle area ratios. This provides an improved vehicle flight performance or increased payload. The insert has significant advantages over existing devices for increasing nozzle area ratios. The insert is temporarily fastened by a simple retaining mechanism to the aft end of the diverging segment of the nozzle and provides for a multi-step variation of nozzle area ratio. When mounted in place, the insert provides the nozzle with a low nozzle area ratio. During flight, the retaining mechanism is released and the insert ejected thereby providing a high nozzle area ratio in the diverging nozzle segment. 5 figs.

  3. Arcjet Nozzle Design Impacts

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Sovie, Amy J.; Haag, Thomas W.

    1989-01-01

    The effect of nozzle configuration on the operating characteristics of a low power dc arcjet thruster was determined. A conical nozzle with a 30 deg converging angle, a 20 deg diverging angle, and an area ratio of 225 served as the baseline case. Variations on the geometry included bell-shaped contours both up and downstream, and a downstream trumpet-shaped contour. The nozzles were operated over a range of specific power near that anticipated for on-orbit operation. Mass flow rate, thrust, current, and voltage were monitored to provide accurate comparisons between nozzles. The upstream contour was found to have minimal effect on arcjet operation. It was determined that the contour of the divergent section of the nozzle, that serves as the anode, was very important in determining the location of arc attachment, and thus had a significant impact on arcjet performance. The conical nozzle was judged to have the optimal current/voltage characteristics and produced the best performance of the nozzles tested.

  4. Turbine nozzle/nozzle support structure

    DOEpatents

    Boyd, Gary L.; Shaffer, James E.

    1995-01-01

    An axial flow turbine's nozzle/nozzle support structure having a cantilevered nozzle outer structure including an outer shroud and airfoil vanes extending radially inwardly therefrom, an inner shroud radially adjacent the inner end of the airfoil vanes and cooperatively disposed relative to the outer shroud to provide an annular fluid flow path, an inner and an outer support ring respectively arranged radially inside the inner shroud and axially adjacent a portion of the outer shroud, and pins extending through such portion and into the outer support ring. The inner support ring or inner shroud has a groove therein bounded by end walls for receiving and being axially abuttable with a locating projection from the adjacent airfoil vane, inner shroud, or inner support ring. The nozzle outer structure may comprise segments each of which has a single protrusion which is axially engageable with the outer support ring or, alternatively, a first and second protrusion which are arcuately and axially separated and which include axial openings therein whereby first and second protrusions on respective, arcuately adjacent nozzle segments have axial openings therein which are alignable with connector openings in the outer support ring and within each of such aligned openings a pin is receivable. The inner shroud may, likewise, comprise segments which, when assembled in operating configuration, have a 360 degree expanse.

  5. Turbine nozzle/nozzle support structure

    DOEpatents

    Boyd, Gary L.; Shaffer, James E.

    1996-01-01

    An axial flow turbine's nozzle/nozzle support structure having a cantilevered nozzle outer structure including an outer shroud and airfoil vanes extending radially inwardly therefrom, an inner shroud radially adjacent the inner end of the airfoil vanes and cooperatively disposed relative to the outer shroud to provide an annular fluid flow path, an inner and an outer support ring respectively arranged radially inside the inner shroud and axially adjacent a portion of the outer shroud, and pins extending through such portion and into the outer support ring. The inner support ring or inner shroud has a groove therein bounded by end walls for receiving and being axially abuttable with a locating projection from the adjacent airfoil vane, inner shroud, or inner support ring. The nozzle outer structure may comprise segments each of which has a single protrusion which is axially engageable with the outer support ring or, alternatively, a first and second protrusion which are arcuately and axially separated and which include axial openings therein whereby first and second protrusions on respective, arcuately adjacent nozzle segments have axial openings therein which are alignable with connector openings in the outer support ring and within each of such aligned openings a pin is receivable. The inner shroud may, likewise, comprise segments which, when assembled in operating configuration, have a 360 degree expanse.

  6. Turbine nozzle/nozzle support structure

    DOEpatents

    Boyd, Gary L.; Shaffer, James E.

    1997-01-01

    An axial flow turbine's nozzle/nozzle support structure having a cantilevered nozzle outer structure including an outer shroud and airfoil vanes extending radially inwardly therefrom, an inner shroud radially adjacent the inner end of the airfoil vanes and cooperatively disposed relative to the outer shroud to provide an annular fluid flow path, an inner and an outer support ring respectively arranged radially inside the inner shroud and axially adjacent a portion of the outer shroud, and pins extending through such portion and into the outer support ring. The inner support ring or inner shroud has a groove therein bounded by end walls for receiving and being axially abuttable with a locating projection from the adjacent airfoil vane, inner shroud, or inner support ring. The nozzle outer structure may comprise segments each of which has a single protrusion which is axially engageable with the outer support ring or, alternatively, a first and second protrusion which are arcuately and axially separated and which include axial openings therein whereby first and second protrusions on respective, arcuately adjacent nozzle segments have axial openings therein which are alignable with connector openings in the outer support ring and within each of such aligned openings a pin is receivable. The inner shroud may, likewise, comprise segments which, when assembled in operating configuration, have a 360 degree expanse.

  7. Turbine nozzle/nozzle support structure

    DOEpatents

    Boyd, G.L.; Shaffer, J.E.

    1997-01-07

    An axial flow turbine`s nozzle/nozzle support structure is described having a cantilevered nozzle outer structure including an outer shroud and airfoil vanes extending radially inwardly therefrom, an inner shroud radially adjacent the inner end of the airfoil vanes and cooperatively disposed relative to the outer shroud to provide an annular fluid flow path, an inner and an outer support ring respectively arranged radially inside the inner shroud and axially adjacent a portion of the outer shroud, and pins extending through such portion and into the outer support ring. The inner support ring or inner shroud has a groove therein bounded by end walls for receiving and being axially abuttable with a locating projection from the adjacent airfoil vane, inner shroud, or inner support ring. The nozzle outer structure may comprise segments each of which has a single protrusion which is axially engageable with the outer support ring or, alternatively, a first and second protrusion which are arcuately and axially separated and which include axial openings therein whereby first and second protrusions on respective, arcuately adjacent nozzle segments have axial openings therein which are alignable with connector openings in the outer support ring and within each of such aligned openings a pin is receivable. The inner shroud may, likewise, comprise segments which, when assembled in operating configuration, have a 360 degree expanse. 6 figs.

  8. Turbine nozzle/nozzle support structure

    DOEpatents

    Boyd, G.L.; Shaffer, J.E.

    1996-09-10

    An axial flow turbine`s nozzle/nozzle support structure is described having a cantilevered nozzle outer structure including an outer shroud and airfoil vanes extending radially inwardly therefrom, an inner shroud radially adjacent the inner end of the airfoil vanes and cooperatively disposed relative to the outer shroud to provide an annular fluid flow path, an inner and an outer support ring respectively arranged radially inside the inner shroud and axially adjacent a portion of the outer shroud, and pins extending through such portion and into the outer support ring. The inner support ring or inner shroud has a groove therein bounded by end walls for receiving and being axially abuttable with a locating projection from the adjacent airfoil vane, inner shroud, or inner support ring. The nozzle outer structure may comprise segments each of which has a single protrusion which is axially engageable with the outer support ring or, alternatively, a first and second protrusion which are arcuately and axially separated and which include axial openings therein whereby first and second protrusions on respective, arcuately adjacent nozzle segments have axial openings therein which are alignable with connector openings in the outer support ring and within each of such aligned openings a pin is receivable. The inner shroud may, likewise, comprise segments which, when assembled in operating configuration, have a 360 degree expanse. 6 figs.

  9. Turbine nozzle/nozzle support structure

    DOEpatents

    Boyd, G.L.; Shaffer, J.E.

    1995-08-15

    An axial flow turbine`s nozzle/nozzle support structure is described having a cantilevered nozzle outer structure including an outer shroud and airfoil vanes extending radially inwardly therefrom, an inner shroud radially adjacent the inner end of the airfoil vanes and cooperatively disposed relative to the outer shroud to provide an annular fluid flow path, an inner and an outer support ring respectively arranged radially inside the inner shroud and axially adjacent a portion of the outer shroud, and pins extending through such portion and into the outer support ring. The inner support ring or inner shroud has a groove therein bounded by end walls for receiving and being axially abuttable with a locating projection from the adjacent airfoil vane, inner shroud, or inner support ring. The nozzle outer structure may comprise segments each of which has a single protrusion which is axially engageable with the outer support ring or, alternatively, a first and second protrusion which are arcuately and axially separated and which include axial openings therein whereby first and second protrusions on respective, arcuately adjacent nozzle segments have axial openings therein which are alignable with connector openings in the outer support ring and within each of such aligned openings a pin is receivable. The inner shroud may, likewise, comprise segments which, when assembled in operating configuration, have a 360 degree expanse. 6 figs.

  10. Effects of spanwise nozzle geometry and location on the longitudinal aerodynamic characteristics of a vectored-engine-over-wing configuration at subsonic speeds

    NASA Technical Reports Server (NTRS)

    Leavitt, L. D.; Yip, L. P.

    1978-01-01

    A V/STOL tunnel study was performed to determine the effects of spanwise blowing on longitudinal aerodynamic characteristics of a model using a vectored-over-wing powered lift concept. The effects of spanwise nozzle throat area, internal and external nozzle geometry, and vertical and axial location were investigated. These effects were studied at a Mach number of 0.186 over an angle-of-attack range from 14 deg to 40 deg. A high pressure air system was used to provide jet-exhaust simulation. Engine nozzle pressure ratio was varied from 1.0 (jet off) to approximately 3.75.

  11. Turbomachine combustor nozzle including a monolithic nozzle component and method of forming the same

    DOEpatents

    Stoia, Lucas John; Melton, Patrick Benedict; Johnson, Thomas Edward; Stevenson, Christian Xavier; Vanselow, John Drake; Westmoreland, James Harold

    2016-02-23

    A turbomachine combustor nozzle includes a monolithic nozzle component having a plate element and a plurality of nozzle elements. Each of the plurality of nozzle elements includes a first end extending from the plate element to a second end. The plate element and plurality of nozzle elements are formed as a unitary component. A plate member is joined with the nozzle component. The plate member includes an outer edge that defines first and second surfaces and a plurality of openings extending between the first and second surfaces. The plurality of openings are configured and disposed to register with and receive the second end of corresponding ones of the plurality of nozzle elements.

  12. Linear nozzle with tailored gas plumes

    DOEpatents

    Kozarek, Robert L.; Straub, William D.; Fischer, Joern E.; Leon, David D.

    2003-01-01

    There is claimed a method for depositing fluid material from a linear nozzle in a substantially uniform manner across and along a surface. The method includes directing gaseous medium through said nozzle to provide a gaseous stream at the nozzle exit that entrains fluid material supplied to the nozzle, said gaseous stream being provided with a velocity profile across the nozzle width that compensates for the gaseous medium's tendency to assume an axisymmetric configuration after leaving the nozzle and before reaching the surface. There is also claimed a nozzle divided into respective side-by-side zones, or preferably chambers, through which a gaseous stream can be delivered in various velocity profiles across the width of said nozzle to compensate for the tendency of this gaseous medium to assume an axisymmetric configuration.

  13. Linear nozzle with tailored gas plumes

    DOEpatents

    Leon, David D.; Kozarek, Robert L.; Mansour, Adel; Chigier, Norman

    2001-01-01

    There is claimed a method for depositing fluid material from a linear nozzle in a substantially uniform manner across and along a surface. The method includes directing gaseous medium through said nozzle to provide a gaseous stream at the nozzle exit that entrains fluid material supplied to the nozzle, said gaseous stream being provided with a velocity profile across the nozzle width that compensates for the gaseous medium's tendency to assume an axisymmetric configuration after leaving the nozzle and before reaching the surface. There is also claimed a nozzle divided into respective side-by-side zones, or preferably chambers, through which a gaseous stream can be delivered in various velocity profiles across the width of said nozzle to compensate for the tendency of this gaseous medium to assume an axisymmetric configuration.

  14. Progress toward synergistic hypermixing nozzles

    NASA Technical Reports Server (NTRS)

    Davis, D. O.; Hingst, W. R.

    1991-01-01

    Mean flow measurements were obtained for air-to-air mixing downstream of swept and unswept ramp wall mounted hypermixing nozzle configurations. Aside from the sweep of the ramps, the two nozzle configurations studied are identical. The nozzles inject three parallel supersonic jets at a 15 deg angle (relative to the wind tunnel wall) into a supersonic freestream. Mach number and volume fraction distributions in a transverse plane 11.1 nozzle heights downstream from the nozzle exit plane were measured. Data are presented for a freestream Mach number of three at a matched static pressure condition and also at underexpanded static pressure condition (pressure ratio = 5). Surface oil flow visualization was used to study the near wall flow behavior. The results indicate that the swept ramp injectors produce stronger and larger vortex pairs than the unswept ramp injectors. The increased interaction between the swept ramp model's larger vortex pairs yields better mixing characteristics for this model.

  15. Experimental characterization of spin motor nozzle flow.

    SciTech Connect

    Erven, Rocky J.; Peterson, Carl Williams; Henfling, John Francis

    2006-11-01

    The Mach number in the inviscid core of the flow exiting scarfed supersonic nozzles was measured using pitot probes. Nozzle characterization experiments were conducted in a modified section of an obsolete M = 7.3 test section/nozzle assembly on Sandia's Hypersonic Wind Tunnel. By capitalizing on existing hardware, the cost and time required for tunnel modifications were significantly reduced. Repeatability of pitot pressure measurements was excellent, and instrumentation errors were reduced by optimizing the pressure range of the transducers used for each test run. Bias errors in probe position prevented us from performing a successful in situ calibration of probe angle effects using pitot probes placed at an angle to the nozzle centerline. The abrupt throat geometry used in the Baseline and Configuration A and B nozzles modeled the throat geometry of the flight vehicle's spin motor nozzles. Survey data indicates that small (''unmeasurable'') differences in the nozzle throat geometries produced measurable flow asymmetries and differences in the flow fields generated by supposedly identical nozzles. Therefore, data from the Baseline and Configuration A and B nozzles cannot be used for computational fluid dynamics (CFD) code validation. Configuration C and D nozzles replaced the abrupt throat geometry of Baseline and Configuration A and B nozzles with a 0.500-inch streamwise radius of curvature in the throat region. This throat geometry eliminated the flow asymmetries, flow separation in the nozzle throat, and measurable differences between the flow fields from identical nozzles that were observed in Baseline/A/B nozzles. Data from Configuration C and D nozzles can be used for CFD code validation.

  16. 77 FR 37032 - Capacity Deliverability Across the Midwest; Independent Transmission System Operator, Inc.; PJM...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-20

    ... Operator, Inc.; PJM Interconnection, L.L.C. Seam; Notice Establishing Comment Period On June 11, 2012, the... Independent Transmission System Operator, Inc./PJM Interconnection, L.L.C. Seam.'' 139 FERC 61,200...

  17. 75 FR 32458 - Virginia Electric and Power Company v. PJM Interconnection, LLC; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Virginia Electric and Power Company v. PJM Interconnection, LLC; Notice of... Power Company (Complainant) filed a formal complaint against PJM Interconnection, LLC...

  18. 75 FR 16449 - Central Transmission, LLC v. PJM Interconnection L.L.C.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Central Transmission, LLC v. PJM Interconnection L.L.C.; Notice of Complaint...) filed a complaint against the PJM Interconnection L.L.C. (PJM) pursuant to section 206 of the...

  19. 78 FR 21928 - Demand Response Coalition v. PJM Interconnection, L.L.C.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Demand Response Coalition v. PJM Interconnection, L.L.C.; Notice of... formal complaint against the PJM Interconnection, L.L.C. (Respondent or PJM), alleging that certain...

  20. 77 FR 34378 - PJM Interconnection, L.L.C.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-11

    ... Energy Regulatory Commission PJM Interconnection, L.L.C.; Notice of Complaint Take notice that on June 1, 2012, pursuant to section 206 of the Federal Power Act (FPA), 16 U.S.C. 824(e), PJM Interconnection, L.L.C. (PJM) filed proposed revisions to the Amended and Restated Operating Agreement of...

  1. 75 FR 22773 - PJM Interconnection, L.L.C.; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-30

    ... Energy Regulatory Commission PJM Interconnection, L.L.C.; Notice of Filing April 23, 2010. Take notice that on April 22, 2010, PJM Interconnection, L.L.C. (PJM) filed revised tariff sheets to its Schedule 1... Interconnection, L.L.C., 130 FERC ] 61,230 (2010). Any person desiring to intervene or to protest this filing...

  2. 78 FR 19259 - Notice of Attendance at PJM Interconnection, L.L.C. Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-29

    ... Energy Regulatory Commission Notice of Attendance at PJM Interconnection, L.L.C. Meetings The Federal... Commission staff may attend upcoming PJM Interconnection, L.L.C. (PJM) Members Committee and Markets and... Interconnection, L.L.C. Docket No. EL08-14, Black Oak Energy LLC, et al., v. FERC Docket No. EL10-52,...

  3. 77 FR 30002 - Primary Power, LLC v. PJM Interconnection, LLC; Notice of Complaint

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    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Primary Power, LLC v. PJM Interconnection, LLC; Notice of Complaint Take... against PJM Interconnection, LLC (PJM or Respondent) for the Respondent's failure to designate...

  4. 75 FR 20590 - PJM Interconnection, L.L.C., Complainant, v. Midwest Independent Transmission, System Operator...

    Federal Register 2010, 2011, 2012, 2013, 2014

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    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Interconnection, L.L.C., Complainant, v. Midwest Independent....S.C. 824(e), 825(e) and 825(h), PJM Interconnection, L.L.C. (PJM or Complainant) filed a...

  5. 78 FR 57374 - Northern Indiana Public Service Company v. Midcontinent Independent System Operator, Inc., PJM...

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    ... against Midcontinent Independent System Operator, Inc. (MISO) and PJM Interconnection, L.L.C. (PJM... Energy Regulatory Commission Northern Indiana Public Service Company v. Midcontinent Independent System Operator, Inc., PJM Interconnection, L.L.C.; Notice of Complaint Take notice that on September 11,...

  6. Nozzle seal

    DOEpatents

    Herman, Richard Frederick

    1977-10-25

    In an illustrative embodiment of the invention, a nuclear reactor pressure vessel, having an internal hoop from which the heated coolant emerges from the reactor core and passes through to the reactor outlet nozzles, is provided with sealing members operatively disposed between the outlet nozzle and the hoop. The sealing members are biased against the pressure vessel and the hoop and are connected by a leak restraining member establishing a leak-proof condition between the inlet and outlet coolants in the region about the outlet nozzle. Furthermore, the flexible responsiveness of the seal assures that the seal will not structurally couple the hoop to the pressure vessel.

  7. 76 FR 12954 - PPL EnergyPlus, LLC v. PJM Interconnection, L.L.C.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PPL EnergyPlus, LLC v. PJM Interconnection, L.L.C.; Notice of Complaint Take... formal complaint against PJM Interconnection, L.L.C. (PJM or Respondent), alleging that PJM failed...

  8. Nozzle development

    SciTech Connect

    Dodge, F.T.; Dodge, L.G.; Johnson, J.E.

    1989-06-01

    The objective of this program has been the development of experimental techniques and data processing procedures to allow for the characterization of multi-phase fuel nozzles using laboratory tests. Test results were to be used to produce a single value coefficient-of-performance that would predict the performance of the fuel nozzles independent of system application. Several different types of fuel nozzles capable of handling multi-phase fuels have been characterized for: (a) fuel flow rate versus delivery pressure, (b) fuel-air ratio throughout the fuel spray or plume and the effective cone angle of the injector, and (c) fuel drop- or particle-size distribution as a function of fluid properties. Fuel nozzles which have been characterized on both single-phase liquids and multi-phase liquid-solid slurries include a variable-film-thickness nozzle, a commercial coal-water slurry (CWS) nozzle, and four diesel injectors of different geometries (tested on single-phase fluids only). Multi-phase mixtures includes CWS with various coal loadings, surfactant concentrations, and stabilizer concentrations, as well as glass-bead water slurries with stabilizing additives. Single-phase fluids included glycerol-water mixtures to vary the viscosity over a range of 1 to 1500 cP, and alcohol-water mixtures to vary the surface tension from about 22 to 73 dyne/cm. In addition, tests were performed to characterize straight-tube gas-solid nozzles using two differences size distributions of glass beads in air. Standardized procedures have been developed for processing measurements of spray drop-size characteristics and the overall cross-section average drop or particle size. 43 refs., 60 figs., 7 tabs.

  9. Nozzle seal

    DOEpatents

    Groff, Russell Dennis; Vatovec, Richard John

    1978-06-11

    In an illustrative embodiment of the invention, a nuclear reactor pressure vessel, having an internal hoop from which the heated coolant emerges from the reactor core and passes through to the reactor outlet nozzles, is provided with annular sealing members operatively disposed between the outlet nozzle and the hoop and partly within a retaining annulus formed in the hoop. The sealing members are biased against the pressure vessel and the hoop and one of the sealing members is provided with a piston type pressure ring sealing member which effectively closes the path between the inlet and outlet coolants in the region about the outlet nozzle establishing a leak-proof condition. Furthermore, the flexible responsiveness of the seal assures that the seal will not structurally couple the hoop to the pressure vessel.

  10. Focusing liquid microjets with nozzles

    NASA Astrophysics Data System (ADS)

    Acero, A. J.; Ferrera, C.; Montanero, J. M.; Gañán-Calvo, A. M.

    2012-06-01

    The stability of flow focusing taking place in a converging-diverging nozzle, as well as the size of the resulting microjets, is examined experimentally in this paper. The results obtained in most aspects of the problem are similar to those of the classical plate-orifice configuration. There is, however, a notable difference between flow focusing in nozzles and in the plate-orifice configuration. In the former case, the liquid meniscus oscillates laterally (global whipping) for a significant area of the control parameter plane, a phenomenon never observed when focusing with the plate-orifice configuration. Global whipping may constitute an important drawback of flow focusing with nozzles because it reduces the robustness of the technique.

  11. The whistler nozzle phenomenon

    NASA Technical Reports Server (NTRS)

    Hussain, A. K. M. F.; Hasan, M. A. Z.

    1982-01-01

    The whistler nozzle is a simple device which can induce jet self-excitations of controllable amplitudes and frequencies and appears highly promising for many applications involving turbulent transport, combustion and aerodynamic noise. The characteristics of this curious phenomenon are documented for different values of the controlling parameters and attempts to explain the phenomenon. It is shown that the whistler excitation results from the coupling of two independent resonance mechanisms: shear-layer tone resulting from the impingement of the pipe-exit shear layer on the collar lip, and organ-pipe resonance of the pipe-nozzle. The crucial role of the shear-layer tone in driving the organ-pipe resonance is proven by reproducing the event in pipe-ring and pipe-hole configurations in the absence of the collar. It is also shown that this phenomenon is the strongest when the self-excitation frequency matches the preferred mode of the jet.

  12. 77 FR 10505 - Notice of Attendance at PJM Interconnection, L.L.C. Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-22

    ... Energy Regulatory Commission Notice of Attendance at PJM Interconnection, L.L.C. Meetings The Federal... Commission staff may attend upcoming PJM Interconnection, L.L.C. (PJM) Members Committee meetings, as well as..., L.L.C. Docket Nos. ER06-456, ER06-880, ER06-954, ER06-1271, EL07-57, ER07-424, ER07-1186,...

  13. Forced Mixer Nozzle Optimization

    NASA Technical Reports Server (NTRS)

    Sheoran, Yogi; Hoover, Robert; Schuster, William; Anderson, Morris; Weir, Donald S.

    1999-01-01

    Computational fluid dynamic (CFD) and computational acoustic analyses (CAA) were performed for a TFE731-40 compound nozzle, a TFE731-60 mixer nozzle and an Energy Efficient Engine (E(sup 3)) mixer nozzle for comparison with available data. The CFD analyses were performed with a three dimensional, Navier-Stokes solution of the flowfield on an unstructured grid using the RAMPANT program. The CAA analyses were performed with the NASA Glenn MGB program using a structured grid. A successful aerodynamic solution for the TFE731-40 compound nozzle operating statically was obtained, simulating an engine operating on a test stand. Analysis of the CFD results of the TFE731-40 with the MGB program produced predicted sound power levels that agree quite well with the measured data front full-scale static engine tests. Comparison of the predicted sound pressure with the data show good agreement near the jet axis, but the noise levels are overpredicted at angles closer to the inlet. The predicted sound power level for the TFE731-60 did not agree as well with measured static engine data as the TFE731-40. Although a reduction in the predicted noise level due to the mixed flow was observed, the reduction was not as significant as the measured data. The analysis of the V2 mixer from the E(sup 3) study showed that peak temperatures predicted in the mixer exit flowfield were within 5 percent of the values measured by the exit probes. The noise predictions of the V2 mixer nozzle tended to be 3-5 dB higher in peak noise level than the measurements. In addition, the maximum frequency of the noise was also overpredicted. An analysis of the 3 candidate mixer nozzle configurations demonstrated the feasibility of using centerbody lobes and porosity to improve mixing efficiency. A final configuration was designed with a predicted thermal mixing efficiency that was 5 percent higher than the 3 candidate mixers. The results of the MGB noise calculations show that the final design will exceed the

  14. Sandblasting nozzle

    NASA Technical Reports Server (NTRS)

    Perkins, G. S.; Pawlik, E. V.; Phillips, W. M. (Inventor)

    1981-01-01

    A nozzle for use with abrasive and/or corrosive materials is formed of sintered ceramic compositions having high temperature oxidation resistance, high hardness and high abrasion and corrosion resistance. The ceramic may be a binary solid solution of a ceramic oxide and silicon nitride, and preferably a ternary solid solution of a ceramic oxide, silicon nitride and aluminum nitride. The ceramic oxide is selected from a group consisting of Al2O3, Y2O3 and Cr2O3, or mixtures of those compounds. Titanium carbide particles are dispersed in the ceramic mixture before sintering. The nozzles are encased for protection from external forces while in use by a metal or plastic casing.

  15. Flame tolerant secondary fuel nozzle

    SciTech Connect

    Khan, Abdul Rafey; Ziminsky, Willy Steve; Wu, Chunyang; Zuo, Baifang; Stevenson, Christian Xavier

    2015-02-24

    A combustor for a gas turbine engine includes a plurality of primary nozzles configured to diffuse or premix fuel into an air flow through the combustor; and a secondary nozzle configured to premix fuel with the air flow. Each premixing nozzle includes a center body, at least one vane, a burner tube provided around the center body, at least two cooling passages, a fuel cooling passage to cool surfaces of the center body and the at least one vane, and an air cooling passage to cool a wall of the burner tube. The cooling passages prevent the walls of the center body, the vane(s), and the burner tube from overheating during flame holding events.

  16. Linear nozzle with tailored gas plumes and method

    DOEpatents

    Leon, David D.; Kozarek, Robert L.; Mansour, Adel; Chigier, Norman

    1999-01-01

    There is claimed a method for depositing fluid material from a linear nozzle in a substantially uniform manner across and along a surface. The method includes directing gaseous medium through said nozzle to provide a gaseous stream at the nozzle exit that entrains fluid material supplied to the nozzle, said gaseous stream being provided with a velocity profile across the nozzle width that compensates for the gaseous medium's tendency to assume an axisymmetric configuration after leaving the nozzle and before reaching the surface. There is also claimed a nozzle divided into respective side-by-side zones, or preferably chambers, through which a gaseous stream can be delivered in various velocity profiles across the width of said nozzle to compensate for the tendency of this gaseous medium to assume an axisymmetric configuration.

  17. Splitting supersonic nozzle flow into separate jets by overexpansion into a multilobed divergent nozzle

    NASA Technical Reports Server (NTRS)

    Huff, R. G.; Groesbeck, D. E.

    1972-01-01

    Air flowing from a convergent nozzle at pressure ratios greater than 2.5 has been split into eight separate jets by overexpansion of the flow into a divergent, eight-lobed passage. The splitting of the flow is accompanied by a decrease in the nozzle axial centerline Mach number. This in part is due to the radial inflow of secondary air between the lobes toward the nozzle centerline. Each of the smaller jets is partially split after it leaves the end of the divergent lobed section of the nozzle, thus creating a velocity profile having 16 peaks. At a pressure ratio of 3.5 the flow decelerates to Mach 1 in three convergent nozzle throat diameters. Convergent nozzle flow normally requires 12 diameters to reach Mach 1. The nozzle has a sound attenuation of 12 decibels with a thrust loss of 9 percent for the best configuration tested.

  18. Performance characteristics of a one-third-scale, vectorable ventral nozzle for SSTOVL aircraft

    NASA Technical Reports Server (NTRS)

    Esker, Barbara S.; Mcardle, Jack G.

    1990-01-01

    Several proposed configurations for supersonic short takeoff, vertical landing aircraft will require one or more ventral nozzles for lift and pitch control. The swivel nozzle is one possible ventral nozzle configuration. A swivel nozzle (approximately one-third scale) was built and tested on a generic model tailpipe. This nozzle was capable of vectoring the flow up to + or - 23 deg from the vertical position. Steady-state performance data were obtained at pressure ratios to 4.5, and pitot-pressure surveys of the nozzle exit plane were made. Two configurations were tested: the swivel nozzle with a square contour of the leading edge of the ventral duct inlet, and the same nozzle with a round leading edge contour. The swivel nozzle showed good performance overall, and the round-leading edge configuration showed an improvement in performance over the square-leading edge configuration.

  19. 77 FR 20019 - FirstEnergy Solutions Corp., Allegheny Energy Supply Company, LLC v. PJM Interconnection, L.L.C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... Interconnection, L.L.C.; Notice of Complaint Take notice that on March 26, 2012, pursuant to sections 206 and 306... formal complaint against PJM Interconnection, L.L.C. (PJM) (Respondent) alleging that provisions of...

  20. Fuel nozzle assembly

    DOEpatents

    Johnson, Thomas Edward; Ziminsky, Willy Steve; Lacey, Benjamin Paul; York, William David; Stevenson, Christian Xavier

    2011-08-30

    A fuel nozzle assembly is provided. The assembly includes an outer nozzle body having a first end and a second end and at least one inner nozzle tube having a first end and a second end. One of the nozzle body or nozzle tube includes a fuel plenum and a fuel passage extending therefrom, while the other of the nozzle body or nozzle tube includes a fuel injection hole slidably aligned with the fuel passage to form a fuel flow path therebetween at an interface between the body and the tube. The nozzle body and the nozzle tube are fixed against relative movement at the first ends of the nozzle body and nozzle tube, enabling the fuel flow path to close at the interface due to thermal growth after a flame enters the nozzle tube.

  1. 77 FR 16218 - Notice of Petition for Declaratory Order: PJM Interconnection, L.L.C.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-20

    ... responsibility under its tariffs to oversee worker safety in maintenance operations performed by employees of the Transmission Owners (TOs), and (2) the bar to ordinary negligence claims set forth in PJM's Open Access Transmission Tariff applies when PJM executes its Regional Transmission Organization functions of planning...

  2. 75 FR 45626 - PJM Interconnection, L.L.C.; Notice of Petition for Declaratory Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Interconnection, L.L.C.; Notice of Petition for Declaratory Order July... Commission's (Commission) Rules of Practice and Procedure (18 CFR 385.207), PJM Interconnection, L.L.C....

  3. 78 FR 62360 - PJM Interconnection, L.L.C.; Notice of Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Interconnection, L.L.C.; Notice of Technical Conference Federal Energy.... to approximately 1:00 p.m., to consider issues related to PJM Interconnection, L.L.C.'s...

  4. 76 FR 72699 - PJM Interconnection, LLC; Notice of Petition for Declaratory Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Interconnection, LLC; Notice of Petition for Declaratory Order Take... Federal Energy Regulatory Commission (Commission), 18 CFR 385.207(a)(2) (2011), PJM Interconnection,...

  5. 78 FR 41392 - Indicated Load-Serving Entities v. Midcontinent Independent System Operator, Inc. and PJM...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-10

    ... Energy Regulatory Commission Indicated Load-Serving Entities v. Midcontinent Independent System Operator... Indicated Load-Serving Entities, (Indicated LSEs or Complainants) within the Midcontinent Independent System Operator, Inc. (MISO) filed a formal complaint against MISO and PJM Interconnection, L.L.C. (PJM...

  6. 76 FR 37808 - PJM Interconnection, L.L.C.; Notice of Discussion Topics for Staff Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Interconnection, L.L.C.; Notice of Discussion Topics for Staff Technical... suspended proposed tariff changes submitted by PJM Interconnection, L.L.C. (PJM), subject to refund and...

  7. 76 FR 20655 - American Electric Power Service Corporation v. PJM Interconnection, L.L.C.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ... Energy Regulatory Commission American Electric Power Service Corporation v. PJM Interconnection, L.L.C... (Complainant) filed a formal complaint against PJM Interconnection, L.L.C. (Respondent), alleging that Schedule 8.1, section D.8 to the PJM Interconnection, L.L.C. Reliability Assurance Agreement is...

  8. 75 FR 40815 - Black Oak Energy, LLC, EPIC Merchant Energy, LP, SESCO Enterprises, LLC v. PJM Interconnection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    .... PJM Interconnection, LLC; Notice of Filing July 8, 2010. Take notice that on June 1, 2010, PJM Interconnection, LLC filed a report of refund pursuant to the Federal Energy Regulatory Commission's (Commission... Oak Energy, LLC, et al. v. PJM Interconnection, LLC, 131 FERC ] 61,024 (2010) (April 15 Order)....

  9. Geologic nozzles

    USGS Publications Warehouse

    Werner, Kieffer S.

    1989-01-01

    The importance of the low characteristic velocities of geologic fluids has not been widely recognized, and as a result, the importance of supercritical and supersonic flow in geological processes has generally been underestimated. The lateral blast at Mount St. Helens, Washington, propelled a gas heavily laden with dust into the atmosphere. Because of the low sound speed in this gas (about 100 m/s), the flow was internally supersonic. Old Faithful Geyser, Wyoming, is a converging-diverging nozzle in which liquid water refilling the conduit during the recharge cycle changes during eruption into a two-phase liquid-vapor mixture with a very low sound velocity. The high sound speed of liquid water determines the characteristics of harmonic tremor observed at the geyser during the recharge interval, whereas the low sound speed of the liquid-vapor mixture influences the fluid flow characteristics of the eruption. At the rapids of the Colorado River in the Grand Canyon, Arizona, the channel is constricted into the shape of a converging-diverging nozzle by the debris flows that enter from tributary canyons. Both subcritical and supercritical flow occur within the rapids. -from Author

  10. Convoluted nozzle design for the RL10 derivative 2B engine

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The convoluted nozzle is a conventional refractory metal nozzle extension that is formed with a portion of the nozzle convoluted to show the extendible nozzle within the length of the rocket engine. The convoluted nozzle (CN) was deployed by a system of four gas driven actuators. For spacecraft applications the optimum CN may be self-deployed by internal pressure retained, during deployment, by a jettisonable exit closure. The convoluted nozzle is included in a study of extendible nozzles for the RL10 Engine Derivative 2B for use in an early orbit transfer vehicle (OTV). Four extendible nozzle configurations for the RL10-2B engine were evaluated. Three configurations of the two position nozzle were studied including a hydrogen dump cooled metal nozzle and radiation cooled nozzles of refractory metal and carbon/carbon composite construction respectively.

  11. Gas only nozzle

    DOEpatents

    Bechtel, William Theodore; Fitts, David Orus; DeLeonardo, Guy Wayne

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozzle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  12. Combustor nozzle for a fuel-flexible combustion system

    DOEpatents

    Haynes, Joel Meier; Mosbacher, David Matthew; Janssen, Jonathan Sebastian; Iyer, Venkatraman Ananthakrishnan

    2011-03-22

    A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

  13. Alternate nozzle ablative materials program

    NASA Technical Reports Server (NTRS)

    Kimmel, N. A.

    1984-01-01

    Four subscale solid rocket motor tests were conducted successfully to evaluate alternate nozzle liner, insulation, and exit cone structural overwrap components for possible application to the Space Shuttle Solid Rocket Motor (SRM) nozzle asasembly. The 10,000 lb propellant motor tests were simulated, as close as practical, the configuration and operational environment of the full scale SRM. Fifteen PAN based and three pitch based materials had no filler in the phenolic resin, four PAN based materials had carbon microballoons in the resin, and the rest of the materials had carbon powder in the resin. Three nozzle insulation materials were evaluated; an aluminum oxide silicon oxide ceramic fiber mat phenolic material with no resin filler and two E-glass fiber mat phenolic materials with no resin filler. It was concluded by MTI/WD (the fabricator and evaluator of the test nozzles) and NASA-MSFC that it was possible to design an alternate material full scale SRM nozzle assembly, which could provide an estimated 360 lb increased payload capability for Space Shuttle launches over that obtainable with the current qualified SRM design.

  14. DSMC simulation of low Reynolds number nozzle flows

    NASA Technical Reports Server (NTRS)

    Zelesnik, D.; Micci, M. M.; Long, L. N.

    1993-01-01

    A numerical analysis of low Reynolds number nozzle flows was performed to investigate the loss mechanisms involved and to determine the nozzle wall contour that minimizes these losses. DSMC was used to simulate flows through three different nozzle configurations at two different stagnation chamber temperatures so that the heat transfer losses could be separated from the wall contour effects on performance. A trumpet-shaped nozzle had 5 percent higher efficiency than a conical nozzle and a 3 percent higher efficiency than a bell-shaped nozzle with the unheated flow. With heated flow both the trumpet and bell-shaped nozzles had a 6.5 percent higher efficiency than the conical nozzle. The conical nozzle had the highest discharge coefficient of the three configurations, 0.92, and the trumpet-shaped nozzle had the lowest, 0.82. The discharge coefficient of each nozzle was unaffected by the change in stagnation temperature; however the increase in stagnation temperature increased the heat transfer and viscous losses in the boundary layer. These results suggest that the trumpet-shaped wall contour performed most efficiently except near the throat region, where it incurred large viscous losses. However, the bell-shaped nozzle may increase its overall performance with an increase in stagnation temperature.

  15. Tests of a D vented thrust deflecting nozzle behind a simulated turbofan engine

    NASA Technical Reports Server (NTRS)

    Watson, T. L.

    1982-01-01

    A D vented thrust deflecting nozzle applicable to subsonic V/STOL aircraft was tested behind a simulated turbofan engine in the verticle thrust stand. Nozzle thrust, fan operating characteristics, nozzle entrance conditions, and static pressures were measured. Nozzle performance was measured for variations in exit area and thrust deflection angle. Six core nozzle configurations, the effect of core exit axial location, mismatched core and fan stream nozzle pressure ratios, and yaw vane presence were evaluated. Core nozzle configuration affected performance at normal and engine out operating conditions. Highest vectored nozzle performance resulted for a given exit area when core and fan stream pressure were equal. Its is concluded that high nozzle performance can be maintained at both normal and engine out conditions through control of the nozzle entrance Mach number with a variable exit area.

  16. One- and Two-Phase Nozzle Flows

    SciTech Connect

    Chang, I-Shih

    1980-12-01

    A time-dependent technique, in conjunction with the boundary-fitted coordinates system, is applied to solve a gas-only one-phase flow and a fully-coupled, gas-particle two-phase flow inside nozzles with small throat radii of curvature, steep wall gradients, and submerged configurations. The emphasis of the study has been placed on one- and two-phase flow in the transonic region. Various particle sizes and particle mass fractions have been investigated in the two-phase flow. The salient features associated with the two-phase nozzle flow compared with those of the one-phase flow are illustrated through the calculations of the JPL nozzle, the Titan III solid rocket motor, and the submerged nozzle configuration found in the Inertial Upper Stage (IUS) solid rocket motor.

  17. FINAL REPORT - HYBRID-MIXING TESTS SUPPORTING THE CONCENTRATE RECEIPT VESSEL (CRV-VSL-00002A/2B) CONFIGURATION

    SciTech Connect

    GUERRERO, HECTORN.

    2004-09-01

    The Savannah River National Laboratory (SRNL) has performed scaled physical modeling of Pulse Jet Mixing Systems applicable to the Concentrate Receipt Vessel (CRV) of Hanford's Waste Treatment Plant (WTP) as part of the overall effort to validate pulse jet mixer (PJM) mixing in WTP vessels containing non-Newtonian fluids. The strategy developed by the Pulse Jet Mixing Task Team was to construct a quarter-scale model of the CRV, use a clear simulant to understand PJM mixing behavior, and down-select from a number of PJM configurations to a ''best design'' configuration. This ''best design'' would undergo final validation testing using a particulate simulant that has rheological properties closely similar to WTP waste streams. The scaled PJM mixing tests were to provide information on the operating parameters critical for the uniform movement (total mobilization) of these non-Newtonian slurries. Overall, 107 tests were performed during Phase I and Phase II testing.

  18. Dual nozzle aerodynamic and cooling analysis study

    NASA Technical Reports Server (NTRS)

    Meagher, G. M.

    1981-01-01

    Analytical models to predict performance and operating characteristics of dual nozzle concepts were developed and improved. Aerodynamic models are available to define flow characteristics and bleed requirements for both the dual throat and dual expander concepts. Advanced analytical techniques were utilized to provide quantitative estimates of the bleed flow, boundary layer, and shock effects within dual nozzle engines. Thermal analyses were performed to define cooling requirements for baseline configurations, and special studies of unique dual nozzle cooling problems defined feasible means of achieving adequate cooling.

  19. Nozzle airfoil having movable nozzle ribs

    DOEpatents

    Yu, Yufeng Phillip; Itzel, Gary Michael

    2002-01-01

    A nozzle vane or airfoil structure is provided in which the nozzle ribs are connected to the side walls of the vane or airfoil in such a way that the ribs provide the requisite mechanical support between the concave side and convex side of the airfoil but are not locked in the radial direction of the assembly, longitudinally of the airfoil. The ribs may be bi-cast onto a preformed airfoil side wall structure or fastened to the airfoil by an interlocking slide connection and/or welding. By attaching the nozzle ribs to the nozzle airfoil metal in such a way that allows play longitudinally of the airfoil, the temperature difference induced radial thermal stresses at the nozzle airfoil/rib joint area are reduced while maintaining proper mechanical support of the nozzle side walls.

  20. Prototype Morphing Fan Nozzle Demonstrated

    NASA Technical Reports Server (NTRS)

    Lee, Ho-Jun; Song, Gang-Bing

    2004-01-01

    Ongoing research in NASA Glenn Research Center's Structural Mechanics and Dynamics Branch to develop smart materials technologies for aeropropulsion structural components has resulted in the design of the prototype morphing fan nozzle shown in the photograph. This prototype exploits the potential of smart materials to significantly improve the performance of existing aircraft engines by introducing new inherent capabilities for shape control, vibration damping, noise reduction, health monitoring, and flow manipulation. The novel design employs two different smart materials, a shape-memory alloy and magnetorheological fluids, to reduce the nozzle area by up to 30 percent. The prototype of the variable-area fan nozzle implements an overlapping spring leaf assembly to simplify the initial design and to provide ease of structural control. A single bundle of shape memory alloy wire actuators is used to reduce the nozzle geometry. The nozzle is subsequently held in the reduced-area configuration by using magnetorheological fluid brakes. This prototype uses the inherent advantages of shape memory alloys in providing large induced strains and of magnetorheological fluids in generating large resistive forces. In addition, the spring leaf design also functions as a return spring, once the magnetorheological fluid brakes are released, to help force the shape memory alloy wires to return to their original position. A computerized real-time control system uses the derivative-gain and proportional-gain algorithms to operate the system. This design represents a novel approach to the active control of high-bypass-ratio turbofan engines. Researchers have estimated that such engines will reduce thrust specific fuel consumption by 9 percent over that of fixed-geometry fan nozzles. This research was conducted under a cooperative agreement (NCC3-839) at the University of Akron.

  1. 75 FR 12535 - Midwest Independent Transmission System Operator, Inc., Complainant v. PJM Interconnection, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ... Interconnection, LLC Respondent; Notice of Complaint March 9, 2010. Take notice that on March 8, 2010, pursuant to... complaint against PJM Interconnection, LLC (Respondent) alleging that the Respondent is in violation of...

  2. 75 FR 12536 - Midwest Independent Transmission System Operator, Inc. Complainant v PJM Interconnection, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ... Interconnection, LLC Respondent; Notice of Complaint March 9, 2010. Take notice that on March 8, 2010, pursuant to... System Operator, Inc. (Complainant) filed a formal complaint against PJM Interconnection, LLC...

  3. Internal performance characteristics of vectored axisymmetric ejector nozzles

    NASA Technical Reports Server (NTRS)

    Lamb, Milton

    1993-01-01

    A series of vectoring axisymmetric ejector nozzles were designed and experimentally tested for internal performance and pumping characteristics at NASA-Langley Research Center. These ejector nozzles used convergent-divergent nozzles as the primary nozzles. The model geometric variables investigated were primary nozzle throat area, primary nozzle expansion ratio, effective ejector expansion ratio (ratio of shroud exit area to primary nozzle throat area), ratio of minimum ejector area to primary nozzle throat area, ratio of ejector upper slot height to lower slot height (measured on the vertical centerline), and thrust vector angle. The primary nozzle pressure ratio was varied from 2.0 to 10.0 depending upon primary nozzle throat area. The corrected ejector-to-primary nozzle weight-flow ratio was varied from 0 (no secondary flow) to approximately 0.21 (21 percent of primary weight-flow rate) depending on ejector nozzle configuration. In addition to the internal performance and pumping characteristics, static pressures were obtained on the shroud walls.

  4. Cold spray nozzle design

    DOEpatents

    Haynes, Jeffrey D.; Sanders, Stuart A.

    2009-06-09

    A nozzle for use in a cold spray technique is described. The nozzle has a passageway for spraying a powder material, the passageway having a converging section and a diverging section, and at least the diverging section being formed from polybenzimidazole. In one embodiment of the nozzle, the converging section is also formed from polybenzimidazole.

  5. Separate Flow Nozzle Test Status Meeting

    NASA Technical Reports Server (NTRS)

    Saiyed, Naseem H. (Editor)

    2000-01-01

    NASA Glenn, in partnership with US industry, completed an exhaustive experimental study on jet noise reduction from separate flow nozzle exhaust systems. The study developed a data base on various bypass ratio nozzles, screened quietest configurations and acquired pertinent data for predicting the plume behavior and ultimately its corresponding jet noise. Several exhaust system configurations provided over 2.5 EPNdB jet noise reduction at take-off power. These data were disseminated to US aerospace industry in a conference hosted by NASA GRC whose proceedings are shown in this report.

  6. Effect of Delta Tabs on Free Jets from Complex Nozzles

    NASA Technical Reports Server (NTRS)

    Zaman, K. B. M. Q.

    2001-01-01

    Effects of 'delta-tabs' on the mixing and noise characteristics of two model-scale nozzles have been investigated experimentally. The two models are (1) an eight-lobed nozzle simulating the primary flow of a mixer-ejector configuration considered for the HSCT program, (2) an axisymmetric nozzle with a centerbody simulating the 'ACE' configuration also considered for the HSCT program. Details of the flow-field for model (1) are explored, while primarily the noise-field is explored for model (2). Effects of different tab configurations are documented.

  7. Throat Flow Modelling of Expansion Deflection Nozzles

    NASA Astrophysics Data System (ADS)

    Taylor, N. V.; Hempsell, C. M.

    Modelling of the supersonic flow within a rocket nozzle of both conventional and expansion deflection (ED) design is well handled by Method of Characteristics based algorithms. This approach provides both a predic- tion of the flowfield, and allows efficient optimisation of nozzle shape with respect to length. However, the Method of Characteristics requires a solution of the transonic flow through the nozzle throat to provide initial conditions, and the accuracy of the description of the transonic flow will clearly affect the overall accuracy of the complete nozzle flow calculation. However, it is relatively simple to show that conventional analytical methods for this process break down when applied to the more complex throat geometry of ED nozzles. This requires the use of a time marching solution method, which allows the analysis of the flow within this region even on such advanced configurations. This paper demonstrates this capability, outlines a general method for ED nozzle throat geometric definition, and examines the effect of various throat parameters on the permissible range of ED contours. It is found that the design of length optimised ED nozzles is highly sensitive to small changes in these parameters, and hence they must be selected with care.

  8. Thrust improvement with ablative insert nozzle extension

    NASA Technical Reports Server (NTRS)

    Clayton, R. M.; Back, L. H.

    1986-01-01

    Aspects are examined of an investigation by the Marshall Space Flight Center into the conceptual feasibility of increasing the thrust performance of the Space Shuttle Main Engine (SSME) by using a conical nozzle extension fitted with an ablative insert in order to achieve a low-cost, near-term gain in payload. The ablating insert would provide a controlled increase in nozzle expansion ratio during launch and early climbout (first 30-60 seconds) so as to reduce thrust loss from nozzle over-expansion in the lower atmosphere. Summaries are given of JPL studies in the area of: defining the near-wall flow environment in the extended nozzle insert region; selecting potential insert materials; conceptualizing an extension/insert geometrical configuration; and identifying future experimental efforts necessary to verify the feasibility of the concepts.

  9. Nozzle and shroud assembly mounting structure

    DOEpatents

    Faulder, Leslie J.; Frey, deceased, Gary A.; Nielsen, Engward W.; Ridler, Kenneth J.

    1997-01-01

    The present nozzle and shroud assembly mounting structure configuration increases component life and reduces maintenance by reducing internal stress between the mounting structure having a preestablished rate of thermal expansion and the nozzle and shroud assembly having a preestablished rate of thermal expansion being less than that of the mounting structure. The mounting structure includes an outer sealing portion forming a cradling member in which an annular ring member is slidably positioned. The mounting structure further includes an inner mounting portion to which a hooked end of the nozzle and shroud assembly is attached. As the inner mounting portion expands and contracts, the nozzle and shroud assembly slidably moves within the outer sealing portion.

  10. Nozzle and shroud assembly mounting structure

    DOEpatents

    Faulder, L.J.; Frey, G.A.; Nielsen, E.W.; Ridler, K.J.

    1997-08-05

    The present nozzle and shroud assembly mounting structure configuration increases component life and reduces maintenance by reducing internal stress between the mounting structure having a preestablished rate of thermal expansion and the nozzle and shroud assembly having a preestablished rate of thermal expansion being less than that of the mounting structure. The mounting structure includes an outer sealing portion forming a cradling member in which an annular ring member is slidably positioned. The mounting structure further includes an inner mounting portion to which a hooked end of the nozzle and shroud assembly is attached. As the inner mounting portion expands and contracts, the nozzle and shroud assembly slidably moves within the outer sealing portion. 3 figs.

  11. Spiral cooled fuel nozzle

    DOEpatents

    Fox, Timothy; Schilp, Reinhard

    2012-09-25

    A fuel nozzle for delivery of fuel to a gas turbine engine. The fuel nozzle includes an outer nozzle wall and a center body located centrally within the nozzle wall. A gap is defined between an inner wall surface of the nozzle wall and an outer body surface of the center body for providing fuel flow in a longitudinal direction from an inlet end to an outlet end of the fuel nozzle. A turbulating feature is defined on at least one of the central body and the inner wall for causing at least a portion of the fuel flow in the gap to flow transverse to the longitudinal direction. The gap is effective to provide a substantially uniform temperature distribution along the nozzle wall in the circumferential direction.

  12. 75 FR 42390 - Orders Finding That the PJM WH Real Time Peak Contract and PJM WH Real Time Off-Peak Contract...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... thereunder. \\1\\ 74 FR 54966 (October 26, 2009). \\2\\ The acronym ``PJM'' stands for Pennsylvania New Jersey..., settlement or other daily price of another contract. \\7\\ 74 FR 12178 (Mar. 23, 2009); these rules became...., 2d Sess. 978, 986 (Conference Committee Report). See also 73 FR 75888, 75894 (Dec. 12, 2008). \\9\\...

  13. 75 FR 42399 - Orders Finding That the PJM WH Real Time Peak Daily Contract, PJM WH Real Time Off-Peak Daily...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-21

    ... Commission rule 36.3(c) promulgated thereunder. \\1\\ 74 FR 54966 (October 26, 2009). \\2\\ The acronym ``PJM... other daily price of another contract. \\7\\ 74 FR 12178 (Mar. 23, 2009); these rules became effective on... Committee Report). See also 73 FR 75888, 75894 (Dec. 12, 2008). \\9\\ For an initial SPDC, ECMs have a...

  14. Theoretical analysis on spray performance of centrifugal spray nozzle

    NASA Astrophysics Data System (ADS)

    Zhou, Meng; Zhuang, Fengchen

    1991-08-01

    The relationships between spray characteristics and the configurational parameters of a centrifugal spray nozzle are presently explored via the theory of momentum conservation. Predicted mean spray angles are substantially in accord with the experimental data obtained; the predicted nozzle discharge coefficients are slightly lower than experimental data, due to the ignoring of fluid viscosity effects.

  15. Commercial Building Loads Providing Ancillary Services in PJM

    SciTech Connect

    MacDonald, Jason; Kiliccote, Sila; Boch, Jim; Chen, Jonathan; Nawy, Robert

    2014-06-27

    The adoption of low carbon energy technologies such as variable renewable energy and electric vehicles, coupled with the efficacy of energy efficiency to reduce traditional base load has increased the uncertainty inherent in the net load shape. Handling this variability with slower, traditional resources leads to inefficient system dispatch, and in some cases may compromise reliability. Grid operators are looking to future energy technologies, such as automated demand response (DR), to provide capacity-based reliability services as the need for these services increase. While DR resources are expected to have the flexibility characteristics operators are looking for, demonstrations are necessary to build confidence in their capabilities. Additionally, building owners are uncertain of the monetary value and operational burden of providing these services. To address this, the present study demonstrates the ability of demand response resources providing two ancillary services in the PJM territory, synchronous reserve and regulation, using an OpenADR 2.0b signaling architecture. The loads under control include HVAC and lighting at a big box retail store and variable frequency fan loads. The study examines performance characteristics of the resource: the speed of response, communications latencies in the architecture, and accuracy of response. It also examines the frequency and duration of events and the value in the marketplace which can be used to examine if the opportunity is sufficient to entice building owners to participate.

  16. Liquid rocket engine nozzles

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The nozzle is a major component of a rocket engine, having a significant influence on the overall engine performance and representing a large fraction of the engine structure. The design of the nozzle consists of solving simultaneously two different problems: the definition of the shape of the wall that forms the expansion surface, and the delineation of the nozzle structure and hydraulic system. This monography addresses both of these problems. The shape of the wall is considered from immediately upstream of the throat to the nozzle exit for both bell and annular (or plug) nozzles. Important aspects of the methods used to generate nozzle wall shapes are covered for maximum-performance shapes and for nozzle contours based on criteria other than performance. The discussion of structure and hydraulics covers problem areas of regeneratively cooled tube-wall nozzles and extensions; it treats also nozzle extensions cooled by turbine exhaust gas, ablation-cooled extensions, and radiation-cooled extensions. The techniques that best enable the designer to develop the nozzle structure with as little difficulty as possible and at the lowest cost consistent with minimum weight and specified performance are described.

  17. Evaluation of nozzle shapes for an optical flow meter

    NASA Astrophysics Data System (ADS)

    Sheikholeslami, M. Z.; Patel, B. R.

    1992-05-01

    Numerical modeling is performed for turbulent flow in axisymmetric nozzles using Creare's computer program FLUENT/BFC. The primary objective of the project was to assist Spectron Development Laboratories in selecting an optimum nozzle shape for an optical flowmeter. The nozzle performance is evaluated for various length to diameter ratios, area contraction ratios, and Reynolds numbers. The computations have demonstrated that a cubic profile nozzle with length to diameter ratio of 1.6 and area contraction ratio of 6.2 can decrease the velocity profile non-uniformity from 15 percent at the entrance to 1 percent at the exit. The configuration is recommended for further investigation.

  18. High speed nozzles task

    NASA Technical Reports Server (NTRS)

    Hamed, Awatef

    1995-01-01

    Supersonic cruise exhaust nozzles for advanced applications are optimized for a high nozzle pressure ratio (NPR) at design supersonic cruise Mach number and altitude. The performance of these nozzles with large expansion ratios are severely degraded for operations at subsonic speeds near sea level for NPR significantly less than the design values. The prediction of over-expanded 2DCD nozzles performance is critical to evaluating the internal losses and to the optimization of the integrated vehicle and propulsion system performance. The reported research work was aimed at validating and assessing existing computational methods and turbulence models for predicting the flow characteristics and nozzle performance at over-expanded conditions. Flow simulations in 2DCD nozzles were performed using five different turbulence models. The results are compared with the experimental data for the wall pressure distribution and thrust and flow coefficients at over-expanded static conditions.

  19. Turbine nozzle positioning system

    DOEpatents

    Norton, Paul F.; Shaffer, James E.

    1996-01-30

    A nozzle guide vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The nozzle guide vane assembly includes an outer shroud having a mounting leg with an opening defined therein, a tip shoe ring having a mounting member with an opening defined therein, a nozzle support ring having a plurality of holes therein and a pin positioned in the corresponding opening in the outer shroud, opening in the tip shoe ring and the hole in the nozzle support ring. A rolling joint is provided between metallic components of the gas turbine engine and the nozzle guide vane assembly. The nozzle guide vane assembly is positioned radially about a central axis of the gas turbine engine and axially aligned with a combustor of the gas turbine engine.

  20. Turbine nozzle positioning system

    DOEpatents

    Norton, P.F.; Shaffer, J.E.

    1996-01-30

    A nozzle guide vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The nozzle guide vane assembly includes an outer shroud having a mounting leg with an opening defined therein, a tip shoe ring having a mounting member with an opening defined therein, a nozzle support ring having a plurality of holes therein and a pin positioned in the corresponding opening in the outer shroud, opening in the tip shoe ring and the hole in the nozzle support ring. A rolling joint is provided between metallic components of the gas turbine engine and the nozzle guide vane assembly. The nozzle guide vane assembly is positioned radially about a central axis of the gas turbine engine and axially aligned with a combustor of the gas turbine engine. 9 figs.

  1. 75 FR 12230 - Black Oak Energy, L.L.C., EPIC Merchant Energy, LP, SESCO Enterprises, LLC v. PJM Interconnection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-15

    ... Energy Regulatory Commission Black Oak Energy, L.L.C., EPIC Merchant Energy, LP, SESCO Enterprises, LLC v. PJM Interconnection, L.L.C.; Notice of Filing March 8, 2010. Take notice that on March 1, 2010, PJM Interconnection, L.L.C. filed a report of refund pursuant to the Federal Energy Regulatory...

  2. 77 FR 65544 - Dominion Resources Services, Inc. v. PJM Interconnection, L.L.C.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Dominion Resources Services, Inc. v. PJM Interconnection, L.L.C.; Notice of.... (Complainant) filed a formal complaint against PJM Interconnection, L.L.C. (Respondent), alleging that...

  3. Scale model test results of several STOVL ventral nozzle concepts

    NASA Technical Reports Server (NTRS)

    Meyer, B. E.; Re, R. J.; Yetter, J. A.

    1991-01-01

    Short take-off and vertical landing (STOVL) ventral nozzle concepts are investigated by means of a static cold flow scale model at a NASA facility. The internal aerodynamic performance characteristics of the cruise, transition, and vertical lift modes are considered for four ventral nozzle types. The nozzle configurations examined include those with: butterfly-type inner doors and vectoring exit vanes; circumferential inner doors and thrust vectoring vanes; a three-port segmented version with circumferential inner doors; and a two-port segmented version with cylindrical nozzle exit shells. During the testing, internal and external pressure is measured, and the thrust and flow coefficients and resultant vector angles are obtained. The inner door used for ventral nozzle flow control is found to affect performance negatively during the initial phase of transition. The best thrust performance is demonstrated by the two-port segmented ventral nozzle due to the elimination of the inner door.

  4. Advanced subsonic Technology Noise Reduction Element Separate Flow Nozzle Tests for Engine Noise Reduction Sub-Element

    NASA Technical Reports Server (NTRS)

    Saiyed, Naseem H.

    2000-01-01

    Contents of this presentation include: Advanced Subsonic Technology (AST) goals and general information; Nozzle nomenclature; Nozzle schematics; Photograph of all baselines; Configurations tests and types of data acquired; and Engine cycle and plug geometry impact on EPNL.

  5. Numerical Modeling of a Magnetic Nozzle

    NASA Astrophysics Data System (ADS)

    Tushentsov, Mikhail; Breizman, Boris; Arefiev, Alexey

    2007-11-01

    We present computational study of a magnetic nozzle, which is a component of the VASIMR (Variable Specific Impulse Magnetoplasma Rocket) plasma-based propulsion system for a space vehicle. The magnetic nozzle transforms ion gyromotion into directed axial motion, adiabatically accelerating the plasma, and enabling plasma detachment from the spaceship via self-consistent magnetic field modification. VASIMR employs ion cyclotron resonance heating to deposit rf-power directly to the plasma ions created by the low energy plasma source. We have developed a numerical code to model the axisymmetric nozzle within the framework of collisionless MHD with an azimuthal ion velocity spread. The code implements a reduced model that consists of truncated steady-state equations for the velocity space moments of the ion distribution function and takes advantage of the plasma flow paraxiality. This makes it possible to study the conversion of the ion gyro-energy at the nozzle entrance into the energy of the directed flow at the exhaust. The magnetic field in the vacuum, which is not assumed to be paraxial, is calculated using a given magnetic coil configuration in the presence of plasma. From the computed steady-state flow configuration, the code evaluates magnetic nozzle efficiency, defined as the ratio of the axial momentum flux in the outgoing flow to the axial momentum flux in the incoming flow.

  6. Assessment at full scale of exhaust nozzle to wing size on STOL-OTW acoustic characteristics

    NASA Technical Reports Server (NTRS)

    Vonglahn, U.; Grosbeck, D.

    1979-01-01

    On the basis of static aero/acoustic data obtained at model scale, the effect of exhaust nozzle size on flyover noise is evaluated at full scale for different STOL-OTW nozzle configurations. Three types of nozzles are evaluated: a circular/deflector nozzle mounted above the wing; a slot/deflector nozzle mounted on the wing; and a slot nozzle mounted on the wing. The nozzle exhaust plane location, measured from the wing leading edge, was varied from 10 to 46 percent of the wing chord (flaps retracted). Flap angles of 20 deg (takeoff) and 60 deg (approach) are included in the study. Initially, perceived noise levels (PNL) are calculated as a function flyover distance at 152m altitude. From these plots, static EPNL values (defined as flyover relative noise levels), are obtained as functions of nozzle size for equal aerodynamic performance (lift and thrust). The acoustic benefits attributable to nozzle size relative to a given wing chord size are assessed.

  7. Flux Compression Magnetic Nozzle

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

    2001-01-01

    In pulsed fusion propulsion schemes in which the fusion energy creates a radially expanding plasma, a magnetic nozzle is required to redirect the radially diverging flow of the expanding fusion plasma into a rearward axial flow, thereby producing a forward axial impulse to the vehicle. In a highly electrically conducting plasma, the presence of a magnetic field B in the plasma creates a pressure B(exp 2)/2(mu) in the plasma, the magnetic pressure. A gradient in the magnetic pressure can be used to decelerate the plasma traveling in the direction of increasing magnetic field, or to accelerate a plasma from rest in the direction of decreasing magnetic pressure. In principle, ignoring dissipative processes, it is possible to design magnetic configurations to produce an 'elastic' deflection of a plasma beam. In particular, it is conceivable that, by an appropriate arrangement of a set of coils, a good approximation to a parabolic 'magnetic mirror' may be formed, such that a beam of charged particles emanating from the focal point of the parabolic mirror would be reflected by the mirror to travel axially away from the mirror. The degree to which this may be accomplished depends on the degree of control one has over the flux surface of the magnetic field, which changes as a result of its interaction with a moving plasma.

  8. Biannular Airbreathing Nozzle Rig (BANR) facility checkout and plug nozzle performance test data

    NASA Astrophysics Data System (ADS)

    Cummings, Chase B.

    2010-09-01

    The motivation for development of a supersonic business jet (SSBJ) platform lies in its ability to create a paradigm shift in the speed and reach of commercial, private, and government travel. A full understanding of the performance capabilities of exhaust nozzle configurations intended for use in potential SSBJ propulsion systems is critical to the design of an aircraft of this type. Purdue University's newly operational Biannular Airbreathing Nozzle Rig (BANR) is a highly capable facility devoted to the testing of subscale nozzles of this type. The high accuracy, six-axis force measurement system and complementary mass flowrate measurement capabilities of the BANR facility make it rather ideally suited for exhaust nozzle performance appraisal. Detailed accounts pertaining to methods utilized in the proper checkout of these diagnostic capabilities are contained herein. Efforts to quantify uncertainties associated with critical BANR test measurements are recounted, as well. Results of a second hot-fire test campaign of a subscale Gulfstream Aerospace Corporation (GAC) axisymmetric, shrouded plug nozzle are presented. Determined test article performance parameters (nozzle thrust efficiencies and discharge coefficients) are compared to those of a previous test campaign and numerical simulations of the experimental set-up. Recently acquired data is compared to published findings pertaining to plug nozzle experiments of similar scale and operating range. Suggestions relating to the future advancement and improvement of the BANR facility are provided. Lessons learned with regards to test operations and calibration procedures are divulged in an attempt to aid future facility users, as well.

  9. Stress and Fracture Mechanics Analyses of Boiling Water Reactor and Pressurized Water Reactor Pressure Vessel Nozzles

    SciTech Connect

    Yin, Shengjun; Bass, Bennett Richard; Stevens, Gary; Kirk, Mark

    2011-01-01

    This paper describes stress analysis and fracture mechanics work performed to assess boiling water reactor (BWR) and pressurized water reactor (PWR) nozzles located in the reactor pressure vessel (RPV) adjacent to the core beltline region. Various RPV nozzle geometries were investigated: 1. BWR recirculation outlet nozzle; 2. BWR core spray nozzle3 3. PWR inlet nozzle; ; 4. PWR outlet nozzle; and 5. BWR partial penetration instrument nozzle. The above nozzle designs were selected based on their proximity to the core beltline region, i.e., those nozzle configurations that are located close enough to the core region such that they may receive sufficient fluence prior to end-of-license (EOL) to require evaluation as part of establishing the allowed limits on heatup, cooldown, and hydrotest (leak test) conditions. These nozzles analyzed represent one each of the nozzle types potentially requiring evaluation. The purpose of the analyses performed on these nozzle designs was as follows: To model and understand differences in pressure and thermal stress results using a two-dimensional (2-D) axi-symmetric finite element model (FEM) versus a three-dimensional (3-D) FEM for all nozzle types. In particular, the ovalization (stress concentration) effect of two intersecting cylinders, which is typical of RPV nozzle configurations, was investigated; To verify the accuracy of a selected linear elastic fracture mechanics (LEFM) hand solution for stress intensity factor for a postulated nozzle corner crack for both thermal and pressure loading for all nozzle types; To assess the significance of attached piping loads on the stresses in the nozzle corner region; and To assess the significance of applying pressure on the crack face with respect to the stress intensity factor for a postulated nozzle corner crack.

  10. Tests and analysis of a vented D thrust deflecting nozzle on a turbofan engine. [conducted at the outdoor aerodynamic research facility of the Ames Research Center

    NASA Technical Reports Server (NTRS)

    Roseberg, E. W.

    1982-01-01

    The objectives were to: obtain nozzle performance characteristics in and out of ground effects; demonstrate the compatibility of the nozzle with a turbofan engine; obtain pressure and temperature distributions on the surface of the D vented nozzle; and establish a correlation of the nozzle performance between small scale and large scale models. The test nozzle was a boilerplate model of the MCAIR D vented nozzle configured for operation with a General Electric YTF-34-F5 turbofan engine. The nozzle was configured to provide: a thrust vectoring range of 0 to 115 deg; a yaw vectoring range of 0 to 10 deg; variable nozzle area control; and variable spacing between the core exit and nozzle entrance station. Compatibility between the YTF-34-T5 turbofan engine and the D vented nozzle was demonstrated. Velocity coefficients of 0.96 and greater were obtained for 90 deg of thrust vectoring. The nozzle walls remained cool during all test conditions.

  11. Gas only nozzle fuel tip

    DOEpatents

    Bechtel, William Theodore; Fitts, David Orus; DeLeonardo, Guy Wayne

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozzle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  12. Wing aerodynamic loading caused by jet-induced lift associated with STOL-OTW configurations

    NASA Technical Reports Server (NTRS)

    Vonglahn, U.; Groesbeck, D.

    1979-01-01

    Surface pressure distributions were obtained with model-scale STOL-OTW configurations using various nozzles designed to promote flow attachment to the wing/flap surface. The nozzle configurations included slot-types and both circular and slot nozzles with external flow deflectors. The wing aerodynamic loading caused by the jet-induced lift is presented in conventional terms of delta p/q as a function of chordwise surface distance in the nozzle centerline plane as well as outboard of the nozzle centerline. Nozzle roof/deflector angle, chordwise location of the nozzle, wing size, and flap deflection angle are included in the geometric variables affecting the wing loading.

  13. Wing aerodynamic loading caused by jet-induced lift associated with STOL-OTW configurations

    NASA Technical Reports Server (NTRS)

    Von Glahn, U.; Groesbeck, D.

    1979-01-01

    Surface pressure distributions were obtained with model-scale STOL-OTW configurations using various nozzles designed to promote flow attachment to the wing-flap surface. The nozzle configurations included slot-types and both circular and slot nozzles with external flow deflectors. The wing aerodynamic loading caused by the jet-induced lift is presented in conventional terms of delta p/q as a function of chordwise surface distance in the nozzle centerline plane as well as outboard of the nozzle centerline. Included in the geometric variables affecting the wing loading are nozzle roof/deflector angle, chordwise location of the nozzle, wing size, and flap deflection angle.

  14. 76 FR 29744 - Monongahela Power Company, West Penn Power Company, The Potomac Edison Company, PJM...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-23

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Monongahela Power Company, West Penn Power Company, The Potomac... FirstEnergy Utilities), and PJM Interconnection, L.L.C. filed a joint petition requesting that...

  15. Consequential life cycle air emissions externalities for plug-in electric vehicles in the PJM interconnection

    NASA Astrophysics Data System (ADS)

    Weis, Allison; Jaramillo, Paulina; Michalek, Jeremy

    2016-02-01

    We perform a consequential life cycle analysis of plug-in electric vehicles (PEVs), hybrid electric vehicles (HEVs), and conventional gasoline vehicles in the PJM interconnection using a detailed, normative optimization model of the PJM electricity grid that captures the change in power plant operations and related emissions due to vehicle charging. We estimate and monetize the resulting human health and environmental damages from life cycle air emissions for each vehicle technology. We model PJM using the most recent data available (2010) as well as projections of the PJM grid in 2018 and a hypothetical scenario with increased wind penetration. We assess a range of sensitivity cases to verify the robustness of our results. We find that PEVs have higher life cycle air emissions damages than gasoline HEVs in the recent grid scenario, which has a high percentage of coal generation on the margin. In particular, battery electric vehicles with large battery capacity can produce two to three times as much air emissions damage as gasoline HEVs, depending on charge timing. In our future 2018 grid scenarios that account for predicted coal plant retirements, PEVs would produce air emissions damages comparable to or slightly lower than HEVs.

  16. The impact of FERC orders on the value of bidders in PJM

    SciTech Connect

    Peters, Lon L.

    2009-08-15

    A study of the responses of share prices of major bidders in the PJM auctions from the mid-1990s through 2006 finds statistically significant effects for some FERC decisions for a portfolio of bidders. In contrast to publicly stated policy objectives, the analysis shows that some FERC decisions significantly raised market expectations regarding the future profitability of bidders. (author)

  17. 77 FR 6557 - PJM Interconnection, L.L.C.; Supplemental Notice for Staff Technical Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Interconnection, L.L.C.; Supplemental Notice for Staff Technical Conference Take notice that the staff technical conference in the above captioned proceeding, to be held...

  18. 78 FR 66915 - Supplemental Notice for Staff Technical Conference; PJM Interconnection, L.L.C.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Supplemental Notice for Staff Technical Conference; PJM Interconnection, L.L.C. As announced in the Notice of Technical Conference issued on October 11, 2013, there will be...

  19. 77 FR 21094 - Viridity Energy, Inc. v. PJM Interconnection, L.L.C.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Viridity Energy, Inc. v. PJM Interconnection, L.L.C.; Notice of Complaint... Interconnection, L.L.C. (Respondent) alleging that a portion of a provision in the Respondent's Open...

  20. 76 FR 48841 - PJM Interconnection, L.L.C.; Notice Establishing Post-Technical Comment Period

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-09

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Interconnection, L.L.C.; Notice Establishing Post-Technical Comment Period As indicated in the June 21, 2011 Notice in this docket, comments on the technical conference...

  1. Controlled overspray spray nozzle

    NASA Technical Reports Server (NTRS)

    Prasthofer, W. P. (Inventor)

    1981-01-01

    A spray system for a multi-ingredient ablative material wherein a nozzle A is utilized for suppressing overspray is described. The nozzle includes a cyclindrical inlet which converges to a restricted throat. A curved juncture between the cylindrical inlet and the convergent portion affords unrestricted and uninterrupted flow of the ablative material. A divergent bell-shaped chamber and adjustable nozzle exit B is utilized which provides a highly effective spray pattern in suppressing overspray to an acceptable level and producing a homogeneous jet of material that adheres well to the substrate.

  2. Nozzle for a turbomachine

    DOEpatents

    Lacy, Benjamin Paul; Kraemer, Gilbert Otto; Yilmaz, Ertan; Melton, Patrick Benedict

    2012-10-30

    A turbomachine includes a compressor, a combustor operatively connected to the compressor, and an injection nozzle operatively connected to the combustor. The injection nozzle includes a main body having a first end section that extends to a second end section to define an inner flow path. The injection nozzle further includes an outlet arranged at the second end section of the main body, at least one passage that extends within the main body and is fluidly connected to the outlet, and at least one conduit extending between the inner flow path and the at least one passage.

  3. SCOUT Nozzle Data Book

    NASA Technical Reports Server (NTRS)

    Shieds, S.

    1976-01-01

    Available analyses and material property information are summarized relevant to the design of four rocket motor nozzles currently incorporated in the four solid propellant rocket stages of the NASA SCOUT launch vehicle. The nozzles discussed include those for the following motors: (1) first stage - Algol IIIA; (2) second stage - Castor IIA; (3) third stage - Antares IIA; and (4) fourth stage - Altair IIIA. Separate sections for each nozzle provide complete data packages. Information on the Antares IIB motor which had limited usage as an alternate motor for the third stage is included.

  4. Wear characterization of abrasive waterjet nozzles and nozzle materials

    NASA Astrophysics Data System (ADS)

    Nanduri, Madhusarathi

    Parameters that influence nozzle wear in the abrasive water jet (AWJ) environment were identified and classified into nozzle geometric, AWJ system, and nozzle material categories. Regular and accelerated wear test procedures were developed to study nozzle wear under actual and simulated conditions, respectively. Long term tests, using garnet abrasive, were conducted to validate the accelerated test procedure. In addition to exit diameter growth, two new measures of wear, nozzle weight loss and nozzle bore profiles were shown to be invaluable in characterizing and explaining the phenomena of nozzle wear. By conducting nozzle wear tests, the effects of nozzle geometric, and AWJ system parameters on nozzle wear were systematically investigated. An empirical model was developed for nozzle weight loss rate. To understand the response of nozzle materials under varying AWJ system conditions, erosion tests were conducted on samples of typical nozzle materials. The effect of factors such as jet impingement angle, abrasive type, abrasive size, abrasive flow rate, water pressure, traverse speed, and target material was evaluated. Scanning electron microscopy was performed on eroded samples as well as worn nozzles to understand the wear mechanisms. The dominant wear mechanism observed was grain pullout. Erosion models were reviewed and along the lines of classical erosion theories a semi-empirical model, suitable for erosion of nozzle materials under AWJ impact, was developed. The erosion data correlated very well with the developed model. Finally, the cutting efficiency of AWJ nozzles was investigated in conjunction with nozzle wear. The cutting efficiency of a nozzle deteriorates as it wears. There is a direct correlation between nozzle wear and cutting efficiency. The operating conditions that produce the most efficient jets also cause the most wear in the nozzle.

  5. MEMS-Based Spinning Nozzle

    NASA Technical Reports Server (NTRS)

    Okojie, Robert S. (Inventor)

    2003-01-01

    A nozzle body and assembly for delivering atomized fuel to a combustion chamber. The nozzle body is rotatably mounted onto a substrate. One or more curvilinear fuel delivery channels are in flow communication with an internal fuel distribution cavity formed in the nozzle body. Passage of pressurized fuel through the nozzle body causes the nozzle body to rotate. Components of the nozzle assembly are formed of silicon carbide having surfaces etched by deep reactive ion etching utilizing MEMS (micro-electro-mechanical systems) technology. A fuel premix chamber is carried on the substrate in flow communication with a supply passage in the nozzle body.

  6. Laser cutting nozzle

    DOEpatents

    Ramos, Terry J.

    1984-01-01

    A laser cutting nozzle for use with a laser cutting apparatus directing a focused beam to a spot on a work piece. The nozzle has a cylindrical body with a conical tip which together have a conically shaped hollow interior with the apex at a small aperture through the tip. The conical hollow interior is shaped to match the profile of the laser beam, at full beamwidth, which passes through the nozzle to the work piece. A plurality of gas inlet holes extend through the body to the hollow interior and are oriented to produce a swirling flow of gas coaxially through the nozzle and out the aperture, aligned with the laser beam, to the work piece. BACKGROUND OF THE INVENTION

  7. Ceramic turbine nozzle

    DOEpatents

    Shaffer, J.E.; Norton, P.F.

    1996-12-17

    A turbine nozzle and shroud assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The metallic components have a preestablished rate of thermal expansion greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes a plurality of segmented vane defining a first vane segment and a second vane segment, each of the first and second vane segments having a vertical portion, and each of the first vane segments and the second vane segments being positioned in functional relationship one to another within a recess formed within an outer shroud and an inner shroud. The turbine nozzle and shroud assembly provides an economical, reliable and effective ceramic component having a preestablished rate of thermal expansion being less than the preestablished rate of thermal expansion of the other component. 4 figs.

  8. Ceramic turbine nozzle

    DOEpatents

    Shaffer, James E.; Norton, Paul F.

    1996-01-01

    A turbine nozzle and shroud assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The metallic components having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes a plurality of segmented vane defining a first vane segment and a second vane segment. Each of the first and second vane segments having a vertical portion. Each of the first vane segments and the second vane segments being positioned in functional relationship one to another within a recess formed within an outer shroud and an inner shroud. The turbine nozzle and shroud assembly provides an economical, reliable and effective ceramic component having a preestablished rate of thermal expansion being less than the preestablished rate of thermal expansion of the other component.

  9. Laser cutting nozzle

    DOEpatents

    Ramos, T.J.

    1982-09-30

    A laser cutting nozzle for use with a laser cutting apparatus directing a focused beam to a spot on a work piece. The nozzle has a cylindrical body with a conical tip which together have a conically shaped hollow interior with the apex at a small aperture through the tip. The conical hollow interior is shaped to match the profile of the laser beam, at full beamwidth, which passes through the nozzle to the work piece. A plurality of gas inlet holes extend through the body to the hollow interior and are oriented to produce a swirling flow of gas coaxially through the nozzle and out the aperture, aligned with the laser beam, to the work piece.

  10. Ceramic Cerami Turbine Nozzle

    DOEpatents

    Boyd, Gary L.

    1997-04-01

    A turbine nozzle vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The metallic components having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes an outer shroud and an inner shroud having a plurality of horizontally segmented vanes therebetween being positioned by a connecting member positioning segmented vanes in functional relationship one to another. The turbine nozzle vane assembly provides an economical, reliable and effective ceramic component having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the other component.

  11. Transonic wind tunnel test of a supersonic nozzle installation

    NASA Technical Reports Server (NTRS)

    Yetter, J. A.; Evelyn, G. B.; Mercer, C.

    1982-01-01

    The design of the propulsion system installation affects strongly the total drag and overall performance of an aircraft, and the concept, placement, and integration details of the exhaust nozzle are major considerations in the configuration definition. As part of the NASA Supersonic Cruise Research (SCR) program, a wind tunnel test program has been conducted to investigate exhaust nozzle-airframe interactions at transonic speeds. First phase testing is to establish guidelines for follow-on testing. A summary is provided of the results of first phase testing, taking into account the test approach, the effect of nozzle closure on aircraft aerodynamic characteristics, nozzle installation effects and nacelle interference drag, and an analytical study of the effects of nozzle closure on the aircraft.

  12. Atomizing nozzle and process

    DOEpatents

    Anderson, Iver E.; Figliola, Richard S.; Molnar, Holly M.

    1992-06-30

    High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

  13. REACTOR NOZZLE ASSEMBLY

    DOEpatents

    Capuder, F.C.; Dearwater, J.R.

    1959-02-10

    An improved nozzle assembly useful in a process for the direct reduction of uranium hexafluoride to uranium tetrafluoride by means of dissociated ammonia in a heated reaction vessel is descrlbed. The nozzle design provides for intimate mixing of the two reactants and at the same time furnishes a layer of dissociated ammonia adjacent to the interior wall of the reaction vessel, thus preventing build-up of the reaction product on the vessel wall.

  14. Metal atomization spray nozzle

    DOEpatents

    Huxford, T.J.

    1993-11-16

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

  15. Metal atomization spray nozzle

    DOEpatents

    Huxford, Theodore J.

    1993-01-01

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal.

  16. Atomizing nozzle and process

    DOEpatents

    Anderson, I.E.; Figliola, R.S.; Molnar, H.M.

    1993-07-20

    High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

  17. 77 FR 790 - FirstEnergy Solutions Corp., Allegheny Energy Supply Company, LLC v. PJM Interconnection, L.L.C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... Interconnection, L.L.C.; Notice of Complaint Take notice that on December 28, 2011, pursuant to section 206 and... Company, LLC (Complainants), collectively filed a formal complaint against PJM Interconnection,...

  18. 78 FR 12750 - FirstEnergy Solutions Corp., Allegheny Energy Supply Company, LLC v. PJM Interconnection, L.L.C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... Interconnection, L.L.C.; Notice of Complaint Take notice that on February 15, 2013, pursuant to section 206 of the... Allegheny Energy Supply Company, LLC (Complainants) filed a formal complaint against PJM Interconnection,...

  19. Factors which influence the analysis and design of ejector nozzles

    NASA Technical Reports Server (NTRS)

    Anderson, B. H.

    1972-01-01

    A theoretical analysis of the viscous interaction between the primary and secondary streams of ejector nozzles was developed. The analysis accounts for real sonic line effects and the streamwise variation in stream mixing and boundary layer within the ejector. The aspects of the analysis are explained and illustrated by applying the theory to a variety of ejector configurations including cylindrical shroud, contoured flap and plug nozzles. Extensive comparisons are made between theory and data to show the importance of various analytical assumptions and such design variables as diameter ratio, spacing ratio, total temperature ratio, and primary nozzle geometry.

  20. Multi-tube fuel nozzle with mixing features

    SciTech Connect

    Hughes, Michael John

    2014-04-22

    A system includes a multi-tube fuel nozzle having an inlet plate and a plurality of tubes adjacent the inlet plate. The inlet plate includes a plurality of apertures, and each aperture includes an inlet feature. Each tube of the plurality of tubes is coupled to an aperture of the plurality of apertures. The multi-tube fuel nozzle includes a differential configuration of inlet features among the plurality of tubes.

  1. Analytical study of nozzle performance for nuclear thermal rockets

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth O.; Kacynski, Kenneth J.

    1991-01-01

    Nuclear propulsion has been identified as one of the key technologies needed for human exploration of the Moon and Mars. The Nuclear Thermal Rocket (NTR) uses a nuclear reactor to heat hydrogen to a high temperature followed by expansion through a conventional convergent-divergent nozzle. A parametric study of NTR nozzles was performed using the Rocket Engine Design Expert System (REDES) at the NASA Lewis Research Center. The REDES used the JANNAF standard rigorous methodology to determine nozzle performance over a range of chamber temperatures, chamber pressures, thrust levels, and different nozzle configurations. A design condition was set by fixing the propulsion system exit radius at five meters and throat radius was varied to achieve a target thrust level. An adiabatic wall was assumed for the nozzle, and its length was assumed to be 80 percent of a 15 degree cone. The results conclude that although the performance of the NTR, based on infinite reaction rates, looks promising at low chamber pressures, finite rate chemical reactions will cause the actual performance to be considerably lower. Parameters which have a major influence on the delivered specific impulse value include the chamber temperature and the chamber pressures in the high thrust domain. Other parameters, such as 2-D and boundary layer effects, kinetic rates, and number of nozzles, affect the deliverable performance of an NTR nozzle to a lesser degree. For a single nozzle, maximum performance of 930 seconds and 1030 seconds occur at chamber temperatures of 2700 and 3100 K, respectively.

  2. Effects of varying podded nacelle-nozzle installations on transonic aeropropulsive characteristics of a supersonic fighter aircraft

    NASA Technical Reports Server (NTRS)

    Capone, F. J.; Reubush, D. E.

    1983-01-01

    The aeropropulsive characteristics of an advanced twin engine fighter designed for supersonic cruise was investigated in the 16 foot Transonic Tunnel. The performance characteristics of advanced nonaxisymmetric nozzles installed in various nacelle locations, the effects of thrust induced forces on overall aircraft aerodynamics, the trim characteristics, and the thrust reverser performance were evaluated. The major model variables included nozzle power setting; nozzle duct aspect ratio; forward, mid, and aft nacelle axial locations; inboard and outboard underwing nacelle locations; and underwing and overwing nacelle locations. Thrust vectoring exhaust nozzle configurations included a wedge nozzle, a two dimensional convergent divergent nozzle, and a single expansion ramp nozzle, each with deflection angles up to 30 deg. In addition to the nonaxisymmetric nozzles, an axisymmetric nozzle installation was also tested. The use of a canard for trim was also assessed.

  3. Measuring market performance in restructured electricity markets: An empirical analysis of the PJM energy market

    NASA Astrophysics Data System (ADS)

    Tucker, Russell Jay

    2002-09-01

    Today the electric industry in the U.S. is transitioning to competitive markets for wholesale electricity. Independent system operators (ISOs) now manage broad regional markets for electrical energy in several areas of the U.S. A recent rulemaking by the Federal Energy Regulatory Commission (FERC) encourages the development of regional transmission organizations (RTOs) and restructured competitive wholesale electricity markets nationwide. To date, the transition to competitive wholesale markets has not been easy. The increased reliance on market forces coupled with unusually high electricity demand for some periods have created conditions amenable to market power abuse in many regions throughout the U.S. In the summer of 1999, hot and humid summer conditions in Pennsylvania, New Jersey, Maryland, Delaware, and the District of Columbia pushed peak demand in the PJM Interconnection to record levels. These demand conditions coincided with the introduction of market-based pricing in the wholesale electricity market. Prices for electricity increased on average by 55 percent, and reached the $1,000/MWh range. This study examines the extent to which generator market power raised prices above competitive levels in the PJM Interconnection during the summer of 1999. It simulates hourly market-clearing prices assuming competitive market behavior and compares these prices with observed market prices in computing price markups over the April 1-August 31, 1999 period. The results of the simulation analysis are supported with an examination of actual generator bid data of incumbent generators. Price markups averaged 14.7 percent above expected marginal cost over the 5-month period for all non-transmission-constrained hours. The evidence presented suggests that the June and July monthly markups were strongly influenced by generator market power as price inelastic peak demand approached the electricity generation capacity constraint of the market. While this analysis of the

  4. Turbine nozzle attachment system

    DOEpatents

    Norton, P.F.; Shaffer, J.E.

    1995-10-24

    A nozzle guide vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and is attached to conventional metallic components. The nozzle guide vane assembly includes a pair of legs extending radially outwardly from an outer shroud and a pair of mounting legs extending radially inwardly from an inner shroud. Each of the pair of legs and mounting legs have a pair of holes therein. A plurality of members attached to the gas turbine engine have a plurality of bores therein which axially align with corresponding ones of the pair of holes in the legs. A plurality of pins are positioned within the corresponding holes and bores radially positioning the nozzle guide vane assembly about a central axis of the gas turbine engine. 3 figs.

  5. Turbine nozzle attachment system

    DOEpatents

    Norton, Paul F.; Shaffer, James E.

    1995-01-01

    A nozzle guide vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The nozzle guide vane assembly includes a pair of legs extending radially outwardly from an outer shroud and a pair of mounting legs extending radially inwardly from an inner shroud. Each of the pair of legs and mounting legs have a pair of holes therein. A plurality of members attached to the gas turbine engine have a plurality of bores therein which axially align with corresponding ones of the pair of holes in the legs. A plurality of pins are positioned within the corresponding holes and bores radially positioning the nozzle guide vane assembly about a central axis of the gas turbine engine.

  6. Oil burner nozzle

    DOEpatents

    Wright, Donald G.

    1982-01-01

    An oil burner nozzle for use with liquid fuels and solid-containing liquid fuels. The nozzle comprises a fuel-carrying pipe, a barrel concentrically disposed about the pipe, and an outer sleeve retaining member for the barrel. An atomizing vapor passes along an axial passageway in the barrel, through a bore in the barrel and then along the outer surface of the front portion of the barrel. The atomizing vapor is directed by the outer sleeve across the path of the fuel as it emerges from the barrel. The fuel is atomized and may then be ignited.

  7. Experimental results for a two-dimensional supersonic inlet used as a thrust deflecting nozzle

    NASA Technical Reports Server (NTRS)

    Johns, Albert L.; Burstadt, Paul L.

    1984-01-01

    Nearly all supersonic V/STOL aircraft concepts are dependent on the thrust deflecting capability of a nozzle. In one unique concept, referred to as the reverse flow dual fan, not only is there a thrust deflecting nozzle for the fan and core engine exit flow, but because of the way the propulsion system operates during vertical takeoff and landing, the supersonic inlet is also used as a thrust deflecting nozzle. This paper presents results of an experimental study to evaluate the performance of a supersonic inlet used as a thrust deflecting nozzle for this reverse flow dual fan concept. Results are presented in terms of nozzle thrust coefficient and thrust vector angle for a number of inlet/nozzle configurations. Flow visualization and nozzle exit flow survey results are also shown.

  8. Particle impingement in SRM nozzles

    NASA Astrophysics Data System (ADS)

    Ikeda, Hirohide; Tanno, Haruhito; Tokudome, Shinichiro; Kohno, Masahiro

    It is experimentally shown that an improved two-phase flow program can well predict the alumina particle impingement location in small rocket motor nozzles as well as motor performance. The size distribution of particles in the nozzle flow is well characterized by a log-normal distribution. The program has achieved sufficient accuracy of prediction to be an effective nozzle contouring design tool.

  9. Duplex tab exhaust nozzle

    NASA Technical Reports Server (NTRS)

    Gutmark, Ephraim Jeff (Inventor); Martens, Steven (nmn) (Inventor)

    2012-01-01

    An exhaust nozzle includes a conical duct terminating in an annular outlet. A row of vortex generating duplex tabs are mounted in the outlet. The tabs have compound radial and circumferential aft inclination inside the outlet for generating streamwise vortices for attenuating exhaust noise while reducing performance loss.

  10. Welding nozzle position manipulator

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L. (Inventor); Gutow, David A. (Inventor)

    1994-01-01

    The present invention is directed to a welding nozzle position manipulator. The manipulator consists of an angle support to which the remaining components of the device are attached either directly or indirectly. A pair of pivotal connections attach a weld nozzle holding link to the angle support and provide a two axis freedom of movement of the holding link with respect to the support angle. The manipulator is actuated by a pair of adjusting screws angularly mounted to the angle support. These screws contact a pair of tapered friction surfaces formed on the upper portion of the welding nozzle holding link. A spring positioned between the upper portions of the support angle and the holding link provides a constant bias engagement between the friction surfaces of the holding link and the adjustment screws, so as to firmly hold the link in position and to eliminate any free play in the adjustment mechanism. The angular relationships between the adjustment screws, the angle support and the tapered friction surfaces of the weld nozzle holding link provide a geometric arrangement which permits precision adjustment of the holding link with respect to the angle support and also provides a solid holding link mount which is resistant to movement from outside forces.

  11. Unsteady transitions of separation patterns in single expansion ramp nozzle

    NASA Astrophysics Data System (ADS)

    Yu, Y.; Xu, J.; Yu, K.; Mo, J.

    2015-11-01

    The single expansion ramp nozzle is one of the optimal configurations for a planar rocket-based combined cycle engine because of its good integration and self-adaptability at off-design operation. The single expansion ramp nozzle is seriously overexpanded when the vehicle is at low speed, resulting in complex flow separation phenomena. Several separation patterns have been found in the single expansion ramp nozzle. Numerical simulations have shown that the transition between these separation patterns occurs in the nozzle startup and shutdown processes. However, only a few relevant experimental studies have been reported. This study reproduces the nozzle startup and shutdown processes using wind tunnel experiments. Two restricted shock separation patterns are observed in the experiment, namely, a separation bubble either forms on the ramp or the flap. The detailed flow fields in the transition processes are captured using a high-speed camera. The shock wave structures in the two separation patterns, influences of the nozzle pressure ratio (NPR) on the separation patterns and changes of the shock waves in the transition processes are discussed in detail. Shock wave instabilities accompany the separation transition, which usually takes less than 5 ms. The nozzle pressure ratios corresponding to the separation pattern transition are different in the startup and shutdown processes, which leads to a hysteresis effect.

  12. Possibilities of improving the performance of an autonomous cw chemical DF laser by replacing the slot nozzles by the ramp ones in the nozzle array

    SciTech Connect

    Bashkin, A S; Gurov, L V; Kurdyukov, M V

    2011-08-31

    The results of a comparative numerical study of the performance of an autonomous cw chemical DF laser are obtained by simulating the processes in the nozzles and laser cavity where several configurations of slot and ramp nozzle arrays are employed. Three-dimensional Navier-Stokes equations solved with the Ansys CFX software are used to describe the reacting multicomponent flow in the nozzles and laser cavity. To investigate lasing characteristics, a supplementary code is developed and is used to calculate the radiation intensity in the Fabry-Perot resonator, taking into account its nonuniform distribution along the aperture width and height. It is shown that the use of the nozzle array consisting of ramp nozzles, which, in contrast to the slot nozzles, provide enhanced mixing of the reactants makes it possible to improve the laser performance in the case of a high-pressure (more than 15 Torr) active medium. (control of radiation parameters)

  13. Computational Analyses of Offset Stream Nozzles for Noise Reduction

    NASA Technical Reports Server (NTRS)

    Dippold, Vance, III; Foster, Lancert; Wiese,Michael

    2007-01-01

    The Wind computational fluid dynamics code was used to perform a series of simulations on two offset stream nozzle concepts for jet noise reduction. The first concept used an S-duct to direct the secondary stream to the lower side of the nozzle. The second concept used vanes to turn the secondary flow downward. The analyses were completed in preparation of tests conducted in the NASA Glenn Research Center Aeroacoustic Propulsion Laboratory. The offset stream nozzles demonstrated good performance and reduced the amount of turbulence on the lower side of the jet plume. The computer analyses proved instrumental in guiding the development of the final test configurations and giving insight into the flow mechanics of offset stream nozzles. The computational predictions were compared with flowfield results from the jet rig testing and showed excellent agreement.

  14. Plasma separation from magnetic field lines in a magnetic nozzle

    NASA Technical Reports Server (NTRS)

    Kaufman, D. A.; Goodwin, D. G.; Sercel, J. C.

    1993-01-01

    This paper discusses conditions for separation of a plasma from the magnetic field of a magnetic nozzle. The analysis assumes a collisionless, quasineutral plasma, and therefore the results represent a lower bound on the amount of detachment possible for a given set of plasma conditions. We show that collisionless separation can occur because finite electron mass inhibits the flow of azimuthal currents in the nozzle. Separation conditions are governed by a parameter G which depends on plasma and nozzle conditions. Several methods of improving plasma detachment are presented, including moving the plasma generation zone downstream from the region of strongest magnetic field and using dual magnets to focus the plasma beam. Plasma detachment can be enhanced by manipulation of the nozzle configuration.

  15. RSRM Nozzle-to-Case Joint J-leg Development

    NASA Technical Reports Server (NTRS)

    Albrechtsen, Kevin U.; Eddy, Norman F.; Ewing, Mark E.; McGuire, John R.

    2003-01-01

    Since the beginning of the Space Shuttle Reusable Solid Rocket Motor (RSRM) program, nozzle-to-case joint polysulfide adhesive gas paths have occurred on several flight motors. These gas paths have allowed hot motor gases to reach the wiper O-ring. Even though these motors continue to fly safely with this condition, a desire was to reduce such occurrences. The RSRM currently uses a J-leg joint configuration on case field joints and igniter inner and outer joints. The J-leg joint configuration has been successfully demonstrated on numerous RSRM flight and static test motors, eliminating hot gas intrusion to the critical O-ring seals on these joints. Using the proven technology demonstrated on the case field joints and igniter joints, a nozzle-to-case joint J-leg design was developed for implementation on RSRM flight motors. This configuration provides an interference fit with nozzle fixed housing phenolics at assembly, with a series of pressurization gaps incorporated outboard of the joint mating surface to aid in joint pressurization and to eliminate any circumferential flow in this region. The joint insulation is bonded to the nozzle phenolics using the same pressure sensitive adhesive used in the case field joints and igniter joints. An enhancement to the nozzle-to-case joint J-leg configuration is the implementation of a carbon rope thermal barrier. The thermal barrier is located downstream of the joint bondline and is positioned within the joint in a manner where any hot gas intrusion into the joint passes through the thermal barrier, reducing gas temperatures to a level that would not affect O-rings downstream of the thermal barrier. This paper discusses the processes used in reaching a final nozzle-to-case joint J-leg design, provides structural and thermal results in support of the design, and identifies fabrication techniques and demonstrations used in arriving at the final configuration.

  16. Evaluation of Four Advanced Nozzle Concepts for Short Takeoff and Landing Performance

    NASA Technical Reports Server (NTRS)

    Quinto, P. Frank; Kemmerly, Guy T.; Paulson, John W., Jr.

    1993-01-01

    Four advanced nozzle concepts were tested on a canard-wing fighter in the Langley 14- by 22-Foot Subsonic Tunnel. The four vectoring-nozzle concepts were as follows: (1) an axisymmetric nozzle (AXI); (2) an asymmetric, load balanced exhaust nozzle (ALBEN); (3) a low aspect ratio, single expansion ramp nozzle (LASERN); and (4) a high aspect ratio, single expansion ramp nozzle (HASERN). The investigation was conducted to determine the most suitable nozzle concept for short takeoff and landing (STOL) performance. The criterion for the best STOL performance was a takeoff ground roll of less than 1000 ft. At approach, the criteria were high lift and sufficient drag to maintain a glide slope of -3 to -6 deg with enough pitching-moment control from the canards. The test was performed at a dynamic pressure of 45 lb/sq ft and an angle-of-attack range of 0 to 20 deg. The nozzle pressure ratio was varied from 1.0 to 4.3 at both dry power and after burning nozzle configurations with nozzle vectoring to 60 deg. In addition, the model was tested in and out of ground effects. The ALBEN concept was the best of the four nozzle concepts tested for STOL performance.

  17. Plasma spray nozzle with low overspray and collimated flow

    NASA Technical Reports Server (NTRS)

    Beason, Jr., George P. (Inventor); McKechnie, Timothy N. (Inventor); Power, Christopher A. (Inventor)

    1996-01-01

    An improved nozzle for reducing overspray in high temperature supersonic plasma spray devices comprises a body defining an internal passageway having an upstream end and a downstream end through which a selected plasma gas is directed. The nozzle passageway has a generally converging/diverging Laval shape with its upstream end converging to a throat section and its downstream end diverging from the throat section. The upstream end of the passageway is configured to accommodate a high current cathode for producing an electrical arc in the passageway to heat and ionize the gas flow to plasma form as it moves along the passageway. The downstream end of the nozzle is uniquely configured through the methodology of this invention to have a contoured bell-shape that diverges from the throat to the exit of the nozzle. Coating material in powder form is injected into the plasma flow in the region of the bell-shaped downstream end of the nozzle and the powder particles become entrained in the flow. The unique bell shape of the nozzle downstream end produces a plasma spray that is ideally expanded at the nozzle exit and thus virtually free of shock phenomena, and that is highly collimated so as to exhibit significantly reduced fanning and diffusion between the nozzle and the target. The overall result is a significant reduction in the amount of material escaping from the plasma stream in the form of overspray and a corresponding improvement in the cost of the coating operation and in the quality and integrity of the coating itself.

  18. Variable area exhaust nozzle

    NASA Technical Reports Server (NTRS)

    Johnston, E. A. (Inventor)

    1979-01-01

    An exhaust nozzle for a gas turbine engine comprises a number of arcuate flaps pivotally connected to the trailing edge of a cylindrical casing which houses the engine. Seals disposed within the flaps are spring biased and extensible beyond the side edges of the flaps. The seals of adjacent flaps are maintained in sealing engagement with each other when the flaps are adjusted between positions defining minimum nozzle flow area and the cruise position. Extensible, spring biased seals are also disposed within the flaps adjacent to a supporting pylon to thereby engage the pylon in a sealing arrangement. The flaps are hinged to the casing at the central portion of the flaps' leading edges and are connected to actuators at opposed outer portions of the leading edges to thereby maximize the mechanical advantage in the actuation of the flaps.

  19. Premixed direct injection nozzle

    DOEpatents

    Zuo, Baifang; Johnson, Thomas Edward; Lacy, Benjamin Paul; Ziminsky, Willy Steve

    2011-02-15

    An injection nozzle having a main body portion with an outer peripheral wall is disclosed. The nozzle includes a plurality of fuel/air mixing tubes disposed within the main body portion and a fuel flow passage fluidly connected to the plurality of fuel/air mixing tubes. Fuel and air are partially premixed inside the plurality of the tubes. A second body portion, having an outer peripheral wall extending between a first end and an opposite second end, is connected to the main body portion. The partially premixed fuel and air mixture from the first body portion gets further mixed inside the second body portion. The second body portion converges from the first end toward said second end. The second body portion also includes cooling passages that extend along all the walls around the second body to provide thermal damage resistance for occasional flame flash back into the second body.

  20. Atomizing nozzle and method

    DOEpatents

    Ting, Jason; Anderson, Iver E.; Terpstra, Robert L.

    2000-03-16

    A high pressure close-coupled gas atomizing nozzle includes multiple discrete gas jet discharge orifices having aerodynamically designed convergent-divergent geometry with an first converging section communicated to a gas supply manifold and to a diverging section by a constricted throat section to increase atomizing gas velocity. The gas jet orifices are oriented at gas jet apex angle selected relative to the melt supply tip apex angle to establish a melt aspiration condition at the melt supply tip.

  1. The Influence of Nozzle Shape on the Shock Structure in Separated Flows

    NASA Astrophysics Data System (ADS)

    Nasuti, F.; Onofri, M.; Pietropaoli, E.

    2005-02-01

    The performance of liquid rocket engines is presently limited by the side loads that take place during the startup because of the coupling between the natural flow asymmetry and a peculiar shock structure inside the nozzle. The shock and flow structures of highly overexpandend nozzles are examined numerically, with a critical discussion on the reasons yielding the different possible configurations. The results confirm that a major role is played by the flow gradients ahead of the shock and thus by the nozzle geometry. Key words: Nozzle; Flow separation; Mach reflection.

  2. Static internal performance of a two-dimensional convergent-divergent nozzle with thrust vectoring

    NASA Technical Reports Server (NTRS)

    Bare, E. Ann; Reubush, David E.

    1987-01-01

    A parametric investigation of the static internal performance of multifunction two-dimensional convergent-divergent nozzles has been made in the static test facility of the Langley 16-Foot Transonic Tunnel. All nozzles had a constant throat area and aspect ratio. The effects of upper and lower flap angles, divergent flap length, throat approach angle, sidewall containment, and throat geometry were determined. All nozzles were tested at a thrust vector angle that varied from 5.60 tp 23.00 deg. The nozzle pressure ratio was varied up to 10 for all configurations.

  3. Numerical Simulations of Canted Nozzle and Scarfed Nozzle Flow Fields

    NASA Astrophysics Data System (ADS)

    Javed, Afroz; Chakraborty, Debasis

    2016-06-01

    Computational fluid dynamics (CFD) techniques are used for the analysis of issues concerning non-conventional (canted and scarfed) nozzle flow fields. Numerical simulations are carried out for the quality of flow in terms of axisymmetric nature at the inlet of canted nozzles of a rocket motor. Two different nozzle geometries are examined. The analysis of these simulation results shows that the flow field at the entry of the nozzles is non axisymmetric at the start of the motor. With time this asymmetry diminishes, also the flow becomes symmetric before the nozzle throat, indicating no misalignment of thrust vector with the nozzle axis. The qualitative flow fields at the inlet of the nozzles are used in selecting the geometry with lesser flow asymmetry. Further CFD methodology is used to analyse flow field of a scarfed nozzle for the evaluation of thrust developed and its direction. This work demonstrates the capability of the CFD based methods for the nozzle analysis problems which were earlier solved only approximately by making simplifying assumptions and semi empirical methods.

  4. Shuttle subscale ablative nozzle tests

    NASA Technical Reports Server (NTRS)

    Powers, L. B.; Bailey, R. L.

    1980-01-01

    Recent subscale nozzle tests have identified new and promising carbon phenolic nozzle ablatives which utilize staple rayon, PAN, and pitch based carbon cloth. A 4-inch throat diameter submerged test nozzle designed for the 48-inch Jet Propulsion Laboratory char motor was used to evaluate five different designs incorporating 20 candidate ablatives. Test results indicate that several pitch and PAN-based carbon phenolic ablatives can provide erosion and char performance equivalent or superior to the present continuous rayon-based SRM ablative.

  5. A Survey of Challenges in Aerodynamic Exhaust Nozzle Technology for Aerospace Propulsion Applications

    NASA Technical Reports Server (NTRS)

    Shyne, Rickey J.

    2002-01-01

    The current paper discusses aerodynamic exhaust nozzle technology challenges for aircraft and space propulsion systems. Technology advances in computational and experimental methods have led to more accurate design and analysis tools, but many major challenges continue to exist in nozzle performance, jet noise and weight reduction. New generations of aircraft and space vehicle concepts dictate that exhaust nozzles have optimum performance, low weight and acceptable noise signatures. Numerous innovative nozzle concepts have been proposed for advanced subsonic, supersonic and hypersonic vehicle configurations such as ejector, mixer-ejector, plug, single expansion ramp, altitude compensating, lobed and chevron nozzles. This paper will discuss the technology barriers that exist for exhaust nozzles as well as current research efforts in place to address the barriers.

  6. Mach disk from underexpanded axisymmetric nozzle flow

    NASA Technical Reports Server (NTRS)

    Chang, I.-S.; Chow, W. L.

    1974-01-01

    The flowfield associated with the underexpanded axisymmetric nozzle freejet flow including the appearance of a Mach disk has been studied. It is shown that the location and size of the Mach disk are governed by the appearance of a triple-point shock configuration and the condition that the central core flow will reach a state of 'choking at a throat'. It is recognized that coalescence of waves requires special attention and the reflected wave, as well as the vorticity generated from these wave interactions, have to be taken accurately into account. The theoretical results obtained agreed well with the experimental data.

  7. Jet vectoring through nozzle asymmetry

    NASA Astrophysics Data System (ADS)

    Roh, Chris; Rosakis, Alexandros; Gharib, Morteza

    2015-11-01

    Previously, we explored the functionality of a tri-leaflet anal valve of a dragonfly larva. We saw that the dragonfly larva is capable of controlling the three leaflets independently to asymmetrically open the nozzle. Such control resulted in vectoring of the jet in various directions. To further understand the effect of asymmetric nozzle orifice, we tested jet flow through circular asymmetric nozzles. We report the relationship between nozzle asymmetry and redirecting of the jet at various Reynolds numbers. This material is based upon work supported by the National Science Foundation under Grant No. CBET-1511414; additional support by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469.

  8. Flow Energy Piezoelectric Bimorph Nozzle Harvester

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Lee, Hyeong Jae; Kim, Namhyo; Sun, Kai; Corbett, Gary; Walkemeyer, Phillip; Hasenoehrl, Jennifer; Hall, Jeffery L.; Colonius, Tim; Tosi, Luis Phillipe; Arrazola, Alvaro

    2014-01-01

    There is a need for a long-life power generation scheme that could be used downhole in an oil well to produce 1 Watt average power. There are a variety of existing or proposed energy harvesting schemes that could be used in this environment but each of these has its own limitations. The vibrating piezoelectric structure is in principle capable of operating for very long lifetimes (decades) thereby possibly overcoming a principle limitation of existing technology based on rotating turbo-machinery. In order to determine the feasibility of using piezoelectrics to produce suitable flow energy harvesting, we surveyed experimentally a variety of nozzle configurations that could be used to excite a vibrating piezoelectric structure in such a way as to enable conversion of flow energy into useful amounts of electrical power. These included reed structures, spring mass-structures, drag and lift bluff bodies and a variety of nozzles with varying flow profiles. Although not an exhaustive survey we identified a spline nozzle/piezoelectric bimorph system that experimentally produced up to 3.4 mW per bimorph. This paper will discuss these results and present our initial analyses of the device using dimensional analysis and constitutive electromechanical modeling. The analysis suggests that an order-of-magnitude improvement in power generation from the current design is possible.

  9. Application of DPIV to Enhanced Mixing Heated Nozzle Flows

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.; Bridges, James

    2002-01-01

    Digital Particle Imaging Velocimetry (DPIV) is a planar velocity measurement technique that continues to be applied to new and challenging engineering research facilities while significantly reducing facility test time. DPIV was used in the GRC Nozzle Acoustic Test Rig (NATR) to characterize the high temperature (560 C), high speed (is greater than 500 m/s) flow field properties of mixing enhanced jet engine nozzles. The instantaneous velocity maps obtained using DPIV were used to determine mean velocity, rms velocity and two-point correlation statistics to verify the true turbulence characteristics of the flow. These measurements will ultimately be used to properly validate aeroacoustic model predictions by verifying CFD input to these models. These turbulence measurements have previously not been possible in hot supersonic jets. Mapping the nozzle velocity field using point based techniques requires over 60 hours of test time, compared to less than 45 minutes using DPIV, yielding a significant reduction in testing time. A dual camera DPIV configuration was used to maximize the field of view and further minimize the testing time required to map the nozzle flow. The DPIV system field of view covered 127 by 267 mm. Data were acquired at 19 axial stations providing coverage of the flow from the nozzle exit to 2.37 in downstream. At each measurement station, 400 image frame pairs were acquired from each camera. The DPIV measurements of the mixing enhanced nozzle designs illustrate the changes in the flow field resulting in the reduced noise signature.

  10. Performance of Several Conical Convergent-Divergent Rocket-Type Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Campbell, C. E.; Farley, J. M.

    1960-01-01

    An investigation was conducted to obtain nozzle performance data with relatively large-scale models at pressure ratios as high as 120. Conical convergent-divergent nozzles with divergence angles alpha of 15, 25, and 29 deg. were each tested at area ratios of approximately 10, 25, and 40. Heated air (1200 F) was supplied at the nozzle inlet at pressures up to 145 pounds per square inch absolute and was exhausted into quiescent air at pressures as low as 1.2 pounds per square inch absolute. Thrust ratios for all nozzle configurations are presented over the range of pressure ratios attainable and were extrapolated when possible to design pressure ratio and beyond. Design thrust ratios decreased with increasing nozzle divergence angle according to the trend predicted by the (1 + cos alpha)/2 parameter. Decreasing the nozzle divergence angle resulted in sizable increases in thrust ratio for a given surface-area ratio (nozzle weight), particularly at low nozzle pressure ratios. Correlations of the nozzle static pressure at separation and of the average static pressure downstream of separation with various nozzle parameters permitted the calculation of thrust in the separated-flow region from unseparated static-pressure distributions. Thrust ratios calculated by this method agreed with measured values within about 1 percent.

  11. Computational Analysis of a Pylon-Chevron Core Nozzle Interaction

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Kinzie, Kevin W.; Pao, S. Paul

    2001-01-01

    In typical engine installations, the pylon of an engine creates a flow disturbance that interacts with the engine exhaust flow. This interaction of the pylon with the exhaust flow from a dual stream nozzle was studied computationally. The dual stream nozzle simulates an engine with a bypass ratio of five. A total of five configurations were simulated all at the take-off operating point. All computations were performed using the structured PAB3D code which solves the steady, compressible, Reynolds-averaged Navier-Stokes equations. These configurations included a core nozzle with eight chevron noise reduction devices built into the nozzle trailing edge. Baseline cases had no chevron devices and were run with a pylon and without a pylon. Cases with the chevron were also studied with and without the pylon. Another case was run with the chevron rotated relative to the pylon. The fan nozzle did not have chevron devices attached. Solutions showed that the effect of the pylon is to distort the round Jet plume and to destroy the symmetrical lobed pattern created by the core chevrons. Several overall flow field quantities were calculated that might be used in extensions of this work to find flow field parameters that correlate with changes in noise.

  12. Emissions and Cost Implications of Controlled Electric Vehicle Charging in the U.S. PJM Interconnection.

    PubMed

    Weis, Allison; Michalek, Jeremy J; Jaramillo, Paulina; Lueken, Roger

    2015-05-01

    We develop a unit commitment and economic dispatch model to estimate the operation costs and the air emissions externality costs attributable to new electric vehicle electricity demand under controlled vs uncontrolled charging schemes. We focus our analysis on the PJM Interconnection and use scenarios that characterize (1) the most recent power plant fleet for which sufficient data are available, (2) a hypothetical 2018 power plant fleet that reflects upcoming plant retirements, and (3) the 2018 fleet with increased wind capacity. We find that controlled electric vehicle charging can reduce associated generation costs by 23%-34% in part by shifting loads to lower-cost, higher-emitting coal plants. This shift results in increased externality costs of health and environmental damages from increased air pollution. On balance, we find that controlled charging of electric vehicles produces negative net social benefits in the recent PJM grid but could have positive net social benefits in a future grid with sufficient coal retirements and wind penetration.

  13. Fuel injection nozzle

    SciTech Connect

    Kato, M.; Tojo, S.; Arai, K.

    1986-07-22

    A fuel injection nozzle is described connected to a fuel injection pump to inject fuel into a combustion chamber of an internal combustion engine consisting of: a nozzle housing defining therein a fuel sump chamber, an injection hole communicating with the sump chamber and opened at the outer surface of the nozzle housing, a stepped cylinder bore having a smaller diameter bore section and a larger diameter bore section and a fuel passage communicating at one end with the sump chamber and at the other end with the smaller diameter bore section of the stepped cylinder bore; a stepped plunger fitted in the stepped cylinder bore and having a smaller diameter plunger section fitted into the smaller diameter bore section and a larger diameter plunger section fitted into the larger diameter bore section in which the smaller diameter bore section together with the end face of the smaller diameter plunger section defines a pump chamber communicating with the fuel passage and the larger diameter bore section together with the end face of the larger diameter plunger section defines a main fuel chamber into which a main fuel is supplied from the fuel injection pump; auxiliary fuel supply means for supplying an auxiliary fuel into the sump chamber and pump chamber through the fuel passage; valve means for opening and closing an injection hole; communication means for permitting the main fuel chamber to communicate with the fuel passage when the main fuel is supplied from the injection pump into the main fuel chamber to cause the stepped plunger to be moved a predetermined distance in a direction in which the auxiliary fuel in the pump chamber is pressurized.

  14. 77 FR 61593 - North American Natural Resources, Inc. Complainant v. PJM Interconnection, L.L.C, American...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission North American Natural Resources, Inc. Complainant v. PJM Interconnection, L... Federal Power Act (FPA), 16 U.S.C. 824(e), North American Natural Resource, Inc. (NSANR) filed a...

  15. 77 FR 10502 - PJM Interconnection, L.L.C.; Notice Establishing Post-Staff Technical Conference Comment Period

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Interconnection, L.L.C.; Notice Establishing Post-Staff Technical Conference Comment Period As indicated in the February 2, 2012 Supplement Notice, Supplemental Notice...

  16. 77 FR 23475 - PJM Interconnection, L.L.C., Duke Energy Ohio, Inc., Duke Energy Kentucky, Inc; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission PJM Interconnection, L.L.C., Duke Energy Ohio, Inc., Duke Energy Kentucky, Inc; Notice of Filing Take notice that on April 5, 2012, Duke Energy Ohio, Inc. and Duke...

  17. 78 FR 24192 - J.P. Morgan Ventures Energy Corp. v. Midwest Independent System Operator, Inc. PJM...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission J.P. Morgan Ventures Energy Corp. v. Midwest Independent System Operator, Inc. PJM Interconnection, L.L.C.; Notice of Complaint Take notice that on April 10, 2013, J.P....

  18. 78 FR 67357 - Vineland Municipal Electric Utility v. Atlantic City Electric Company PJM Interconnection, L.L.C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-12

    ... Interconnection, L.L.C.; Notice of Complaint Take notice that on November 1, 2013, pursuant to sections 205, 206... City Electric Company and PJM Interconnection, L.L.C. (Respondents). Vineland seeks an order granting full and immediate refunds of all amounts paid in violation of the Interconnection Agreement and...

  19. Industrial jet noise: Coanda nozzles

    NASA Astrophysics Data System (ADS)

    Li, P.; Halliwell, N. A.

    1985-04-01

    Within the U.K. manufacturing industries noise from industrial jets ranks third as a major contributor to industrial deafness. Noise control is hindered because use is made of the air once it has exuded from the nozzle exit. Important tasks include swarf removal, paint spreading, cooling, etc. Nozzles which employ the Coanda effect appear to offer the possibility of significant noise reduction whilst maintaining high thrust efficiency when compared with the commonly used simple open pipe or ordinary convergent nozzle. In this paper the performance of Coanda-type nozzles is examined in detail and an index rating for nozzle performance is introduced. Results show that far field stagnation pressure distributions are Gaussian and similar in all cases with a dispersion coefficient σ = 0·64. Noise reduction and thrust efficiency are shown to be closely related to the design geometry of the central body of the nozzle. Performance is based on four fundamental characteristics, these being the noise level at 1 m from the exit and at a 90° station to the nozzle axis, and the thrust on a chosen profile, the noise reduction and the thrust efficiency. Physically, performance is attributed to flow near field effects where, although all nozzles are choked, shock cell associated noise is absent.

  20. Nozzle insert for mixed mode fuel injector

    DOEpatents

    Lawrence, Keith E.

    2006-11-21

    A fuel injector includes a homogenous charge nozzle outlet set and a conventional nozzle outlet set controlled respectively, by first and second needle valve members. The homogeneous charged nozzle outlet set is defined by a nozzle insert that is attached to an injector body, which defines the conventional nozzle outlet set. The nozzle insert is a one piece metallic component with a large diameter segment separated from a small diameter segment by an annular engagement surface. One of the needle valve members is guided on an outer surface of the nozzle insert, and the nozzle insert has an interference fit attachment to the injector body.

  1. Internal performance of a 10 deg conical plug nozzle with a multispoke primary and translating external shroud

    NASA Technical Reports Server (NTRS)

    Bresnahan, D. L.

    1972-01-01

    An experimental investigation was conducted in a nozzle static test facility to determine the performance characteristics of a cold-flow, 21.59-centimeter-diameter plug nozzle with a multispoke primary. Two multispoke primary nozzles, a 12-spoke and a 24-spoke, were tested and compared with an annular plug nozzle. The supersonic cruise configurations for both spoke primaries performed about the same, with a gross thrust coefficient of 0.974, a decrease of approximately 1.5 percent from the reference nozzle. The takeoff configuration for the 12-spoke primary had a gross thrust coefficient of 0.957, a decrease of 1.5 percent from the reference nozzle, and the 24-spoke primary had a gross thrust coefficient of 0.95.

  2. Multiple Exhaust Nozzle Effects on J-2X Gas Generator Outlet Impedance

    NASA Technical Reports Server (NTRS)

    Kenny, R. Jeremy; Muss, Jeffrey; Hulka, James R.; Casiano, Matthew

    2010-01-01

    The current test setup of the J-2X gas generator system uses a multiple nozzle configuration to exhaust hot gases to drive the propellant supply turbines. Combustion stability assessment of this gas generator design requires knowledge of the impedance effects the multiple nozzle configuration creates on the combustion chamber acoustic modes. Parallel work between NASA and Sierra Engineering is presented, showing two methods used to calculate the effective end impedance resulting from multiple nozzle configurations. The NASA method is a simple estimate of the effective impedance using the long wavelength approximation. Sierra Engineering has developed a more robust numerical integration method implemented in ROCCID to accommodate for multiple nozzles. Analysis using both methods are compared to J-2X gas generator test data collected over the past year.

  3. Installed Transonic 2D Nozzle Nacelle Boattail Drag Study

    NASA Technical Reports Server (NTRS)

    Malone, Michael B.; Peavey, Charles C.

    1999-01-01

    The Transonic Nozzle Boattail Drag Study was initiated in 1995 to develop an understanding of how external nozzle transonic aerodynamics effect airplane performance and how strongly those effects are dependent on nozzle configuration (2D vs. axisymmetric). MDC analyzed the axisymmetric nozzle. Boeing subcontracted Northrop-Grumman to analyze the 2D nozzle. AU participants analyzed the AGARD nozzle as a check-out and validation case. Once the codes were checked out and the gridding resolution necessary for modeling the separated flow in this region determined, the analysis moved to the installed wing/body/nacelle/diverter cases. The boat tail drag validation case was the AGARD B.4 rectangular nozzle. This test case offered both test data and previous CFD analyses for comparison. Results were obtained for test cases B.4.1 (M=0.6) and B.4.2 (M=0.938) and compared very well with the experimental data. Once the validation was complete a CFD grid was constructed for the full Ref. H configuration (wing/body/nacelle/diverter) using a combination of patched and overlapped (Chimera) grids. This was done to ensure that the grid topologies and density would be adequate for the full model. The use of overlapped grids allowed the same grids from the full configuration model to be used for the wing/body alone cases, thus eliminating the risk of grid differences affecting the determination of the installation effects. Once the full configuration model was run and deemed to be suitable the nacelle/diverter grids were removed and the wing/body analysis performed. Reference H wing/body results were completed for M=0.9 (a=0.0, 2.0, 4.0, 6.0 and 8.0), M=1.1 (a=4.0 and 6.0) and M=2.4 (a=0.0, 2.0, 4.4, 6.0 and 8.0). Comparisons of the M=0.9 and M=2.4 cases were made with available wind tunnel data and overall comparisons were good. The axi-inlet/2D nozzle nacelle was analyzed isolated. The isolated nacelle data coupled with the wing/body result enabled the interference effects of the

  4. A Computational Study of a New Dual Throat Fluidic Thrust Vectoring Nozzle Concept

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.; Berrier, Bobby L.; Flamm, Jeffrey D.; Johnson, Stuart K.

    2005-01-01

    A computational investigation of a two-dimensional nozzle was completed to assess the use of fluidic injection to manipulate flow separation and cause thrust vectoring of the primary jet thrust. The nozzle was designed with a recessed cavity to enhance the throat shifting method of fluidic thrust vectoring. Several design cycles with the structured-grid, computational fluid dynamics code PAB3D and with experiments in the NASA Langley Research Center Jet Exit Test Facility have been completed to guide the nozzle design and analyze performance. This paper presents computational results on potential design improvements for best experimental configuration tested to date. Nozzle design variables included cavity divergence angle, cavity convergence angle and upstream throat height. Pulsed fluidic injection was also investigated for its ability to decrease mass flow requirements. Internal nozzle performance (wind-off conditions) and thrust vector angles were computed for several configurations over a range of nozzle pressure ratios from 2 to 7, with the fluidic injection flow rate equal to 3 percent of the primary flow rate. Computational results indicate that increasing cavity divergence angle beyond 10 is detrimental to thrust vectoring efficiency, while increasing cavity convergence angle from 20 to 30 improves thrust vectoring efficiency at nozzle pressure ratios greater than 2, albeit at the expense of discharge coefficient. Pulsed injection was no more efficient than steady injection for the Dual Throat Nozzle concept.

  5. Experimental and analytical investigation of axisymmetric supersonic cruise nozzle geometry at Mach numbers from 0.60 to 1.30

    NASA Technical Reports Server (NTRS)

    Carson, G. T., Jr.; Lee, E. E., Jr.

    1981-01-01

    Quantitative pressure and force data for five axisymmetric boattail nozzle configurations were examined. These configurations simulate the variable-geometry feature of a single nozzle design operating over a range of engine operating conditions. Five nozzles were tested in the Langley 16-Foot Transonic Tunnel at Mach numbers from 0.60 to 1.30. The experimental data were also compared with theoretical predictions.

  6. Viscous three-dimensional analyses for nozzles for hypersonic propulsion

    NASA Technical Reports Server (NTRS)

    Harloff, G. J.; Reddy, D. R.; Lai, H. T.

    1990-01-01

    A Navier-Stokes computer code was validated using a number of two- and three-dimensional configurations for both laminar and turbulent flows. The validation data covers a range of freestream Mach numbers from 3 to 14, includes wall pressures, velocity profiles, and skin friction. Nozzle flow fields computed for a generic scramjet nozzle from Mach 3 to 20, wall pressures, wall skin friction values, heat transfer values, and overall performance are presented. In addition, three-dimensional solutions obtained for two asymmetric, single expansion ramp nozzles at a pressure ratio of 10 consists of the internal expansion region in the converging/diverging sections and the external supersonic exhaust in a quiescent ambient environment. The fundamental characteristics that were captured successfully include expansion fans; Mach wave reflections; mixing layers; and nonsymmetrical, multiple inviscid cell, supersonic exhausts. Comparison with experimental data for wall pressure distributions at the center planes shows good agreement.

  7. Experimental evaluation of a translating nozzle sidewall radial turbine

    NASA Technical Reports Server (NTRS)

    Roelke, Richard J.; Rogo, Casimir

    1987-01-01

    Studies have shown that reduced specific fuel consumption of rotorcraft engines can be achieved with a variable capacity engine. A key component in such an engine in a high-work, high-temperature variable geometry gas generator turbine. An optimization study indicated that a radial turbine with a translating nozzle sidewall could produce high efficiency over a wide range of engine flows but substantiating data were not available. An experimental program with Teledyne CAE, Toledo, Ohio was undertaken to evaluate the moving sidewall concept. A variety of translating nozzle sidewall turbine configurations were evaluated. The effects of nozzle leakage and coolant flows were also investigated. Testing was done in warm air (121 C). The results of the contractual program were summarized.

  8. Free-jet acoustic investigation of high-radius-ratio coannular plug nozzles. Comprehensive data report, volume 1

    NASA Technical Reports Server (NTRS)

    Knott, P. R.; Janardan, B. A.; Majjigi, R. K.; Shutiani, P. K.; Vogt, P. G.

    1981-01-01

    Six coannular plug nozzle configurations having inverted velocity and temperature profiles, and a baseline convergent conical nozzle were tested for simulated flight acoustic evaluation in General Electric's Anechoic Free-Jet Acoustic Facility. The nozzles were tested over a range of test conditions that are typical of a Variable Cycle Engine for application to advanced high speed aircraft. The outer stream radius ratio for most of the configurations was 0.853, and the inner-stream-outer-stream area ratio was tested in the range of 0.54. Other variables investigated were the influence of bypass struts, a simple noncontoured convergent-divergent outer stream nozzle for forward quadrant shock noise control, and the effects of varying outer stream radius and inner-stream-to-outer-stream velocity ratios on the flight noise signatures of the nozzles. It was found that in simulated flight, the high-radius-ratio coannular plug nozzles maintain their jet noise and shock noise reduction features previously observed in static testing. The presence of nozzle bypass structs will not significantly effect the acoustic noise reduction features of a General Electric-type nozzle design. A unique coannular plug nozzle flight acoustic spectral prediction method was identified and found to predict the measured results quite well. Special laser velocimeter and acoustic measurements were performed which have given new insight into the jet and shock noise reduction mechanisms of coannular plug nozzles with regard to identifying further beneficial research efforts.

  9. Free-jet acoustic investigation of high-radius-ratio coannular plug nozzles

    NASA Technical Reports Server (NTRS)

    Knott, P. R.; Janardan, B. A.; Majjigi, R. K.; Bhutiani, P. K.; Vogt, P. G.

    1984-01-01

    The experimental and analytical results of a scale model simulated flight acoustic exploratory investigation of high radius ratio coannular plug nozzles with inverted velocity and temperature profiles are summarized. Six coannular plug nozzle configurations and a baseline convergent conical nozzle were tested for simulated flight acoustic evaluation. The nozzles were tested over a range of test conditions that are typical of a Variable Cycle Engine for application to advanced high speed aircraft. It was found that in simulate flight, the high radius ratio coannular plug nozzles maintain their jet noise and shock noise reduction features previously observed in static testing. The presence of nozzle bypass struts will not significantly affect the acousticn noise reduction features of a General Electric type nozzle design. A unique coannular plug nozzle flight acoustic spectral prediction method was identified and found to predict the measured results quite well. Special laser velocimeter and acoustic measurements were performed which have given new insights into the jet and shock noise reduction mechanisms of coannular plug nozzles with regard to identifying further benificial research efforts.

  10. Computational Study of an Axisymmetric Dual Throat Fluidic Thrust Vectoring Nozzle for a Supersonic Aircraft Application

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.; Flamm, Jeffrey D.; Berrier, Bobby L.; Johnson, Stuart K.

    2007-01-01

    A computational investigation of an axisymmetric Dual Throat Nozzle concept has been conducted. This fluidic thrust-vectoring nozzle was designed with a recessed cavity to enhance the throat shifting technique for improved thrust vectoring. The structured-grid, unsteady Reynolds- Averaged Navier-Stokes flow solver PAB3D was used to guide the nozzle design and analyze performance. Nozzle design variables included extent of circumferential injection, cavity divergence angle, cavity length, and cavity convergence angle. Internal nozzle performance (wind-off conditions) and thrust vector angles were computed for several configurations over a range of nozzle pressure ratios from 1.89 to 10, with the fluidic injection flow rate equal to zero and up to 4 percent of the primary flow rate. The effect of a variable expansion ratio on nozzle performance over a range of freestream Mach numbers up to 2 was investigated. Results indicated that a 60 circumferential injection was a good compromise between large thrust vector angles and efficient internal nozzle performance. A cavity divergence angle greater than 10 was detrimental to thrust vector angle. Shortening the cavity length improved internal nozzle performance with a small penalty to thrust vector angle. Contrary to expectations, a variable expansion ratio did not improve thrust efficiency at the flight conditions investigated.

  11. Free-jet investigation of mechanically suppressed, high radius ratio coannular plug model nozzles

    NASA Technical Reports Server (NTRS)

    Janardan, B. A.; Majjigi, R. K.; Brausch, J. F.; Knott, P. R.

    1985-01-01

    The experimental and analytical acoustic results of a scale-model investigation or unsuppressed and mechanically suppressed high-radius ratio coannular plug nozzles with inverted velocity and temperature profiles are summarized. Nine coannular nozzle configurations along with a reference conical nozzle were evaluated in the Anechoic Free-Jet Facility for a total of 212 acoustic test points. Most of the tests were conducted at variable cycle engine conditions applicable to advanced high speed aircraft. The tested nozzles included coannular plug nozzles with both convergent and convergent-divergent (C-D) terminations in order to evaluate C-D effectiveness in the reduction of shock-cell noise and 20 and 40 shallow-chute mechanical suppressors in the outer stream in order to evaluate their effectiveness in the reduction of jet noise. In addition to the acoustic tests, mean and turbulent velocity measurements were made on selected plumes of the 20 shallow-chute configuration using a laser velocimeter. At a mixed jet velocity of 700 m/sec, the 20 shallow-chute suppressor configuration yielded peak aft quadrant suppression of 11.5 and 9 PNdB and forward quadrant suppression of 7 and 6 PNdB relative to a baseline conical nozzles during static and simulated flight, respectively. The C-D terminations were observed to reduce shock-cell noise. An engineering spectral prediction method was formulated for mechanically suppressed coannular plug nozzles.

  12. Characterization of anguibactin, a novel siderophore from Vibrio anguillarum 775(pJM1).

    PubMed Central

    Actis, L A; Fish, W; Crosa, J H; Kellerman, K; Ellenberger, S R; Hauser, F M; Sanders-Loehr, J

    1986-01-01

    Anguibactin, a siderophore produced by cells of Vibrio anguillarum 775 harboring the pJM1 plasmid, has now been isolated from the supernatants of iron-deficient cultures. This iron-reactive material was purified by adsorption onto an XAD-7 resin and subsequent gel filtration on a Sephadex LH-20 column. The resulting neutral compound produced an ion at m/z 348 in mass spectrometry and contained one sulfur, four oxygen, and four nitrogen atoms as determined by elemental analysis. Its strong UV absorbance and blue fluorescence were suggestive of a phenolic moiety. In colorimetric reactions anguibactin behaved like a catechol. The catechol assignment was supported by the appearance of a new absorption band at 510 nm in the ferric complex and by the appearance of peaks at 1,367, 1,447, 1,469, and 1,538 cm-1 in the resonance Raman spectrum. In addition, the infrared spectrum gave evidence of a secondary amide function, but no free carboxylic acid or hydroxamic acid groups were observed. A third iron-ligating group was suggested by the liberation of three protons during iron binding; mass spectrometry of the resulting material yielded a molecular ion characteristic of a 1:1 complex of ferric anguibactin. The purified anguibactin exhibited specific growth-promoting activity under iron-limiting conditions for a siderophore-deficient mutant of V. anguillarum 775(pJM1). A novel structure for anguibactin was indicated by the failure of a large number of known siderophores and synthetic chelators to yield a similar type of specific cross-feeding in the V. anguillarum bioassay. PMID:3013839

  13. Effect of geometrical parameters on submerged cavitation jet discharged from profiled central-body nozzle

    NASA Astrophysics Data System (ADS)

    Yang, Minguan; Xiao, Shengnan; Kang, Can; Wang, Yuli

    2013-05-01

    The flow characteristics of cavitation jets are essential issues among relevant studies. The physical properties of the jet are largely determined by the geometrical parameters of the nozzle. The structure and cavitation jets characteristics of the angular-nozzle and the self-resonating cavitation nozzle have been extensively studied, but little research is conducted in the central-body cavitation nozzle mainly because of its hard processing and the cavitation jet effect not satisfactory. In this paper, a novel central-body nozzle (a non-plunger central-body nozzle with square outlet) is studied to solve above problems. Submerged jets discharged from the novel central-body nozzle are simulated, employing the full cavitation model. The impact of nozzle configuration on jet properties is analyzed. The analysis results indicate that when central-body relative diameter keeps constant, there is an optimal contraction degree of nozzle's outlet, which can induce intense cavitation in the jet. The central-body relative diameter also affects jet profiles. In the case of large central-body relative diameter, most of the bubbles settle in the jet core. On the contrary, a smaller relative diameter makes bubbles concentrate in the interface between the jet and its surrounding fluid. Moreover, the shorter outlet part allows the cavitation zone further extend in both the axial and racial directions. The research results further consummate the study on the central-body nozzles and the correlation between cavitation jet and the structure, and elementarily reveal the mechanism of cavitation jet produced in a non-plunger novel central-body nozzle and the effect of the structure parameters on the cavitation jet, moreover, provide the theoretical basis for the optimal design of the nozzle.

  14. Injection nozzle for a turbomachine

    SciTech Connect

    Uhm, Jong Ho; Johnson, Thomas Edward; Kim, Kwanwoo

    2012-09-11

    A turbomachine includes a compressor, a combustor operatively connected to the compressor, an end cover mounted to the combustor, and an injection nozzle assembly operatively connected to the combustor. The injection nozzle assembly includes a first end portion that extends to a second end portion, and a plurality of tube elements provided at the second end portion. Each of the plurality of tube elements defining a fluid passage includes a body having a first end section that extends to a second end section. The second end section projects beyond the second end portion of the injection nozzle assembly.

  15. Airfoil nozzle and shroud assembly

    DOEpatents

    Shaffer, James E.; Norton, Paul F.

    1997-01-01

    An airfoil and nozzle assembly including an outer shroud having a plurality of vane members attached to an inner surface and having a cantilevered end. The assembly further includes a inner shroud being formed by a plurality of segments. Each of the segments having a first end and a second end and having a recess positioned in each of the ends. The cantilevered end of the vane member being positioned in the recess. The airfoil and nozzle assembly being made from a material having a lower rate of thermal expansion than that of the components to which the airfoil and nozzle assembly is attached.

  16. Airfoil nozzle and shroud assembly

    DOEpatents

    Shaffer, J.E.; Norton, P.F.

    1997-06-03

    An airfoil and nozzle assembly are disclosed including an outer shroud having a plurality of vane members attached to an inner surface and having a cantilevered end. The assembly further includes a inner shroud being formed by a plurality of segments. Each of the segments having a first end and a second end and having a recess positioned in each of the ends. The cantilevered end of the vane member being positioned in the recess. The airfoil and nozzle assembly being made from a material having a lower rate of thermal expansion than that of the components to which the airfoil and nozzle assembly is attached. 5 figs.

  17. NERVA nozzle design status report

    NASA Technical Reports Server (NTRS)

    Williams, J. J.; Pickering, J. L.; Ackerman, R. G.

    1972-01-01

    The results of the design analyses are presented along with the status of the attained design maturity of the structural elements of the nozzle jacket and various aspects of the coolant passages. The design analyses relating to the nozzle shell were based on design allowables as supported by cursory values obtained from ARMCO 22-13-5 nozzle forgings. The major aspects of the coolant passages considered include: low cycle thermal fatigue, ability to operate at 4500 R gas temperature, tube buckling, and susceptibility to erosion. The scope of the analysis is limited to processes leading to reliability assessments of failure mechanisms.

  18. Free jet feasibility study of a thermal acoustic shield concept for AST/VCE application-dual flow. Comprehensive data report. Volume 1: Test nozzles and acoustic data

    NASA Technical Reports Server (NTRS)

    Janardan, B. A.; Brausch, J. F.; Price, A. O.

    1984-01-01

    Acoustic and diagnostic data that were obtained to determine the influence of selected geometric and aerodynamic flow variables of coannular nozzles with thermal acoustic shields are summarized in this comprehensive data report. A total of 136 static and simulated flight acoustic test points were conducted with 9 scale-model nozzles The tested nozzles included baseline (unshielded), 180 deg shielded, and 360 deg shielded dual flow coannular plug configurations. The baseline configurations include a high radius ratio unsuppressed coannular plug nozzle and a coanuular plug nozzle and a coannular plug nozzle with a 20-chute outer stream suppressor. The tests were conducted at nozzle temperatures and pressure typical of operating conditions of variable cycle engine.

  19. Spreading characteristics and thrust of jets from asymmetric nozzles

    NASA Technical Reports Server (NTRS)

    Zaman, K. B. M. Q.

    1995-01-01

    The spreading characteristics of jets from several asymmetric nozzles are studied in comparison to those of an axisymmetric jet, over the Mach number (M(sub J)) range of 0.3 to 1.96. The effect of tabs in two cases, the axisymmetric nozzle fitted with four tabs and a rectangular nozzle fitted with two large tabs, is also included in the comparison. Compared to the axisymmetric jet, the asymmetric jets spread only slightly faster at subsonic conditions, while at supersonic conditions, when screech occurs, they spread much faster. Screech profoundly increases the spreading of all jets. The effect varies in the different stages of screech, and the corresponding unsteady flowfield characteristics are documented via phase-averaged measurement of the fluctuating total pressure. An organization and intensification of the azimuthal vortical structures under the screeching condition is believed to be responsible for the increased spreading. Curiously, the jet from a 'lobed mixer' nozzle spreads much less at supersonic conditions compared to all other cases. This is due to the absence of screech with this nozzle. Jet spreading for the two tab configurations, on the other hand, is significantly more than any of the no-tab cases. This is true in the subsonic regime, as well as in the supersonic regime in spite of the fact that screech is essentially eliminated by the tabs. The dynamics of the streamwise vortex pairs produced by the tabs cause the most efficient jet spreading thus far observed in the study.

  20. Hook nozzle arrangement for supporting airfoil vanes

    SciTech Connect

    Shaffer, James E.; Norton, Paul F.

    1996-01-01

    A gas turbine engine's nozzle structure includes a nozzle support ring, a plurality of shroud segments, and a plurality of airfoil vanes. The plurality of shroud segments are distributed around the nozzle support ring. Each airfoil vane is connected to a corresponding shroud segment so that the airfoil vanes are also distributed around the nozzle support ring. Each shroud segment has a hook engaging the nozzle support ring so that the shroud segments and corresponding airfoil vanes are supported by the nozzle support ring. The nozzle support ring, the shroud segments, and the airfoil vanes may be ceramic.

  1. Hook nozzle arrangement for supporting airfoil vanes

    DOEpatents

    Shaffer, J.E.; Norton, P.F.

    1996-02-20

    A gas turbine engine`s nozzle structure includes a nozzle support ring, a plurality of shroud segments, and a plurality of airfoil vanes. The plurality of shroud segments are distributed around the nozzle support ring. Each airfoil vane is connected to a corresponding shroud segment so that the airfoil vanes are also distributed around the nozzle support ring. Each shroud segment has a hook engaging the nozzle support ring so that the shroud segments and corresponding airfoil vanes are supported by the nozzle support ring. The nozzle support ring, the shroud segments, and the airfoil vanes may be ceramic. 8 figs.

  2. Calculations of low Reynolds number rocket nozzles

    NASA Technical Reports Server (NTRS)

    Kim, Suk C.

    1993-01-01

    The performance of low-thrust rocket nozzles was studied with a full Navier-Stokes code. The effect of the reduction of the nozzle length on the viscous loss and on the two-dimensional loss due to the increase in the nozzle exit angle was examined by calculating the flowfield and performance values of hydrogen resistojet nozzle with various lengths and shapes (such as 20-deg or 30-deg conical nozzles and a nozzle whose wall contour is given by the Rao nozzle optimization code). It was found that the vacuum specific impulse value of the 30-deg conical nozzle was the highest and that of the contoured nozzle was the lowest among the three nozzles, whose throat Reynolds number and area ratio were 1150 and 82, respectively.

  3. Evaporation Tower With Prill Nozzles

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1984-01-01

    Tower more efficient than conventional evaporation equipment. Liquids such as milk and fruit juice concentrated by passing them through tiny nozzle to form droplets, then allowing droplets to fall through evacuated tower with cooled walls.

  4. Gas nozzle adapter

    SciTech Connect

    Bunce, E.B.

    1993-08-24

    A gasoline nozzle is described for connection to a gasoline pump through a gasoline delivery hose, said nozzle comprising: (a) a housing which contains a normally closed valve, (b) a trigger mechanism on said housing for opening said valve, (c) a rigid cylindrical tube having an inner end which is operatively connected to said valve and an outer open end, (d) an outer annular protuberance on said tube between said inner and outer ends, (e) a flexible gasoline fume return hose which surrounds said rigid tube, said fume return hose having an inner end which is fixed to said housing and an outer open end which is normally biased into alignment with the outer open end of said rigid tube, said fume return hose being compressible from its outer end for movement along the length of said rigid tube from the outer end of the rigid tube to a position between the housing and said protuberance, (f) a control mechanism to prevent said valve from being opened by said trigger mechanism when said fume return hose is at its normal extended position and to enable said valve to be opened by said trigger mechanism when said fume return hose is compressed so that the outer end of the fume return hose is at said position between the housing and said protuberance, and (g) an adapter comprising a main body portion which has a slot and an opening to the slot and a handle which is fixed to said main body portion to enable said main body portion to be interposed between said protuberance and the outer end of said fume return hose so that the rigid tube is within said slot when said fume return hose is compressed to the extent that the outer end of said fume return hose is at said position beyond the housing and said protuberance, whereby said adapter is biased against said protuberance by the outer end of said fume return hose and said valve can be opened by the actuation of said trigger mechanism.

  5. Static performance of a cruciform nozzle with multiaxis thrust-vectoring and reverse-thrust capabilities

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Asbury, Scott C.

    1992-01-01

    A multiaxis thrust vectoring nozzle designed to have equal flow turning capability in pitch and yaw was conceived and experimentally tested for internal, static performance. The cruciform-shaped convergent-divergent nozzle turned the flow for thrust vectoring by deflecting the divergent surfaces of the nozzle, called flaps. Methods for eliminating physical interference between pitch and yaw flaps at the larger multiaxis deflection angles was studied. These methods included restricting the pitch flaps from the path of the yaw flaps and shifting the flow path at the throat off the nozzle centerline to permit larger pitch-flap deflections without interfering with the operation of the yaw flaps. Two flap widths were tested at both dry and afterburning settings. Vertical and reverse thrust configurations at dry power were also tested. Comparison with two dimensional convergent-divergent nozzles showed lower but still competitive thrust performance and thrust vectoring capability.

  6. Experimental thrust performance of a high-area-ratio rocket nozzle

    NASA Technical Reports Server (NTRS)

    Pavli, Albert J.; Kacynski, Kenneth J.; Smith, Tamara A.

    1987-01-01

    An experimental investigation was conducted to determine the thrust performance attainable from high-area-ratio rocket nozzles. A modified Rao-contoured nozzle with an expansion area of 1030 was test fired with hydrogen-oxygen propellants at altitude conditions. The nozzle was also tested as a truncated nozzle, at an expansion area ratio of 428. Thrust coefficient and thrust coefficient efficiency values are presented for each configuration at various propellant mixture ratios (oxygen/fuel). Several procedural techniques were developed permitting improved measurement of nozzle performance. The more significant of these were correcting the thrust for the aneroid effects, determining the effective chamber pressure, and referencing differential pressure transducers to a vacuum reference tank.

  7. Spray nozzles reduce furnace emissions

    SciTech Connect

    Not Available

    1993-10-01

    When the US Environmental Protection Agency (EPA) told an Illinois wood pallet manufacturer to reduce emissions of heavy smoke from its twice-weekly incineration of old pallets, the company didn't find many options. The company applied spray nozzles to enhance the efficiency of the furnaces, and scrub the smoke and gas, removing toxins and particulates before they could reach the furnace chimney and be emitted into the atmosphere. Three types of spray nozzles were installed in the incinerator. Six UniJet air blow-off nozzles, fed by a compressed air line, were installed in the fire box. These nozzles target a flat spray of pressured air to intensify the heat of the fire. As a result, the pallets burn more efficiently and completely. Eight standard FullJet nozzles also were installed in the fire box. Since the smoke concentration is heaviest in this area, the nozzles provide the large drops and the heavy spray distribution needed to clean carbon particulates from the smoke.

  8. Reactor pressure vessel nozzle

    DOEpatents

    Challberg, Roy C.; Upton, Hubert A.

    1994-01-01

    A nozzle for joining a pool of water to a nuclear reactor pressure vessel includes a tubular body having a proximal end joinable to the pressure vessel and a distal end joinable in flow communication with the pool. The body includes a flow passage therethrough having in serial flow communication a first port at the distal end, a throat spaced axially from the first port, a conical channel extending axially from the throat, and a second port at the proximal end which is joinable in flow communication with the pressure vessel. The inner diameter of the flow passage decreases from the first port to the throat and then increases along the conical channel to the second port. In this way, the conical channel acts as a diverging channel or diffuser in the forward flow direction from the first port to the second port for recovering pressure due to the flow restriction provided by the throat. In the backflow direction from the second port to the first port, the conical channel is a converging channel and with the abrupt increase in flow area from the throat to the first port collectively increase resistance to flow therethrough.

  9. Reactor pressure vessel nozzle

    DOEpatents

    Challberg, R.C.; Upton, H.A.

    1994-10-04

    A nozzle for joining a pool of water to a nuclear reactor pressure vessel includes a tubular body having a proximal end joinable to the pressure vessel and a distal end joinable in flow communication with the pool. The body includes a flow passage therethrough having in serial flow communication a first port at the distal end, a throat spaced axially from the first port, a conical channel extending axially from the throat, and a second port at the proximal end which is joinable in flow communication with the pressure vessel. The inner diameter of the flow passage decreases from the first port to the throat and then increases along the conical channel to the second port. In this way, the conical channel acts as a diverging channel or diffuser in the forward flow direction from the first port to the second port for recovering pressure due to the flow restriction provided by the throat. In the backflow direction from the second port to the first port, the conical channel is a converging channel and with the abrupt increase in flow area from the throat to the first port collectively increase resistance to flow therethrough. 2 figs.

  10. Turbulent Flow Field Measurements of Separate Flow Round and Chevron Nozzles with Pylon Interaction Using Particle Image Velocimetry

    NASA Technical Reports Server (NTRS)

    Doty, Michael J.; Henerson, Brenda S.; Kinzie, Kevin W.

    2004-01-01

    Particle Image Velocimetry (PIV) measurements for six separate flow bypass ratio five nozzle configurations have recently been obtained in the NASA Langley Jet Noise Laboratory. The six configurations include a baseline configuration with round core and fan nozzles, an eight-chevron core nozzle at two different clocking positions, and repeats of these configurations with a pylon included. One run condition representative of takeoff was investigated for all cases with the core nozzle pressure ratio set to 1.56 and the total temperature to 828 K. The fan nozzle pressure ratio was set to 1.75 with a total temperature of 350 K, and the freestream Mach number was M = 0.28. The unsteady flow field measurements provided by PIV complement recent computational, acoustic, and mean flow field studies performed at NASA Langley for the same nozzle configurations and run condition. The PIV baseline configuration measurements show good agreement with mean flow field data as well as existing PIV data acquired at NASA Glenn. Nonetheless, the baseline configuration turbulence profile indicates an asymmetric flow field, despite careful attention to concentricity. The presence of the pylon increases the upper shear layer turbulence levels while simultaneously decreasing the turbulence levels in the lower shear layer. In addition, a slightly shorter potential core length is observed with the addition of the pylon. Finally, comparisons of computational results with PIV measurements are favorable for mean flow, slightly over-predicted for Reynolds shear stress, and underpredicted for Reynolds normal stress components.

  11. Cold-flow performance of several variations of a ram-air-cooled plug nozzle for supersonic-cruise aircraft

    NASA Technical Reports Server (NTRS)

    Harrington, D. E.; Nosek, S. M.; Straight, D. M.

    1974-01-01

    Experimental data were obtained with a 21.59 cm (8.5 in.) diameter cold-flow model in a static altitude facility to determine the thrust and pumping characteristics of several variations of a ram-air-cooled plug nozzle. Tests were conducted over a range of nozzle pressure ratios simulating supersonic cruise and takeoff conditions. Primary throat area was also varied to simulate afterburner on and off. Effect of plug size, outer shroud length, primary nozzle geometry, and varying amounts of secondary flow were investigated. At a supersonic cruise pressure ratio of 27, nozzle efficiencies were 99.7 percent for the best configurations.

  12. High Pressure Water Stripping Using Multi-Orifice Nozzles

    NASA Technical Reports Server (NTRS)

    Hoppe, David T.

    1998-01-01

    The use of multi-orifice rotary nozzles not only increases the speed and stripping effectiveness of high pressure water blasting systems, but also greatly increases the complexity of selecting and optimizing the operating parameters. The rotational speed of the nozzle must be coupled with the transverse velocity of the nozzle as it passes across the surface of the substrate being stripped. The radial and angular positions of each orifice must be included in the analysis of the nozzle configuration. Since orifices at the outer edge of the nozzle head move at a faster rate than the orifice located near the center, the energy impact force of the water stream from the outer orifice is spread over a larger area than the water streams from the inner orifice. Utilizing a larger diameter orifice in the outer radial positions increases the energy impact to compensate for its wider force distribution. The total flow rate from the combination of orifices must be monitored and kept below the pump capacity while choosing an orifice to insert in each position. The energy distribution from the orifice pattern is further complicated since the rotary path of all orifices in the nozzle head pass through the center section, contributing to the stripping in this area while only the outer most orifice contributes to the stripping in the shell area at the extreme outside edge of the nozzle. From t he outer most shell to the center section, more orifices contribute to the stripping in each progressively reduced diameter shell. With all these parameters to configure and each parameter change affecting the others, a computer model was developed to track and coordinate these parameters. The computer simulation responds by graphically indicating the cumulative affect from each parameter selected. The results from the proper choices in parameters is a well designed, highly efficient stripping system. A poorly chosen set of parameters will cause the nozzle to strip aggressively in some areas

  13. ADDITIONAL STRESS AND FRACTURE MECHANICS ANALYSES OF PRESSURIZED WATER REACTOR PRESSURE VESSEL NOZZLES

    SciTech Connect

    Walter, Matthew; Yin, Shengjun; Stevens, Gary; Sommerville, Daniel; Palm, Nathan; Heinecke, Carol

    2012-01-01

    In past years, the authors have undertaken various studies of nozzles in both boiling water reactors (BWRs) and pressurized water reactors (PWRs) located in the reactor pressure vessel (RPV) adjacent to the core beltline region. Those studies described stress and fracture mechanics analyses performed to assess various RPV nozzle geometries, which were selected based on their proximity to the core beltline region, i.e., those nozzle configurations that are located close enough to the core region such that they may receive sufficient fluence prior to end-of-life (EOL) to require evaluation of embrittlement as part of the RPV analyses associated with pressure-temperature (P-T) limits. In this paper, additional stress and fracture analyses are summarized that were performed for additional PWR nozzles with the following objectives: To expand the population of PWR nozzle configurations evaluated, which was limited in the previous work to just two nozzles (one inlet and one outlet nozzle). To model and understand differences in stress results obtained for an internal pressure load case using a two-dimensional (2-D) axi-symmetric finite element model (FEM) vs. a three-dimensional (3-D) FEM for these PWR nozzles. In particular, the ovalization (stress concentration) effect of two intersecting cylinders, which is typical of RPV nozzle configurations, was investigated. To investigate the applicability of previously recommended linear elastic fracture mechanics (LEFM) hand solutions for calculating the Mode I stress intensity factor for a postulated nozzle corner crack for pressure loading for these PWR nozzles. These analyses were performed to further expand earlier work completed to support potential revision and refinement of Title 10 to the U.S. Code of Federal Regulations (CFR), Part 50, Appendix G, Fracture Toughness Requirements, and are intended to supplement similar evaluation of nozzles presented at the 2008, 2009, and 2011 Pressure Vessels and Piping (PVP

  14. Comparison of Experimental Data and Computations Fluid Dynamics Analysis for a Three Dimensional Linear Plug Nozzle

    NASA Technical Reports Server (NTRS)

    Ruf, J. H.; Hagemann, G.; Immich, H.

    2003-01-01

    A three dimensional linear plug nozzle of area ratio 12.79 was designed by Astrium. The nozzle was tested within the German National Technology Program LION in a cold air wind tunnel by TU Dresden. The experimental hardware and test conditions are described. Experimental data was obtained for the nozzle without plug side wall fences and then with plug side wall fences. Experimental data for two nozzle pressure ratios (NPR), 116 and 45, are presented for the without fence and with fence configurations. Schlieren images of both NPR were recorded. Axial profiles of plug wall static pressures were measured at several spanwise locations and on the plug base. Detailed computational fluid dynamics (CFD) analysis was performed for these nozzle configurations by NASA MSFC. The CFD exhibits good agreement with the experimental data. A detailed comparison of the CFD results and the experimental plug wall pressure data is given for four test conditions; at both NPRs, without and with plug side wall fences. Numerical schlieren images are compared to experimental schlieren images. Nozzle thrust efficiencies are calculated from the CFD results. The CFD results are used to illustrate the plug nozzle fluid dynamics for all four test conditions. The effect of the plug side wall fences at both NPRs is emphasized.

  15. Comparison of Experimental Data and Computations Fluid Dynamics Analysis for a Three Dimensional Linear Plug Nozzle

    NASA Technical Reports Server (NTRS)

    Ruf, J. H.; Hagemann, G.; Immich, H.

    2003-01-01

    A three dimensional linear plug nozzle of area ratio 12.79 was designed by EADS Space Transportation (former Astrium Space Infrastructure). The nozzle was tested within the German National Technology Program 'LION' in a cold air wind tunnel by TU Dresden. The experimental hardware and test conditions are described. Experimental data was obtained for the nozzle without plug side wall fences at a nozzle pressure ratio of 116 and then with plug side wall fences at NPR 110. Schlieren images were recorded and axial profiles of plug wall static pressures were measured at several spanwise locations and on the plug base. Detailed CFD analysis was performed for these nozzle configurations at NPR 116 by NASA MSFC. The CFD exhibits good agreement with the experimental data. A detailed comparison of the CFD results and the experimental plug wall pressure data are given. Comparisons are made for both the without and with plug side wall fence configurations. Numerical results for density gradient are compared to experimental Schlieren images. Experimental nozzle thrust efficiencies are calculated based on the CFD results. The CFD results are used to illustrate the plug nozzle fluid dynamics. The effect of the plug side wall is emphasized.

  16. An Experimental and Computational Investigation of a Translating Throat Single Expansion-Ramp Nozzle

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.; Asbury, Scott C.

    1996-01-01

    A translating throat single expansion-ramp nozzle (SERN) concept was designed to improve the off-design performance of a SERN with a large, fixed expansion ratio. The concept of translating the nozzle throat provides the SERN with a variable expansion ratio. An experimental and computational study was conducted to predict and verify the internal performance of this concept. Three nozzles with expansion ratios designed for low, intermediate, and high Mach number operating conditions were tested in the Jet-Exit Test Facility at the NASA Langley Research Center. Each nozzle was tested with a concave and a convex geometric expansion ramp surface design. Internal nozzle performance, paint-oil flow and focusing Schlieren flow visualization were obtained for nozzle pressure ratios (NPR's) up to 13. The Navier-Stokes code, PAB3D, with a k-epsilon turbulence model was utilized to verify experimental results at selected NPR's and to predict the performance at conditions unattainable in the test facility. Two-dimensional simulations were computed with near static free-stream conditions and at nozzle pressure ratios of 5, 9, and 13 for the concave ramp, low Mach number configuration and at the design NPR of 102 for the concave ramp, high Mach number configuration. Remarkable similarities between predicted and experimental flow characteristics, as well as performance quantities, were obtained.

  17. An experimental and computational investigation of a translating throat single expansion-ramp nozzle

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.; Asbury, Scott C.

    1996-01-01

    A translating throat single expansion-ramp nozzle (SERN) concept was designed to improve the off-design performance of a SERN with a large, fixed expansion ratio. The concept of translating the nozzle throat provides the SERN with a variable expansion ratio. An experimental and computational study was conducted to predict and verify the internal performance of this concept. Three nozzles with expansion ratios designed for low, intermediate, and high Mach number operating conditions were tested in the Jet-Exit Test Facility at the NASA Langley Research Center. Each nozzle was tested with a concave and a convex geometric expansion ramp surface design. Internal nozzle performance, paint-oil flow and focusing Schlieren flow visualization were obtained for nozzle pressure ratios (NPR's) up to 13. The Navier-Stokes code, PAB3D, with a k-epsilon turbulence model was utilized to verify experimental results at selected NPRs and to predict the performance at conditions unattainable in the test facility. Two-dimensional simulations were computed with near static free-stream conditions and at nozzle pressure ratios of 5, 9, and 13 for the concave ramp, low Mach number configuration and at the design NPR of 102 for the concave ramp, high Mach number configuration. Remarkable similarities between predicted and experimental flow characteristics, as well as performance quantities, were obtained.

  18. Static internal performance of single-expansion-ramp nozzles with various combinations of internal geometric parameters

    NASA Technical Reports Server (NTRS)

    Re, R. J.; Leavitt, L. D.

    1984-01-01

    The effects of five geometric design parameters on the internal performance of single-expansion-ramp nozzles were investigated at nozzle pressure ratios up to 10 in the static-test facility of the Langley 16-Foot Transonic Tunnel. The geometric variables on the expansion-ramp surface of the upper flap consisted of ramp chordal angle, ramp length, and initial ramp angle. On the lower flap, the geometric variables consisted of flap angle and flap length. Both internal performance and static-pressure distributions on the centerlines of the upper and lower flaps were obtained for all 43 nozzle configurations tested.

  19. Static Performance of a Fixed-Geometry Exhaust Nozzle Incorporating Porous Cavities for Shock-Boundary Layer Interaction Control

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.; Hunter, Craig A.

    1999-01-01

    An investigation was conducted in the model preparation area of the Langley 16-Foot Transonic Tunnel to determine the internal performance of a fixed-geometry exhaust nozzle incorporating porous cavities for shock-boundary layer interaction control. Testing was conducted at static conditions using a sub-scale nozzle model with one baseline and 27 porous configurations. For the porous configurations, the effects of percent open porosity, hole diameter, and cavity depth were determined. All tests were conducted with no external flow at nozzle pressure ratios from 1.25 to approximately 9.50. Results indicate that baseline nozzle performance was dominated by unstable, shock-induced, boundary-layer separation at over-expanded conditions. Porous configurations were capable of controlling off-design separation in the nozzle by either alleviating separation or encouraging stable separation of the exhaust flow. The ability of the porous nozzle concept to alternately alleviate separation or encourage stable separation of exhaust flow through shock-boundary layer interaction control offers tremendous off-design performance benefits for fixed-geometry nozzle installations. In addition, the ability to encourage separation on one divergent flap while alleviating it on the other makes it possible to generate thrust vectoring using a fixed-geometry nozzle.

  20. Free jet feasibility study of a thermal acoustic shield concept for AST/VCE application: Single stream nozzles

    NASA Technical Reports Server (NTRS)

    Majjigi, R. K.; Brausch, J. F.; Janardan, B. A.; Balsa, T. F.; Knott, P. R.; Pickup, N.

    1984-01-01

    A technology base for the thermal acoustic shield concept as a noise suppression device for single stream exhaust nozzles was developed. Acoustic data for 314 test points for 9 scale model nozzle configurations were obtained. Five of these configurations employed an unsuppressed annular plug core jet and the remaining four nozzles employed a 32 chute suppressor core nozzle. Influence of simulated flight and selected geometric and aerodynamic flow variables on the acoustic behavior of the thermal acoustic shield was determined. Laser velocimeter and aerodynamic measurements were employed to yield valuable diagnostic information regarding the flow field characteristics of these nozzles. An existing theoretical aeroacoustic prediction method was modified to predict the acoustic characteristics of partial thermal acoustic shields.

  1. Noise Prediction Module for Offset Stream Nozzles

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda S.

    2011-01-01

    A Modern Design of Experiments (MDOE) analysis of data acquired for an offset stream technology was presented. The data acquisition and concept development were funded under a Supersonics NRA NNX07AC62A awarded to Dimitri Papamoschou at University of California, Irvine. The technology involved the introduction of airfoils in the fan stream of a bypass ratio (BPR) two nozzle system operated at transonic exhaust speeds. The vanes deflected the fan stream relative to the core stream and resulted in reduced sideline noise for polar angles in the peak jet noise direction. Noise prediction models were developed for a range of vane configurations. The models interface with an existing ANOPP module and can be used or future system level studies.

  2. Acoustics and Trust of Separate-Flow Exhaust Nozzles With Mixing Devices for High-Bypass-Ratio Engines

    NASA Technical Reports Server (NTRS)

    Saiyed, Naseem H.; Mikkelsen, Kevin L.; Bridges, James E.

    2000-01-01

    The NASA Glenn Research Center recently completed an experimental study to reduce the jet noise from modern turbofan engines. The study concentrated on exhaust nozzle designs for high-bypass-ratio engines. These designs modified the core and fan nozzles individually and simultaneously. Several designs provided an ideal jet noise reduction of over 2.5 EPNdB for the effective perceived noise level (EPNL) metric. Noise data, after correcting for takeoff thrust losses, indicated over a 2.0-EPNdB reduction for nine designs. Individually modifying the fan nozzle did not provide attractive EPNL reductions. Designs in which only the core nozzle was modified provided greater EPNL reductions. Designs in which core and fan nozzles were modified simultaneously provided the greatest EPNL reduction. The best nozzle design had a 2.7-EPNdB reduction (corrected for takeoff thrust loss) with a 0.06-point cruise thrust loss. This design simultaneously employed chevrons on the core and fan nozzles. In comparison with chevrons, tabs appeared to be an inefficient method for reducing jet noise. Data trends indicate that the sum of the thrust losses from individually modifying core and fan nozzles did not generally equal the thrust loss from modifying them simultaneously. Flow blockage from tabs did not scale directly with cruise thrust loss and the interaction between fan flow and the core nozzle seemed to strongly affect noise and cruise performance. Finally, the nozzle configuration candidates for full-scale engine demonstrations are identified.

  3. Static internal performance of a thrust vectoring and reversing two-dimensional convergent-divergent nozzle with an aft flap

    NASA Technical Reports Server (NTRS)

    Re, R. J.; Leavitt, L. D.

    1986-01-01

    The static internal performance of a multifunction nozzle having some of the geometric characteristics of both two-dimensional convergent-divergent and single expansion ramp nozzles has been investigated in the static-test facility of the Langley 16-Foot Transonic Tunnel. The internal expansion portion of the nozzle consisted of two symmetrical flat surfaces of equal length, and the external expansion portion of the nozzle consisted of a single aft flap. The aft flap could be varied in angle independently of the upper internal expansion surface to which it was attached. The effects of internal expansion ratio, nozzle thrust-vector angle (-30 deg. to 30 deg., aft flap shape, aft flap angle, and sidewall containment were determined for dry and afterburning power settings. In addition, a partial afterburning power setting nozzle, a fully deployed thrust reverser, and four vertical takeoff or landing nozzle, configurations were investigated. Nozzle pressure ratio was varied up to 10 for the dry power nozzles and 7 for the afterburning power nozzles.

  4. Numerical Optimization of converging diverging miniature cavitating nozzles

    NASA Astrophysics Data System (ADS)

    Chavan, Kanchan; Bhingole, B.; Raut, J.; Pandit, A. B.

    2015-12-01

    The work focuses on the numerical optimization of converging diverging cavitating nozzles through nozzle dimensions and wall shape. The objective is to develop design rules for the geometry of cavitating nozzles for desired end-use. Two main aspects of nozzle design which affects the cavitation have been studied i.e. end dimensions of the geometry (i.e. angle and/or curvature of the inlet, outlet and the throat and the lengths of the converging and diverging sections) and wall curvatures(concave or convex). Angle of convergence at the inlet was found to control the cavity growth whereas angle of divergence of the exit controls the collapse of cavity. CFD simulations were carried out for the straight line converging and diverging sections by varying converging and diverging angles to study its effect on the collapse pressure generated by the cavity. Optimized geometry configurations were obtained on the basis of maximum Cavitational Efficacy Ratio (CER)i.e. cavity collapse pressure generated for a given permanent pressure drop across the system. With increasing capabilities in machining and fabrication, it is possible to exploit the effect of wall curvature to create nozzles with further increase in the CER. Effect of wall curvature has been studied for the straight, concave and convex shapes. Curvature has been varied and effect of concave and convex wall curvatures vis-à-vis straight walls studied for fixed converging and diverging angles.It is concluded that concave converging-diverging nozzles with converging angle of 20° and diverging angle of 5° with the radius of curvature 0.03 m and 0.1530 m respectively gives maximum CER. Preliminary experiments using optimized geometry are indicating similar trends and are currently being carried out. Refinements of the CFD technique using two phase flow simulations are planned.

  5. Experimental investigation of shock-cell noise reduction for dual-stream nozzles in simulated flight comprehensive data report. Volume 1: Test nozzles and acoustic data

    NASA Technical Reports Server (NTRS)

    Yamamoto, K.; Janardan, B. A.; Brausch, J. F.; Hoerst, D. J.; Price, A. O.

    1984-01-01

    Parameters which contribute to supersonic jet shock noise were investigated for the purpose of determining means to reduce such noise generation to acceptable levels. Six dual-stream test nozzles with varying flow passage and plug closure designs were evaluated under simulated flight conditions in an anechoic chamber. All nozzles had combined convergent-divergent or convergent flow passages. Acoustic behavior as a function of nozzle flow passage geometry was measured. The acoustic data consist primarily of 1/3 octave band sound pressure levels and overall sound pressure levels. Detailed schematics and geometric characteristics of the six scale model nozzle configurations and acoustic test point definitions are presented. Tabulation of aerodynamic test conditions and a computer listing of the measured acoustic data are displayed.

  6. Nozzle geometry for organic vapor jet printing

    DOEpatents

    Forrest, Stephen R; McGraw, Gregory

    2015-01-13

    A first device is provided. The device includes a print head. The print head further includes a first nozzle hermetically sealed to a first source of gas. The first nozzle has an aperture having a smallest dimension of 0.5 to 500 microns in a direction perpendicular to a flow direction of the first nozzle. At a distance from the aperture into the first nozzle that is 5 times the smallest dimension of the aperture of the first nozzle, the smallest dimension perpendicular to the flow direction is at least twice the smallest dimension of the aperture of the first nozzle.

  7. Experimental and Computational Investigation of Multiple Injection Ports in a Convergent-Divergent Nozzle for Fluidic Thrust Vectoring

    NASA Technical Reports Server (NTRS)

    Waithe, Kenrick A.; Deere, Karen A.

    2003-01-01

    A computational and experimental study was conducted to investigate the effects of multiple injection ports in a two-dimensional, convergent-divergent nozzle, for fluidic thrust vectoring. The concept of multiple injection ports was conceived to enhance the thrust vectoring capability of a convergent-divergent nozzle over that of a single injection port without increasing the secondary mass flow rate requirements. The experimental study was conducted at static conditions in the Jet Exit Test Facility of the 16-Foot Transonic Tunnel Complex at NASA Langley Research Center. Internal nozzle performance was obtained at nozzle pressure ratios up to 10 with secondary nozzle pressure ratios up to 1 for five configurations. The computational study was conducted using the Reynolds Averaged Navier-Stokes computational fluid dynamics code PAB3D with two-equation turbulence closure and linear Reynolds stress modeling. Internal nozzle performance was predicted for nozzle pressure ratios up to 10 with a secondary nozzle pressure ratio of 0.7 for two configurations. Results from the experimental study indicate a benefit to multiple injection ports in a convergent-divergent nozzle. In general, increasing the number of injection ports from one to two increased the pitch thrust vectoring capability without any thrust performance penalties at nozzle pressure ratios less than 4 with high secondary pressure ratios. Results from the computational study are in excellent agreement with experimental results and validates PAB3D as a tool for predicting internal nozzle performance of a two dimensional, convergent-divergent nozzle with multiple injection ports.

  8. Static internal performance of convergent single-expansion-ramp nozzles with various combinations of internal geometric parameters

    NASA Technical Reports Server (NTRS)

    Bare, E. Ann; Capone, Francis J.

    1989-01-01

    An investigation was conducted in the Static Test Facility of the Langley 16-Foot Transonic Tunnel to determine the effects of five geometric design parameters on the internal performance of convergent single expansion ramp nozzles. The effects of ramp chordal angle, initial ramp angle, flap angle, flap length, and ramp length were determined. All nozzles tested has a nominally constant throat area and aspect ratio. Static pressure distributions along the centerlines of the ramp and flap were also obtained for each configuration. Nozzle pressure ratio was varied up to 10.0 for all configurations.

  9. Two-dimensional converging-diverging rippled nozzles at transonic speeds. [performed in the Langley 16-Foot Transonic Tunnel

    NASA Technical Reports Server (NTRS)

    Carlson, John R.; Asbury, Scott C.

    1994-01-01

    An experimental investigation was performed in the Langley 16-Foot Transonic tunnel to determine the effects of external and internal flap rippling on the aerodynamics of a nonaxisymmetric nozzle. Data were obtained at several Mach numbers from static conditions to 1.2 over a range of nozzle pressure ratios. Nozzles with chordal boattail angles of 10, 20, and 30 degrees, with and without surface rippling, were tested. No effect on discharge coefficient due to surface rippling was observed. Internal thrust losses due to surface rippling were measured and attributed to a combination of additional internal skin friction and shock losses. External nozzle drag for the baseline configurations were generally less than that for the rippled configurations at all free-stream Mach numbers tested. The difference between the baseline and rippled nozzle drag levels generally increased with increasing boat tail angle. The thrust-minus-drag level for each rippled nozzle configuration was less than the equivalent baseline configuration for each Mach number at the design nozzle pressure ratio.

  10. Acoustic and aerodynamic performance investigation of inverted velocity profile coannular plug nozzles. [variable cycle engines

    NASA Technical Reports Server (NTRS)

    Knott, P. R.; Blozy, J. T.; Staid, P. S.

    1981-01-01

    The results of model scale parametric static and wind tunnel aerodynamic performance tests on unsuppressed coannular plug nozzle configurations with inverted velocity profile are discussed. The nozzle configurations are high-radius-ratio coannular plug nozzles applicable to dual-stream exhaust systems typical of a variable cycle engine for Advanced Supersonic Transport application. In all, seven acoustic models and eight aerodynamic performance models were tested. The nozzle geometric variables included outer stream radius ratio, inner stream to outer stream ratio, and inner stream plug shape. When compared to a conical nozzle at the same specific thrust, the results of the static acoustic tests with the coannular nozzles showed noise reductions of up to 7 PNdB. Extensive data analysis showed that the overall acoustic results can be well correlated using the mixed stream velocity and the mixed stream density. Results also showed that suppression levels are geometry and flow regulation dependent with the outer stream radius ratio, inner stream-to-outer stream velocity ratio and inner stream velocity ratio and inner stream plug shape, as the primary suppression parameters. In addition, high-radius ratio coannular plug nozzles were found to yield shock associated noise level reductions relative to a conical nozzle. The wind tunnel aerodynamic tests showed that static and simulated flight thrust coefficient at typical takeoff conditions are quite good - up to 0.98 at static conditions and 0.974 at a takeoff Mach number of 0.36. At low inner stream flow conditions significant thrust loss was observed. Using an inner stream conical plug resulted in 1% to 2% higher performance levels than nozzle geometries using a bent inner plug.

  11. Flight effects on the aerodynamic and acoustic characteristics of inverted profile coannular nozzles, volume 1. [supersonic cruise aircraft research wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.

    1978-01-01

    Jet noise spectra obtained at static conditions from an acoustic wind tunnel and an outdoor facility are compared. Data curves are presented for (1) the effect of relative velocity on OASPL directivity (all configurations); (2) the effect of relative velocity on noise spectra (all configurations); (3) the effect of velocity on PNL directivity (coannular nozzle configurations); (4) nozzle exhaust plume velocity profiles; and (5) the effect of relative velocity on aerodynamic performance.

  12. Development of Air Speed Nozzles

    NASA Technical Reports Server (NTRS)

    Zahm, A F

    1920-01-01

    Report describes the development of a suitable speed nozzle for the first few thousand airplanes made by the United States during the recent war in Europe, and to furnish a basis for more mature instruments in the future. Requirements for the project were to provide a suitable pressure collector for aircraft speed meters and to develop a speed nozzle which would be waterproof, powerful, unaffected by slight pitch and yaw, rugged and easy to manufacture, and uniform in structure and reading, so as not to require individual calibration.

  13. Nozzle for superconducting fiber production

    DOEpatents

    Righi, Jamal

    1992-11-17

    A nozzle apparatus for producing flexible fibers of superconducting material receives melted material from a crucible for containing a charge of the superconducting material. The material is melted in the crucible and falls in a stream through a bottom hole in the crucible. The stream falls through a protecting collar which maintains the stream at high temperatures. The stream is then supplied through the downwardly directed nozzle where it is subjected to a high velocity air flow which breaks the melted superconducting material into ligaments which solidify into the flexible fibers. The fibers are collected by blowing them against a porous cloth.

  14. High Pressure Water Stripping Using Multi-Orifice Nozzles

    NASA Technical Reports Server (NTRS)

    Hoppe, David

    1999-01-01

    The use of multi-orifice rotary nozzles greatly increases the speed and stripping effectiveness of high pressure water blasting systems, but also greatly increases the complexity of selecting and optimizing the operating parameters. The rotational speed of the nozzle must be coupled with its transverse velocity as it passes across the surface of the substrate being stripped. The radial and angular positions of each orifice must be included in the analysis of the nozzle configuration. Orifices at the outer edge of the nozzle head move at a faster rate than the orifices located near the center. The energy transmitted to the surface from the impact force of the water stream from an outer orifice is therefore spread over a larger area than energy from an inner orifice. Utilizing a larger diameter orifice in the outer radial positions increases the total energy transmitted from the outer orifice to compensate for the wider distribution of energy. The total flow rate from the combination of all orifices must be monitored and should be kept below the pump capacity while choosing orifice to insert in each position. The energy distribution from the orifice pattern is further complicated since the rotary path of all the orifices in the nozzle head pass through the center section. All orifices contribute to the stripping in the center of the path while only the outer most orifice contributes to the stripping at the edge of the nozzle. Additional orifices contribute to the stripping from the outer edge toward the center section. With all these parameters to configure and each parameter change affecting the others, a computer model was developed to track and coordinate these parameters. The computer simulation graphically indicates the cumulative affect from each parameter selected. The result from the proper choices in parameters is a well designed, highly efficient stripping system. A poorly chosen set of parameters will cause the nozzle to strip aggressively in some areas

  15. Exploratory studies of the cruise performance of upper surface blown configuration: Experimental program, high-speed force tests

    NASA Technical Reports Server (NTRS)

    Braden, J. A.; Hancock, J. P.; Burdges, K. P.; Hackett, J. E.

    1979-01-01

    The work to develop a wing-nacelle arrangement to accommodate a wide range of upper surface blown configuration is reported. Pertinent model and installation details are described. Data of the effects of a wide range of nozzle geometric variations are presented. Nozzle aspect ratio, boattail angle, and chordwise position are among the parameters investigated. Straight and swept wing configurations were tested across a range of nozzle pressure ratios, lift coefficients, and Mach numbers.

  16. Design of supersonic Coanda jet nozzles

    NASA Technical Reports Server (NTRS)

    Bevilaqua, Paul M.; Lee, John D.

    1987-01-01

    The thrust vectoring of supersonic Coanda jets was improved by designing a nozzle to skew the initial jet velocity profile. A new nozzle design procedure, based on the method of characteristics, was developed to design a nozzle which produces a specified exit velocity profile. The thrust vectoring of a simple convergent nozzle, a convergent-divergent nozzle, and a nozzle which produces a skewed velocity profile matched to the curvature of the Coanda surface were expermentially compared over a range of pressure ratios from 1.5 to 3.5. Elimination of the expansion shocks with the C-D nozzle is shown to greatly improve the thrust vectoring; elimination of turning shocks with the skewed profile nozzle further improves the vectoring.

  17. Multielement suppressor nozzles for thrust augmentation systems.

    NASA Technical Reports Server (NTRS)

    Lawrence, R. L.; O'Keefe, J. V.; Tate, R. B.

    1972-01-01

    The noise reduction and nozzle performance characteristics of large-scale, high-aspect-ratio multielement nozzle arrays operated at low velocities were determined by test. The nozzles are selected for application to high-aspect-ratio augmentor suppressors to be used for augmentor wing airplanes. Significant improvements in noise characteristics for multielement nozzles over those of round or high-aspect-ratio slot nozzles are obtained. Elliptical noise patterns typical of slot nozzles are presented for high-aspect-ratio multielement nozzle arrays. Additional advantages are available in OASPL noise reduction from the element size and spacing. Augmentor-suppressor systems can be designed for maximum beam pattern directivity and frequency spectrum shaping advantages. Measurements of the nozzle wakes show a correlation with noise level data and frequency spectrum peaks. The noise and jet wake results are compared with existing prediction procedures based on empirical jet flow equations, Lighthill relationships, Strouhal number, and empirical shock-induced screech noise effects.

  18. 46 CFR 154.1120 - Nozzles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Nozzles. (a) Nozzles for the water spray system must be spaced to provide the minimum discharge density under § 154.1115 in each part of the protected area. (b) The vertical distance between water...

  19. 46 CFR 154.1120 - Nozzles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Nozzles. (a) Nozzles for the water spray system must be spaced to provide the minimum discharge density under § 154.1115 in each part of the protected area. (b) The vertical distance between water...

  20. 46 CFR 154.1120 - Nozzles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Nozzles. (a) Nozzles for the water spray system must be spaced to provide the minimum discharge density under § 154.1115 in each part of the protected area. (b) The vertical distance between water...

  1. Plasma Detachment Studies in the VASIMR Magnetic Nozzle

    NASA Astrophysics Data System (ADS)

    Tarditi, Alfonso G.; Shebalin, John

    2004-11-01

    Two important issues related to the VASIMR (Variable Specific Impulse Magnetoplasma Rocket, [1]) experiment are the plasma detachment and the collimation of the plume in the magnetic nozzle. These issues are being investigated both through theory/simulation studies and now also experimentally. A 3D, nonlinear MHD/2-fluid model of the magnetic nozzle has been implemented with the NIMROD code. The model has been run both with the actual VASIMR geometry and for an ideal De Laval nozzle configuration. The simulations indicate a distortion of the external field due to the plasma exhaust flow (carrying an azimuthal diamagnetic current) that may to lead to plasma detachment through the formation of magnetic islands. This is also being investigated experimentally. A Hall-effect, one-axis, gaussmeter has shown the local low-frequency magnetic field fluctuations during a plasma pulse. A 2D array of 3-axis "B-dot" probes is being developed for a fast mapping of the field perturbations in the nozzle (on the order of the Alfven time). Finally, a Rogowski coil probe is being designed to measure the azimuthal current profile in the exhaust plasma. [1] F. R. Chang-Diaz et al, Scientific American, p. 90, Nov. 2000

  2. Computer aided design study of hypermixing nozzles

    NASA Technical Reports Server (NTRS)

    Mefferd, L. A.; Bevilacqua, P. M.

    1979-01-01

    The development of a nozzle which combines the hypermixing and lobe mechanisms to achieve further increases in jet entrainment and ejector performance is investigated. A computer program which incorporates a two equation turbulence model and is used to predict and compare the evolution of jets from various nozzle designs is discussed. Increasing the length of the nozzle lobes and an alternating lobe nozzle are a methods examined for increasing the entrainment rate.

  3. Nozzle Extension for Safety Air Gun

    NASA Technical Reports Server (NTRS)

    Zumbrun, H. N.; Croom, Delwin R., Jr.

    1986-01-01

    New nozzle-extension design overcomes problems and incorporates original commercial nozzle, retaining intrinsic safety features. Components include extension tube, length of which made to suit application; adaptor fitting, and nozzle adaptor repinned to maintain original safety features. Design moves conical airstream to end of extension to blow machine chips away from operator. Nozzle-extension modification allows safe and efficient operation of machine tools while maintaining integrity of orginial safety-air-gun design.

  4. Cooled variable nozzle radial turbine for rotor craft applications

    NASA Technical Reports Server (NTRS)

    Rogo, C.

    1981-01-01

    An advanced, small 2.27 kb/sec (5 lbs/sec), high temperature, variable area radial turbine was studied for a rotor craft application. Variable capacity cycles including single-shaft and free-turbine engine configurations were analyzed to define an optimum engine design configuration. Parametric optimizations were made on cooled and uncooled rotor configurations. A detailed structural and heat transfer analysis was conducted to provide a 4000-hour life HP turbine with material properties of the 1988 time frame. A pivoted vane and a moveable sidewall geometry were analyzed. Cooling and variable geometry penalties were included in the cycle analysis. A variable geometry free-turbine engine configuration with a design 1477K (2200 F) inlet temperature and a compressor pressure ratio of 16:1 was selected. An uncooled HP radial turbine rotor with a moveable sidewall nozzle showed the highest performance potential for a time weighted duty cycle.

  5. Kinetic energy of rainfall simulation nozzles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Different spray nozzles are used frequently to simulate natural rain for soil erosion and chemical transport, particularly phosphorous (P), studies. Oscillating VeeJet nozzles are used mostly in soil erosion research while constant spray FullJet nozzles are commonly used for P transport. Several ch...

  6. Reactor pressure vessel with forged nozzles

    DOEpatents

    Desai, Dilip R.

    1993-01-01

    Inlet nozzles for a gravity-driven cooling system (GDCS) are forged with a cylindrical reactor pressure vessel (RPV) section to which a support skirt for the RPV is attached. The forging provides enhanced RPV integrity around the nozzle and substantial reduction of in-service inspection costs by eliminating GDCS nozzle-to-RPV welds.

  7. Nozzles for size reclassification of microfog particles

    NASA Technical Reports Server (NTRS)

    Leonardi, S. J.; Shim, J.

    1969-01-01

    Modified reclassifying nozzles, commonly used with mist lubrication systems, creates larger particle sizes in the mist. The concept used involves the wetting out of particles within the nozzle with continuous reatomization of the resulting liquid film by passing gas through the nozzle.

  8. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, W.G.; Harris, M.T.; Scott, T.C.; Basaran, O.A.

    1996-04-02

    A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 5 figs.

  9. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, W.G.; Basaran, O.A.; Harris, M.T.

    1995-11-07

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 4 figs.

  10. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, Warren G.; Basaran, Osman A.; Harris, Michael T.

    1995-01-01

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

  11. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, Warren G.; Harris, Michael T.; Scott, Timothy C.; Basaran, Osman A.

    1996-01-01

    A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

  12. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, Warren G.; Basaran, Osman A.; Harris, Michael T.

    1998-01-01

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

  13. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, Warren G.; Harris, Michael T.; Scott, Timothy C.; Basaran, Osman A.

    1998-01-01

    A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode.

  14. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, W.G.; Basaran, O.A.; Harris, M.T.

    1998-04-14

    A nozzle for an electric dispersion reactor includes two concentric electrodes, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 4 figs.

  15. Nozzle for electric dispersion reactor

    DOEpatents

    Sisson, W.G.; Harris, M.T.; Scott, T.C.; Basaran, O.A.

    1998-06-02

    A nozzle for an electric dispersion reactor includes two coaxial cylindrical bodies, the inner one of the two delivering disperse phase fluid into a continuous phase fluid. A potential difference generated by a voltage source creates a dispersing electric field at the end of the inner electrode. 5 figs.

  16. Combustion Dynamics in Multi-Nozzle Combustors Operating on High-Hydrogen Fuels

    SciTech Connect

    Santavicca, Dom; Lieuwen, Tim

    2013-09-30

    Actual gas turbine combustors for power generation applications employ multi-nozzle combustor configurations. Researchers at Penn State and Georgia Tech have extended previous work on the flame response in single-nozzle combustors to the more realistic case of multi-nozzle combustors. Research at Georgia Tech has shown that asymmetry of both the flow field and the acoustic forcing can have a significant effect on flame response and that such behavior is important in multi-flame configurations. As a result, the structure of the flame and its response to forcing is three-dimensional. Research at Penn State has led to the development of a three-dimensional chemiluminescence flame imaging technique that can be used to characterize the unforced (steady) and forced (unsteady) flame structure of multi-nozzle combustors. Important aspects of the flame response in multi-nozzle combustors which are being studied include flame-flame and flame-wall interactions. Research at Penn State using the recently developed three-dimensional flame imaging technique has shown that spatial variations in local flame confinement must be accounted for to accurately predict global flame response in a multi-nozzle can combustor.

  17. Distributed Exhaust Nozzles for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Ahuja, K. K.; Gaeta, R. J.; Hellman, B.; Schein, D. B.; Solomon, W. D., Jr.; Huff, Dennis (Technical Monitor)

    2001-01-01

    The main objective of this study is to validate the jet noise reduction potential of a concept associated with distributed exhaust nozzles. Under this concept the propulsive thrust is generated by a larger number of discrete plumes issuing from an array of small or mini-nozzles. The potential of noise reduction of this concept stems from the fact that a large number of small jets will produce very high frequency noise and also, if spaced suitably, they will coalesce at a smaller velocity to produce low amplitude, low frequency noise. This is accomplished through detailed acoustic and fluid measurements along with a Computational Fluidic Dynamic (CFD) solution of the mean (DE) Distributed Exhaust nozzle flowfield performed by Northrop-Grumman. The acoustic performance is quantified in an anechoic chamber. Farfield acoustic data is acquired for a DE nozzle as well as a round nozzle of the same area. Both these types of nozzles are assessed numerically using Computational Fluid Dynamic (CFD) techniques. The CFD analysis ensures that both nozzles issued the same amount of airflow for a given nozzle pressure ratio. Data at a variety of nozzle pressure ratios are acquired at a range of polar and azimuthal angles. Flow visualization of the DE nozzle is used to assess the fluid dynamics of the small jet interactions. Results show that at high subsonic jet velocities, the DE nozzle shifts its frequency of peak amplitude to a higher frequency relative to a round nozzle of equivalent area (from a S(sub tD) = 0.24 to 1. 3). Furthermore, the DE nozzle shows reduced sound pressure levels (as much as 4 - 8 dB) in the low frequency part of the spectrum (less than S(sub tD) = 0.24 ) compared to the round nozzle. At supersonic jet velocities, the DE nozzle does not exhibit the jet screech and the shock-associated broadband noise is reduced by as much as 12 dB.

  18. Flap noise and aerodynamic results for model QCSEE over-the-wing configurations

    NASA Technical Reports Server (NTRS)

    Olsen, W.; Burns, R.; Groesbeck, D. E.

    1977-01-01

    Noise spectra in three dimensions and aerodynamic data were measured for a model of the NASA quiet clean short-haul experimental engine (QCSEE) over-the-wing configuration. The effects of flap length, nozzle exhaust velocity, and nozzle geometry were determined using a single nozzle and wing-flap segment. The scaled-up model data is representative of full scale flap noise with the QCSEE engine.

  19. Numerical Investigation of Flow in an Over-Expanded Nozzle with Porous Surfaces

    NASA Technical Reports Server (NTRS)

    Elmiligui, Alaa; Abdol-Hamid, K. S.; Hunter, Craig A.

    2005-01-01

    A new porous condition has been implemented in the PAB3D solver for simulating the flow over porous surfaces. The newly-added boundary condition is utilized to compute the flow field of a non-axisymmetric, convergent-divergent nozzle incorporating porous cavities for shock-boundary layer interaction control. The nozzle has an expansion ratio (exit area/throat area) of 1.797 and a design nozzle pressure ratio of 8.78. The flow fields for a baseline nozzle (no porosity) and for a nozzle with porous surfaces (10% porosity ratio) are computed for NPR varying from 2.01 to 9.54. Computational model results indicate that the over-expanded nozzle flow was dominated by shock-induced boundary-layer separation. Porous configurations were capable of controlling off-design separation in the nozzle by encouraging stable separation of the exhaust flow. Computational simulation results, wall centerline pressure, mach contours, and thrust efficiency ratio are presented and discussed. Computed results are in excellent agreement with experimental data.

  20. Numerical Investigation of Flow in an Over-expanded Nozzle with Porous Surfaces

    NASA Technical Reports Server (NTRS)

    Abdol-Hamid, Khaled S.; Elmilingui, Alaa A.; Hunter, Craig A.

    2006-01-01

    A new porous condition has been implemented in the PAB3D solver for simulating the flow over porous surfaces. The newly-added boundary condition is utilized to compute the flow field of a non-axisymmetric, convergent-divergent nozzle incorporating porous cavities for shock-boundary layer interaction control. The nozzle has an expansion ratio (exit area/throat area) of 1.797 and a design nozzle pressure ratio of 8.78. The flow fields for a baseline nozzle (no porosity) and for a nozzle with porous surfaces (10% porosity ratio) are computed for NPR varying from 2.01 to 9.54. Computational model results indicate that the over-expanded nozzle flow is dominated by shock-induced boundary-layer separation. Porous configurations are capable of controlling off-design separation in the nozzle by encouraging stable separation of the exhaust flow. Computational simulation results, wall centerline pressure, mach contours, and thrust efficiency ratio are presented and discussed. Computed results are in excellent agreement with experimental data.

  1. Assessment at full scale of exhaust nozzle-to-wing size on STOL-OTW acoustic characteristics

    NASA Technical Reports Server (NTRS)

    Von Glahn, U.; Groesbeck, D.

    1979-01-01

    On the basis of static zero/acoustic data obtained at model scale, the effect of exhaust nozzle size on flyover noise is evaluated at full scale for different STOL-OTW nozzle configurations. Three types of nozzles are evaluated: a circular/deflector nozzle mounted above the wing, a slot/deflector nozzle mounted on the wing, and a slot nozzle mounted on the wing. The nozzle exhaust plane location, measured from the wing leading edge was varied from 10 to 46 percent of the wing chord (flaps retracted). Flap angles of 20 deg (takeoff) and 60 deg (approach) are included in the study. Initially, perceived noise levels (PNL) are calculated as a function of flyover distance at 152 m altitude. From these plots static EPNL values, defined as flyover relative noise levels, then are obtained as functions of nozzle size for equal aerodynamic performance (lift and thrust). On the basis of these calculations, the acoustic benefits attributable to nozzle size relative to a given wing chord size are assessed.

  2. Two-phase flow research. Phase 1: Two-phase nozzle research

    NASA Astrophysics Data System (ADS)

    Toner, S. J.

    1981-07-01

    Experimental performance of converging-diverging nozzles operating on air-water mixtures is presented for a wide range of parameters. Thrust measurements characterized the performance and photographic documentation was used to visually observe the off-design regimes. Thirty-six nozzle configurations were tested to determine the effects of convergence angle, area ratio, and nozzle length. In addition, the pressure ratio and mass flowrate ratio were varied to experimentally map off-design performance. The test results indicate the effects of wall friction and infer temperature and velocity differences between phases and the effect on nozzle performance. The slip ratio between the phases, gas velocity to liquid velocity, is shown to be below about 4 or 5.

  3. Aeroacoustic Improvements to Fluidic Chevron Nozzles

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda; Kinzie, Kevin; Whitmire, Julia; Abeysinghe, Amal

    2006-01-01

    Fluidic chevrons use injected air near the trailing edge of a nozzle to emulate mixing and jet noise reduction characteristics of mechanical chevrons. While previous investigations of "first generation" fluidic chevron nozzles showed only marginal improvements in effective perceived noise levels when compared to nozzles without injection, significant improvements in noise reduction characteristics were achieved through redesigned "second generation" nozzles on a bypass ratio 5 model system. The second-generation core nozzles had improved injection passage contours, external nozzle contour lines, and nozzle trailing edges. The new fluidic chevrons resulted in reduced overall sound pressure levels over that of the baseline nozzle for all observation angles. Injection ports with steep injection angles produced lower overall sound pressure levels than those produced by shallow injection angles. The reductions in overall sound pressure levels were the result of noise reductions at low frequencies. In contrast to the first-generation nozzles, only marginal increases in high frequency noise over that of the baseline nozzle were observed for the second-generation nozzles. The effective perceived noise levels of the new fluidic chevrons are shown to approach those of the core mechanical chevrons.

  4. Effects of empennage surface location on aerodynamic characteristics of a twin-engine afterbody model with nonaxisymmetric nozzles

    NASA Technical Reports Server (NTRS)

    Capone, Francis J.; Carson, George T., Jr.

    1985-01-01

    An investigation has been conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of empennage surface location and vertical tail cant angle on the aft-end aerodynamic characteristics of a twin-engine fighter-type configuration. The configuration featured two-dimensional convergent-divergent nozzles and twin-vertical tails. The investigation was conducted with different empennage locations that included two horizontal and three vertical tail positions. Vertical tail cant angle was varied from -10 deg to 20 deg for one selected configuration. Tests were conducted at Mach number 0.60 to 1.20 and at angles of attack -3 to 9 deg. Nozzle pressure ratio was varied from jet off to approximately 9, depending upon Mach number. Tail interference effects were present throughout the range of Mach numbers tested and found to be either favorable or adverse, depending upon test condition and model configuration. At a Mach number of 0.90, adverse interference effects accounted for a significant percentage of total aft-end drag. Interference effects on the nozzle were generally favorable but became adverse as the horizontal tails were moved from a mid to an aft position. The configuration with nonaxisymmetric nozzles had lower total aft-end drag with tails-off than a similar configuration with axisymmetric nozzles at Mach numbers of 0.60 and 0.90.

  5. Flame structure of wall-impinging diesel fuel sprays injected by group-hole nozzles

    SciTech Connect

    Gao, Jian; Moon, Seoksu; Nishida, Keiya; Matsumoto, Yuhei; Zhang, Yuyin

    2009-06-15

    This paper describes an investigation of the flame structure of wall-impinging diesel sprays injected by group-hole nozzles in a constant-volume combustion vessel at experimental conditions typical of a diesel engine. The particular emphasis was on the effect of the included angle between two orifices (0-15 deg. in current study) on the flame structure and combustion characteristics under various simulated engine load conditions. The laser absorption scattering (LAS) technique was applied to analyze the spray and mixture properties. Direct flame imaging and OH chemiluminescence imaging were utilized to quantify the ignition delay, flame geometrical parameters, and OH chemiluminescence intensity. The images show that the asymmetric flame structure emerges in wall-impinging group-hole nozzle sprays as larger included angle and higher engine load conditions are applied, which is consistent with the spray shape observed by LAS. Compared to the base nozzle, group-hole nozzles with large included angles yield higher overall OH chemiluminescence intensity, wider flame area, and greater proportion of high OH intensity, implying the better fuel/air mixing and improved combustion characteristics. The advantages of group-hole nozzle are more pronounced under high load conditions. Based on the results, the feasibility of group-hole nozzle for practical direct injection diesel engines is also discussed. It is concluded that the asymmetric flame structure of a group-hole nozzle spray is favorable to reduce soot formation over wide engine loads. However, the hole configuration of the group-hole nozzle should be carefully considered so as to achieve proper air utilization in the combustion chamber. Stoichiometric diesel combustion is another promising application of group-hole nozzle. (author)

  6. Three-Dimensional Computational Model for Flow in an Over-Expanded Nozzle With Porous Surfaces

    NASA Technical Reports Server (NTRS)

    Abdol-Hamid, K. S.; Elmiligui, Alaa; Hunter, Craig A.; Massey, Steven J.

    2006-01-01

    A three-Dimensional computational model is used to simulate flow in a non-axisymmetric, convergent-divergent nozzle incorporating porous cavities for shock-boundary layer interaction control. The nozzle has an expansion ratio (exit area/throat area) of 1.797 and a design nozzle pressure ratio of 8.78. Flow fields for the baseline nozzle (no porosity) and for the nozzle with porous surfaces of 10% openness are computed for Nozzle Pressure Ratio (NPR) varying from 1.29 to 9.54. The three dimensional computational results indicate that baseline (no porosity) nozzle performance is dominated by unstable, shock-induced, boundary-layer separation at over-expanded conditions. For NPR less than or equal to 1.8, the separation is three dimensional, somewhat unsteady, and confined to a bubble (with partial reattachment over the nozzle flap). For NPR greater than or equal to 2.0, separation is steady and fully detached, and becomes more two dimensional as NPR increased. Numerical simulation of porous configurations indicates that a porous patch is capable of controlling off design separation in the nozzle by either alleviating separation or by encouraging stable separation of the exhaust flow. In the present paper, computational simulation results, wall centerline pressure, mach contours, and thrust efficiency ratio are presented, discussed and compared with experimental data. Results indicate that comparisons are in good agreement with experimental data. The three-dimensional simulation improves the comparisons for over-expanded flow conditions as compared with two-dimensional assumptions.

  7. Module Configuration

    DOEpatents

    Oweis, Salah; D'Ussel, Louis; Chagnon, Guy; Zuhowski, Michael; Sack, Tim; Laucournet, Gaullume; Jackson, Edward J.

    2002-06-04

    A stand alone battery module including: (a) a mechanical configuration; (b) a thermal management configuration; (c) an electrical connection configuration; and (d) an electronics configuration. Such a module is fully interchangeable in a battery pack assembly, mechanically, from the thermal management point of view, and electrically. With the same hardware, the module can accommodate different cell sizes and, therefore, can easily have different capacities. The module structure is designed to accommodate the electronics monitoring, protection, and printed wiring assembly boards (PWAs), as well as to allow airflow through the module. A plurality of modules may easily be connected together to form a battery pack. The parts of the module are designed to facilitate their manufacture and assembly.

  8. New Electrospinning Nozzle to Reduce Jet Instability and Its Application to Manufacture of Multi-layered Nanofibers

    PubMed Central

    Lee, Byoung-Sun; Jeon, Seung-Yeol; Park, Haedong; Lee, Geunsung; Yang, Ho-Sung; Yu, Woong-Ryeol

    2014-01-01

    A new nozzle system for the efficient production of multi-layered nanofibers through electrospinning is reported. Developed a decade ago, the commonly used coaxial nozzle system consisting of two concentric cylindrical needles has remained unchanged, despite recent advances in multi-layered, multi-functional nanofibers. Here, we demonstrate a core-cut nozzle system, in which the exit pipe of the core nozzle is removed such that the core fluid can form an envelope inside the shell solution. This configuration effectively improves the coaxial electrospinning behavior of two fluids and significantly reduces the jet instability, which was proved by finite element simulation. The proposed electrospinning nozzle system was then used to fabricate bi- and tri-layered carbon nanofibers. PMID:25342096

  9. Spray nozzle for fire control

    NASA Astrophysics Data System (ADS)

    Papavergos, Panayiotis G.

    1990-09-01

    The design of a spray nozzle for fire control is described. It produces a spray of gas and liquid having an oval transverse cross section and it comprises a mixing chamber with an oval transverse cross section adapted to induce a toroidal mixing pattern in pressurized gas and liquid introduced to the mixing chamber through a plurality of inlets. In a preferred embodiment the mixing chamber is toroidal. The spray nozzle produces an oval spray pattern for more efficient wetting of narrow passages and is suitable for fire control systems in vehicles or other confined spaces. Vehicles to which this invention may be applied include trains, armoured vehicles, ships, hovercraft, submarines, oil rigs, and most preferably, aircraft.

  10. Small drops from large nozzles

    NASA Astrophysics Data System (ADS)

    Castrejon-Pita, Alfonso Arturo; Said Mohamed, Ahmed; Castrejon-Pita, Jose Rafael; Herrada, Miguel Angel

    2015-11-01

    We report experimental and numerical results of the generation of drops which are significantly smaller than the nozzle from which they are generated. The system consists of a cylindrical reservoir and two endplates. One plate is a thin metal sheet with a small orifice in its centre which acts as the nozzle. The other end consists of a piston which moves by the action of an elecromechanical actuator which in turn is driven by sine-shape pull-mode pulses. The meniscus (formed at the nozzle) is thus first overturned, forming a cavity. This cavity collapses and a thin and fast jet emerges from its centre. Under appropriate conditions the tip of this jet breaks up and produces a single diminutive drop. A good agreement between the experimental and numerical results was found. Also, a series of experiments were performed in order to study the effects that the pulse amplitude and width, together with variations in the liquid properties, have over the final size of the droplet. Based on these experiments, a predictive law for the droplet size has been derived. This work was funded by the Royal Society (University Research Fellowship and Research Grant), the John Fell Fund (Oxford University Press), the Ministry of Science and Education (DPI2013-46485 Spain), and the Junta de Andalucia (P08-TEP-31704128 Spain).

  11. Frozen Chemistry Effects on Nozzle Performance Simulations

    NASA Technical Reports Server (NTRS)

    Yoder, Dennis A.; Georgiadis, Nicholas J.; O'Gara, Michael R.

    2009-01-01

    Simulations of exhaust nozzle flows are typically conducted assuming the gas is calorically perfect, and typically modeled as air. However the gas inside a real nozzle is generally composed of combustion products whose thermodynamic properties may differ. In this study, the effect of gas model assumption on exhaust nozzle simulations is examined. The three methods considered model the nozzle exhaust gas as calorically perfect air, a calorically perfect exhaust gas mixture, and a frozen exhaust gas mixture. In the latter case the individual non-reacting species are tracked and modeled as a gas which is only thermally perfect. Performance parameters such as mass flow rate, gross thrust, and thrust coefficient are compared as are mean flow and turbulence profiles in the jet plume region. Nozzles which operate at low temperatures or have low subsonic exit Mach numbers experience relatively minor temperature variations inside the nozzle, and may be modeled as a calorically perfect gas. In those which operate at the opposite extreme conditions, variations in the thermodynamic properties can lead to different expansion behavior within the nozzle. Modeling these cases as a perfect exhaust gas flow rather than air captures much of the flow features of the frozen chemistry simulations. Use of the exhaust gas reduces the nozzle mass flow rate, but has little effect on the gross thrust. When reporting nozzle thrust coefficient results, however, it is important to use the appropriate gas model assumptions to compute the ideal exit velocity. Otherwise the values obtained may be an overly optimistic estimate of nozzle performance.

  12. Nozzle Aerodynamic Stability During a Throat Shift

    NASA Technical Reports Server (NTRS)

    Kawecki, Edwin J.; Ribeiro, Gregg L.

    2005-01-01

    An experimental investigation was conducted on the internal aerodynamic stability of a family of two-dimensional (2-D) High Speed Civil Transport (HSCT) nozzle concepts. These nozzles function during takeoff as mixer-ejectors to meet acoustic requirements, and then convert to conventional high-performance convergent-divergent (CD) nozzles at cruise. The transition between takeoff mode and cruise mode results in the aerodynamic throat and the minimum cross-sectional area that controls the engine backpressure shifting location within the nozzle. The stability and steadiness of the nozzle aerodynamics during this so called throat shift process can directly affect the engine aerodynamic stability, and the mechanical design of the nozzle. The objective of the study was to determine if pressure spikes or other perturbations occurred during the throat shift process and, if so, identify the caused mechanisms for the perturbations. The two nozzle concepts modeled in the test program were the fixed chute (FC) and downstream mixer (DSM). These 2-D nozzles differ principally in that the FC has a large over-area between the forward throat and aft throat locations, while the DSM has an over-area of only about 10 percent. The conclusions were that engine mass flow and backpressure can be held constant simultaneously during nozzle throat shifts on this class of nozzles, and mode shifts can be accomplished at a constant mass flow and engine backpressure without upstream pressure perturbations.

  13. High-Area-Ratio Rocket Nozzle at High Combustion Chamber Pressure: Experimental and Analytical Validation

    NASA Technical Reports Server (NTRS)

    Jankovsky, Robert S.; Smith, Timothy D.; Pavli, Albert J.

    1999-01-01

    Experimental data were obtained on an optimally contoured nozzle with an area ratio of 1025:1 and on a truncated version of this nozzle with an area ratio of 440:1. The nozzles were tested with gaseous hydrogen and liquid oxygen propellants at combustion chamber pressures of 1800 to 2400 psia and mixture ratios of 3.89 to 6.15. This report compares the experimental performance, heat transfer, and boundary layer total pressure measurements with theoretical predictions of the current Joint Army, Navy, NASA, Air Force (JANNAF) developed methodology. This methodology makes use of the Two-Dimensional Kinetics (TDK) nozzle performance code. Comparisons of the TDK-predicted performance to experimentally attained thrust performance indicated that both the vacuum thrust coefficient and the vacuum specific impulse values were approximately 2.0-percent higher than the turbulent prediction for the 1025:1 configurations, and approximately 0.25-percent higher than the turbulent prediction for the 440:1 configuration. Nozzle wall temperatures were measured on the outside of a thin-walled heat sink nozzle during the test fittings. Nozzle heat fluxes were calculated front the time histories of these temperatures and compared with predictions made with the TDK code. The heat flux values were overpredicted for all cases. The results range from nearly 100 percent at an area ratio of 50 to only approximately 3 percent at an area ratio of 975. Values of the integral of the heat flux as a function of nozzle surface area were also calculated. Comparisons of the experiment with analyses of the heat flux and the heat rate per axial length also show that the experimental values were lower than the predicted value. Three boundary layer rakes mounted on the nozzle exit were used for boundary layer measurements. This arrangement allowed total pressure measurements to be obtained at 14 different distances from the nozzle wall. A comparison of boundary layer total pressure profiles and analytical

  14. High Electricity Demand in the Northeast U.S.: PJM Reliability Network and Peaking Unit Impacts on Air Quality.

    PubMed

    Farkas, Caroline M; Moeller, Michael D; Felder, Frank A; Henderson, Barron H; Carlton, Annmarie G

    2016-08-01

    On high electricity demand days, when air quality is often poor, regional transmission organizations (RTOs), such as PJM Interconnection, ensure reliability of the grid by employing peak-use electric generating units (EGUs). These "peaking units" are exempt from some federal and state air quality rules. We identify RTO assignment and peaking unit classification for EGUs in the Eastern U.S. and estimate air quality for four emission scenarios with the Community Multiscale Air Quality (CMAQ) model during the July 2006 heat wave. Further, we population-weight ambient values as a surrogate for potential population exposure. Emissions from electricity reliability networks negatively impact air quality in their own region and in neighboring geographic areas. Monitored and controlled PJM peaking units are generally located in economically depressed areas and can contribute up to 87% of hourly maximum PM2.5 mass locally. Potential population exposure to peaking unit PM2.5 mass is highest in the model domain's most populated cities. Average daily temperature and national gross domestic product steer peaking unit heat input. Air quality planning that capitalizes on a priori knowledge of local electricity demand and economics may provide a more holistic approach to protect human health within the context of growing energy needs in a changing world. PMID:27385064

  15. High Electricity Demand in the Northeast U.S.: PJM Reliability Network and Peaking Unit Impacts on Air Quality.

    PubMed

    Farkas, Caroline M; Moeller, Michael D; Felder, Frank A; Henderson, Barron H; Carlton, Annmarie G

    2016-08-01

    On high electricity demand days, when air quality is often poor, regional transmission organizations (RTOs), such as PJM Interconnection, ensure reliability of the grid by employing peak-use electric generating units (EGUs). These "peaking units" are exempt from some federal and state air quality rules. We identify RTO assignment and peaking unit classification for EGUs in the Eastern U.S. and estimate air quality for four emission scenarios with the Community Multiscale Air Quality (CMAQ) model during the July 2006 heat wave. Further, we population-weight ambient values as a surrogate for potential population exposure. Emissions from electricity reliability networks negatively impact air quality in their own region and in neighboring geographic areas. Monitored and controlled PJM peaking units are generally located in economically depressed areas and can contribute up to 87% of hourly maximum PM2.5 mass locally. Potential population exposure to peaking unit PM2.5 mass is highest in the model domain's most populated cities. Average daily temperature and national gross domestic product steer peaking unit heat input. Air quality planning that capitalizes on a priori knowledge of local electricity demand and economics may provide a more holistic approach to protect human health within the context of growing energy needs in a changing world.

  16. An improved numerical procedure for the parametric optimization of three dimensional scramjet nozzles. [supersonic combustion ramjet engines - computer programs

    NASA Technical Reports Server (NTRS)

    Dash, S.; Delguidice, P. D.

    1975-01-01

    A parametric numerical procedure permitting the rapid determination of the performance of a class of scramjet nozzle configurations is presented. The geometric complexity of these configurations ruled out attempts to employ conventional nozzle design procedures. The numerical program developed permitted the parametric variation of cowl length, turning angles on the cowl and vehicle undersurface and lateral expansion, and was subject to fixed constraints such as the vehicle length and nozzle exit height. The program required uniform initial conditions at the burner exit station and yielded the location of all predominant wave zones, accounting for lateral expansion effects. In addition, the program yielded the detailed pressure distribution on the cowl, vehicle undersurface and fences, if any, and calculated the nozzle thrust, lift and pitching moments.

  17. Aeropropulsive characteristics of isolated combined turbojet/ramjet nozzles at Mach numbers from 0 to 1.20

    NASA Technical Reports Server (NTRS)

    Carson, George T., Jr.; Lamb, Milton

    1988-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the aeropropulsive performance characteristics (the aerodynamic quantities affected by propulsion) of 13 isolated combined turbojet/ramjet nozzle configurations. These configurations simulated the variable-geometry features of two nozzle designs designated as the multiple-expansion ramp nozzle (MERN) and the composite contour nozzle (CCN). Test data were obtained at static conditions and at Mach numbers of 0.60, 0.90, and 1.20 with jet exhaust simulated by high-pressure air. The results showed that the CCN had the higher performance over the Mach number range than the MERN, as indicated by the difference of thrust minus drag divided by ideal thrust. Increasing the ramjet throat area for the MERN resulted in an increase in performance that increased with Mach number. For the CCN at Mach numbers less than 1.20, increasing the ramjet throat area resulted in a loss in performance.

  18. Flight effects on the aerodynamic and acoustic characteristics of inverted profile coannular nozzles, volume 3. [supersonic cruise aircraft research wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.

    1978-01-01

    Acoustic data from tests of the 0.75 area ratio coannular nozzle with ejector and the 1.2 area ratio coannular are presented in tables. Aerodynamic data acquired for the four test configurations are included.

  19. Assessment at full scale of nozzle/wing geometry effects on OTW aero-acoustic characteristics. [short takeoff aircraft noise

    NASA Technical Reports Server (NTRS)

    Groesbeck, D.; Vonglahn, U.

    1979-01-01

    The effects on acoustic characteristics of nozzle type and location on a wing for STOL engine over-the-wing configurations are assessed at full scale on the basis of model-scale data. Three types of nozzle configurations are evaluated: a circular nozzle with external deflector mounted above the wing, a slot nozzle with external deflector mounted on the wing and a slot nozzle mounted on the wing. Nozzle exhaust plane locations with respect to the wing leading edge are varied from 10 to 46 percent chord (flaps retracted) with flap angles of 20 (takeoff altitude) and 60 (approach attitude). Perceived noise levels (PNL) are calculated as a function of flyover distance at 152 m altitude. From these plots, static EPNL values, defined as flyover relative noise levels, are calculated and plotted as a function of lift and thrust ratios. From such plots the acoustic benefits attributable to variations in nozzle/deflector/wing geometry at full scale are assessed for equal aerodynamic performance.

  20. A Numerical Simulation and Comparison of Cutting Fluid Flow Characteristics through Gradual Contraction and Sudden Contraction Nozzle

    NASA Astrophysics Data System (ADS)

    Ghadai, Ranjan Kumar; Kalita, Kanak; Guha, Ashim; Chakrabarti, Somnath

    2016-06-01

    Cutting fluid delivery plays an important role in every machining operation. Cutting fluid is generally delivered by a gradual converging nozzle. The present work shows an extensive numerical study on the performance of cutting fluid flow through gradual converging and sudden converging nozzles. The Nevier-Stokes and continuity equations are solved using the commercial CFD software FLUENT 6.3.26 that employs the control volume technique on a uniform staggered grid following the SIMPLE algorithm. For the sudden contraction configuration, two contraction ratios, 0.28 and 0.55, are taken. The following variables and their variations are computed for both sudden and gradual contraction: wall static pressure (WSP), wall shear stress (WSS), and centerline velocity (Vcenterline). For both gradual and sudden contraction, WSP, WSS, and Vcenterline increase with increases in Reynolds number. For a particular Re, the WSP decreases with increases in the length from the throat for both nozzle types. In the gradual converging nozzle, the WSS and Vcenterline increase with increases in the length from the throat; in contrast, in the sudden contraction configuration, the Vcenterline increases up to a few distances from the throat and afterward remains same up to the exit of the nozzle. For the same amount of increase in Vcenterline, the suddenly converging nozzle requires shorter lengths than the gradually converging nozzle.

  1. Acoustic, performance, and wake survey measurements of a lobed velocity-decayer nozzle installed on a quieted TF-34 turbofan engine

    NASA Technical Reports Server (NTRS)

    Samanich, N. E.; Heidelberg, L. J.

    1976-01-01

    Results for three velocity decayer nozzle configurations are compared with those obtained with a separate flow coannular nozzle tested on the same quieted turbofan engine. Peak sideline noise, which occurred 110 degrees from the inlet, was 2 to 4 db louder than with the coannular nozzle at the same ideal effective exhaust velocity and 8 to 11 db louder at the same thrust level. The decayer nozzles produced an increase in loss equivalent to about 4 percent of the engine thrust and also increased the effective exhaust velocity of the engine. The exhaust decayed to 0.35 of its peak velocity, compared with no decay for the coannular nozzle, within 3 equivalent nozzle diameters of the exit. The peak exhaust gas temperature was 400 K lower for the decayer configuration at the same location. The increase in perceived noise level for the decayer nozzles as compared with the coannular nozzle was attributed to the increase in exhaust velocity and the shift in peak spectrum frequency produced by these nozzles.

  2. Support pedestals for interconnecting a cover and nozzle band wall in a gas turbine nozzle segment

    DOEpatents

    Yu, Yufeng Phillip; Itzel, Gary Michael; Webbon, Waylon Willard; Bagepalli, Radhakrishna; Burdgick, Steven Sebastian; Kellock, Iain Robertson

    2002-01-01

    A gas turbine nozzle segment has outer and inner band portions. Each band portion includes a nozzle wall, a cover and an impingement plate between the cover and nozzle wall defining two cavities on opposite sides of the impingement plate. Cooling steam is supplied to one cavity for flow through the apertures of the impingement plate to cool the nozzle wall. Structural pedestals interconnect the cover and nozzle wall and pass through holes in the impingement plate to reduce localized stress otherwise resulting from a difference in pressure within the chamber of the nozzle segment and the hot gas path and the fixed turbine casing surrounding the nozzle stage. The pedestals may be cast or welded to the cover and nozzle wall.

  3. Insert metering plates for gas turbine nozzles

    DOEpatents

    Burdgick, Steven S.; Itzel, Gary; Chopra, Sanjay; Abuaf, Nesim; Correia, Victor H.

    2004-05-11

    The invention comprises a metering plate which is assembled to an impingement insert for use in the nozzle of a gas turbine. The metering plate can have one or more metering holes and is used to balance the cooling flow within the nozzle. A metering plate with multiple holes reduces static pressure variations which result from the cooling airflow through the metering plate. The metering plate can be assembled to the insert before or after the insert is inserted into the nozzle.

  4. NPAC-Nozzle Performance Analysis Code

    NASA Technical Reports Server (NTRS)

    Barnhart, Paul J.

    1997-01-01

    A simple and accurate nozzle performance analysis methodology has been developed. The geometry modeling requirements are minimal and very flexible, thus allowing rapid design evaluations. The solution techniques accurately couple: continuity, momentum, energy, state, and other relations which permit fast and accurate calculations of nozzle gross thrust. The control volume and internal flow analyses are capable of accounting for the effects of: over/under expansion, flow divergence, wall friction, heat transfer, and mass addition/loss across surfaces. The results from the nozzle performance methodology are shown to be in excellent agreement with experimental data for a variety of nozzle designs over a range of operating conditions.

  5. Turbulence Measurements of Rectangular Nozzles with Bevel

    NASA Technical Reports Server (NTRS)

    Bridges, James; Wernet, Mark P.

    2015-01-01

    This paper covers particle image velocimetry measurements of a family of rectangular nozzles with aspect ratios 2, 4, and 8, in the high subsonic flow regime. Far-field acoustic results, presented previously, showed that increasing aspect ratios increased the high frequency noise, especially directed in the polar plane containing the minor axis of the nozzle. The measurements presented here have important implications in the modeling of turbulent sources for acoustic analogy theories. While the nonaxisymmetric mean flow from the rectangular nozzles can be studied reliably using computational solutions, the nonaxisymmetry of the turbulent fluctuations, particularly at the level of velocity components, cannot; only measurements such as these can determine the impact of nozzle geometry on acoustic source anisotropy. Additional nozzles were constructed that extended the wide lip on one side of these nozzles to form beveled nozzles. The paper first documents the velocity fields, mean and variance, from the round, rectangular, and beveled rectangular nozzles at high subsonic speeds. A second section introduces measures of the isotropy of the turbulence, such as component ratios and lengthscales, first by showing them for a round jet and then for the rectangular nozzles. From these measures the source models of acoustic analogy codes can be judged or modified to account for these anisotropies.

  6. Analysis of solid rocket motor nozzle

    NASA Astrophysics Data System (ADS)

    Lapp, P.; Quesada, B.

    1992-07-01

    Advancements in numerical optimization and the fabrication of high performance carbon-carbon (C/C) composites have resulted in significant simplifications of nozzle designs, with attendant production cost reductions and reliability enhancements. An account is presently given of the analysis methods associated with C/C nozzles and of results of their comparison with experimental data. Attention is given to the analytical methods' application in the cases of the Ariane 5 solid rocket nozzle and a new, advanced solid rocket motor C/C nozzle.

  7. Did Geomagnetic Activity Challenge Electric Power Reliability During Solar Cycle 23? Evidence from the PJM Regional Transmission Organization in North America

    NASA Technical Reports Server (NTRS)

    Forbes, Kevin F.; Cyr, Chris St

    2012-01-01

    During solar cycle 22, a very intense geomagnetic storm on 13 March 1989 contributed to the collapse of the Hydro-Quebec power system in Canada. This event clearly demonstrated that geomagnetic storms have the potential to lead to blackouts. This paper addresses whether geomagnetic activity challenged power system reliability during solar cycle 23. Operations by PJM Interconnection, LLC (hereafter PJM), a regional transmission organization in North America, are examined over the period 1 April 2002 through 30 April 2004. During this time PJM coordinated the movement of wholesale electricity in all or parts of Delaware, Maryland, New Jersey, Ohio, Pennsylvania, Virginia, West Virginia, and the District of Columbia in the United States. We examine the relationship between a proxy of geomagnetically induced currents (GICs) and a metric of challenged reliability. In this study, GICs are proxied using magnetometer data from a geomagnetic observatory located just outside the PJM control area. The metric of challenged reliability is the incidence of out-of-economic-merit order dispatching due to adverse reactive power conditions. The statistical methods employed make it possible to disentangle the effects of GICs on power system operations from purely terrestrial factors. The results of the analysis indicate that geomagnetic activity can significantly increase the likelihood that the system operator will dispatch generating units based on system stability considerations rather than economic merit.

  8. Acoustic and Aero-Mixing Experimental Results for Fluid Shield Scale Model Nozzles

    NASA Technical Reports Server (NTRS)

    Salikuddin, M.; Mengle, V. G.; Shin, H. W.; Majjigi, R. K.

    2005-01-01

    The principle objectives of this investigation are to evaluate the acoustic and aerodynamic characteristics of fluid shield nozzle concept and to assess Far 36, Stage 3 potential for fluid shield nozzle with Flade Cycle. Acoustic data for nine scale model nozzle configurations are obtained. The effects of simulated flight and geometric and aerothermodynamic flow variables on the acoustic behavior of the fluid shield are determined. The acoustic tests are aimed at studying the effect of: (1) shield thickness, (2) wrap angle, (3) mass flow and velocity ratios between shield and core streams at constant cycle specific thrust (i.e., mixed velocity), (4) porous plug, and (5) subsonic shield. Shadowgraphs of six nozzle configurations are obtained to understand the plume flowfield features. Static pressure data on suppressor chutes in the core stream (shielded and unshielded) sides and on plug surface are acquired to determine the impact of fluid shield on base drag of the 36-chute suppressor nozzle and the thrust augmentation due to the plug, respectively.

  9. Static Thrust and Vectoring Performance of a Spherical Convergent Flap Nozzle with a Nonrectangular Divergent Duct

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    1998-01-01

    The static internal performance of a multiaxis-thrust-vectoring, spherical convergent flap (SCF) nozzle with a non-rectangular divergent duct was obtained in the model preparation area of the Langley 16-Foot Transonic Tunnel. Duct cross sections of hexagonal and bowtie shapes were tested. Additional geometric parameters included throat area (power setting), pitch flap deflection angle, and yaw gimbal angle. Nozzle pressure ratio was varied from 2 to 12 for dry power configurations and from 2 to 6 for afterburning power configurations. Approximately a 1-percent loss in thrust efficiency from SCF nozzles with a rectangular divergent duct was incurred as a result of internal oblique shocks in the flow field. The internal oblique shocks were the result of cross flow generated by the vee-shaped geometric throat. The hexagonal and bowtie nozzles had mirror-imaged flow fields and therefore similar thrust performance. Thrust vectoring was not hampered by the three-dimensional internal geometry of the nozzles. Flow visualization indicates pitch thrust-vector angles larger than 10' may be achievable with minimal adverse effect on or a possible gain in resultant thrust efficiency as compared with the performance at a pitch thrust-vector angle of 10 deg.

  10. Numerical simulation of shock-induced separated flows in overexpanded rocket nozzles

    NASA Astrophysics Data System (ADS)

    Shams, A.; Girard, S.; Comte, P.

    2012-01-01

    Flow separation in rocket nozzles is undesirable because of its unsteady and nonsymmetric nature, which leads to dangerous side-loads. At the initial stages of start-up, when a thrust optimized contour (TOC) nozzle operates under overexpanded conditions, free shock separation (FSS) takes place. Under certain conditions, this free separated flow reattaches back to the nozzle wall and forms restricted shock separation (RSS). The appearance of restricted shock separated flow depends upon the nozzle contour in a well-defined range of nozzle pressure ratios (NPR) and is characterized by a cap-shock pattern. The flow transition process from FSS to RSS flow configurations is a complex phenomenon and has been an area of interest for a few decades now. In the present study, an attempt has been made to understand the formation of the cap-shock pattern and the RSS flow configuration in a thrust optimized contour (TOC) nozzle. The presented research work consists of two parts. In the first part of the paper, numerical investigation of flow transition (FSS→RSS) has been performed to understand the formation of the cap-shock pattern, which is believed to be the main cause for this flow transition from FSS to RSS. Axisymmetric numerical calculations on a wide range of NPRs (15 25) are performed to reproduce the forward transition process and are found to be in good agreement with the experiments. In the second part, some light has been shed on various aspects of RSS flow regime. Three-dimensional (3D) numerical simulations have been performed on a wide range of NPRs, i. e., 25.0, 30.0, 38.0, 41.0, and 46.0. Detailed analysis of these numerical results allows examining the evolution of the separation point and the cap-shock pattern with respect to the NPR. Furthermore, some insights based on the axial momentum along the nozzle axis and radial momentum distributions across the quadruple point are given.

  11. Structural strengthening of rocket nozzle extension by means of laser metal deposition

    NASA Astrophysics Data System (ADS)

    Honoré, M.; Brox, L.; Hallberg, M.

    2012-03-01

    Commercial space operations strive to maximize the payload per launch in order to minimize the costs of each kg launched into orbit; this yields demand for ever larger launchers with larger, more powerful rocket engines. Volvo Aero Corporation in collaboration with Snecma and Astrium has designed and tested a new, upgraded Nozzle extension for the Vulcain 2 engine configuration, denoted Vulcain 2+ NE Demonstrator The manufacturing process for the welding of the sandwich wall and the stiffening structure is developed in close cooperation with FORCE Technology. The upgrade is intended to be available for future development programs for the European Space Agency's (ESA) highly successful commercial launch vehicle, the ARIANE 5. The Vulcain 2+ Nozzle Extension Demonstrator [1] features a novel, thin-sheet laser-welded configuration, with laser metal deposition built-up 3D-features for the mounting of stiffening structure, flanges and for structural strengthening, in order to cope with the extreme load- and thermal conditions, to which the rocket nozzle extension is exposed during launch of the 750 ton ARIANE 5 launcher. Several millimeters of material thickness has been deposited by laser metal deposition without disturbing the intricate flow geometry of the nozzle cooling channels. The laser metal deposition process has been applied on a full-scale rocket nozzle demonstrator, and in excess of 15 kilometers of filler wire has been successfully applied to the rocket nozzle. The laser metal deposition has proven successful in two full-throttle, full-scale tests, firing the rocket engine and nozzle in the ESA test facility P5 by DLR in Lampoldshausen, Germany.

  12. Making Nozzles From Hard Materials

    NASA Technical Reports Server (NTRS)

    Wells, Dennis L.

    1989-01-01

    Proposed method of electrical-discharge machining (EDM) cuts hard materials like silicon carbide into smoothly contoured parts. Concept developed for fabrication of interior and exterior surfaces and internal cooling channels of convergent/divergent nozzles. EDM wire at skew angle theta creates hyperboloidal cavity in tube. Wire offset from axis of tube and from axis of rotation by distance equal to throat radius. Maintaining same skew angle as that used to cut hyperboloidal inner surface but using larger offset, cooling channel cut in material near inner hyperboloidal surface.

  13. Design Of A SCRAMJET Nozzle With Streamline Tracing Technique And Reference Temerature Methode

    NASA Astrophysics Data System (ADS)

    Riehmer, J.; Gulhan, A.

    2011-05-01

    This study presents a method to find an optimal shape of a three-dimensional supersonic nozzle for a rectangular scramjet combustion chamber with rounded edges by taking into account the skin friction effects. The geometric and flow constraints are defined within the German DFG GRK 1095/2 project and the designed nozzle will be part of a scramjet demonstrator configuration [1]. The nozzle inlet conditions are mean values of the combustion chamber exit conditions with the assumption of a constant specific heat ratio. To generate the shape of the nozzle a streamline tracing technique is applied to an axis-symmetric flow field calculated by the Method of Characteristics (MOC). Skin friction in relatively high pressure supersonic flow from the combustion chamber is very dominant and cannot be neglected in the design process. Therefore the skin friction is calculated using the Reference Temperature Method (RTM) and used for the determination of the thrust and moment vectors. This allows considering viscous effects without boundary layer calculations. With this approach an optimal truncated ideal nozzle contour which yields the geometric constraints can be derived. For the validation of this method comparative calculations have been carried out with the DLR code TAU on an exemplary axis-symmetric supersonic nozzle for different flow conditions. Results showed a good agreement. Finally for the three-dimensional nozzle the analytical solution for the inviscous and viscous case provided comparable data like TAU simulations. Further simplifications of the approach for an efficient three-dimensional nozzle design will be addressed in the paper.

  14. Temperature Dependent Modal Test/Analysis Correlation of X-34 Fastrac Composite Rocket Nozzle

    NASA Technical Reports Server (NTRS)

    Brown, Andrew M.; Brunty, Joseph A. (Technical Monitor)

    2001-01-01

    A unique high temperature modal test and model correlation/update program has been performed on the composite nozzle of the FASTRAC engine for the NASA X-34 Reusable Launch Vehicle. The program was required to provide an accurate high temperature model of the nozzle for incorporation into the engine system structural dynamics model for loads calculation; this model is significantly different from the ambient case due to the large decrease in composite stiffness properties due to heating. The high-temperature modal test was performed during a hot-fire test of the nozzle. Previously, a series of high fidelity modal tests and finite element model correlation of the nozzle in a free-free configuration had been performed. This model was then attached to a modal-test verified model of the engine hot-fire test stand and the ambient system mode shapes were identified. A reduced set of accelerometers was then attached to the nozzle, the engine fired full-duration, and the frequency peaks corresponding to the ambient nozzle modes individually isolated and tracked as they decreased during the test. To update the finite-element model of the nozzle to these frequency curves, the percentage differences of the anisotropic composite moduli due to temperature variation from ambient, which had been used in the initial modeling and which were obtained by small sample coupon testing, were multiplied by an iteratively determined constant factor. These new properties were used to create high-temperature nozzle models corresponding to 10 second engine operation increments and tied into the engine system model for loads determination.

  15. Static performance investigation of a skewed-throat multiaxis thrust-vectoring nozzle concept

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    1994-01-01

    The static performance of a jet exhaust nozzle which achieves multiaxis thrust vectoring by physically skewing the geometric throat has been characterized in the static test facility of the 16-Foot Transonic Tunnel at NASA Langley Research Center. The nozzle has an asymmetric internal geometry defined by four surfaces: a convergent-divergent upper surface with its ridge perpendicular to the nozzle centerline, a convergent-divergent lower surface with its ridge skewed relative to the nozzle centerline, an outwardly deflected sidewall, and a straight sidewall. The primary goal of the concept is to provide efficient yaw thrust vectoring by forcing the sonic plane (nozzle throat) to form at a yaw angle defined by the skewed ridge of the lower surface contour. A secondary goal is to provide multiaxis thrust vectoring by combining the skewed-throat yaw-vectoring concept with upper and lower pitch flap deflections. The geometric parameters varied in this investigation included lower surface ridge skew angle, nozzle expansion ratio (divergence angle), aspect ratio, pitch flap deflection angle, and sidewall deflection angle. Nozzle pressure ratio was varied from 2 to a high of 11.5 for some configurations. The results of the investigation indicate that efficient, substantial multiaxis thrust vectoring was achieved by the skewed-throat nozzle concept. However, certain control surface deflections destabilized the internal flow field, which resulted in substantial shifts in the position and orientation of the sonic plane and had an adverse effect on thrust-vectoring and weight flow characteristics. By increasing the expansion ratio, the location of the sonic plane was stabilized. The asymmetric design resulted in interdependent pitch and yaw thrust vectoring as well as nonzero thrust-vector angles with undeflected control surfaces. By skewing the ridges of both the upper and lower surface contours, the interdependency between pitch and yaw thrust vectoring may be eliminated

  16. Nozzle

    DOEpatents

    Chen, Alexander G.; Fotache, Catalin G.

    2008-04-01

    The fuel injector has a first means defining a number of flowpaths each having an inlet for receiving air and an outlet for discharging a fuel/air mixture. One or more arrays of vanes are each positioned to impart swirl to an associated one or more of the flowpaths. Second means are provided for introducing the fuel to the air.

  17. Method and apparatus for setting precise nozzle/belt and nozzle/edge dam block gaps

    DOEpatents

    Carmichael, Robert J.; Dykes, Charles D.; Woodrow, Ronald

    1989-05-16

    A pair of guide pins are mounted on sideplate extensions of the caster and mating roller pairs are mounted on the nozzle assembly. The nozzle is advanced toward the caster so that the roller pairs engage the guide pins. Both guide pins are remotely adjustable in the vertical direction by hydraulic cylinders acting through eccentrics. This moves the nozzle vertically. The guide pin on the inboard side of the caster is similarly horizontally adjustable. The nozzle roller pair which engage the inboard guide pin are flanged so that the nozzle moves horizontally with the inboard guide pin.

  18. Grade Configuration

    ERIC Educational Resources Information Center

    Williamson, Ronald

    2012-01-01

    Where to locate the 7th and 8th grade is a perennial question. While there are many variations, three approaches are most often used---include them in a 7-12 secondary campus, maintain a separate middle grades campus, or include them as part of a K-8 program. Research says that grade configuration is inconclusive at best and there is no research…

  19. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y. H.; Chen, Da-Ren

    2015-06-09

    Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

  20. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y.H.; Chen, Da-Ren

    2004-07-20

    Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

  1. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y. H.; Chen, Da-Ren

    2009-03-03

    Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

  2. Nozzle extension design status report

    NASA Technical Reports Server (NTRS)

    Classen, L. B.

    1972-01-01

    Twenty possible concepts of a possible nozzle/nozzle extension interface were originated. Not all of the concepts were considered worthy of analysis time. Six of them were thermally analyzed and three were stress analyzed. These analyses were done to determine which of the concepts would have the best chance of succeeding, that is, they were a screening process which was to allow rating of one concept against another. This was done because adequate material properties to determine absolute stress levels were not available at the time of the analyses. Through all of the concepts still exhibit some areas of negative margin of safety, concept no. 1 shows good promise that, with slight modifications, it could have all positive margins of safety. Another significant question, regarding these designs, has to do with the Grafoil seals and insulators. Some additional data was just recently received on Grafoil properties, but it was too late to incorporate in the analyses. The new data were not significantly different from the properties which were used.

  3. Fingernail Configuration

    PubMed Central

    Jung, Jin Woo; Shin, Jun Ho; Kwon, Yu Jin; Hwang, Jae Ha; Lee, Sam Yong

    2015-01-01

    Background A number of conditions can alter a person's fingernail configuration. The ratio between fingernail width and length (W/L) is an important aesthetic criterion, and some underlying diseases can alter the size of the fingernail. Fingernail curvature can be altered by systemic disorders or disorders of the fingernail itself. Although the shape and curvature of the fingernail can provide diagnostic clues for various diseases, few studies have precisely characterized normal fingernail configuration. Methods We measured the W/L ratio of the fingernail, transverse fingernail curvature, hand length, hand breadth, and distal interphalangeal joint width in 300 volunteers with healthy fingernails. We also investigated whether age, sex, height, and handedness influenced the fingernail W/L ratio and transverse fingernail curvature. Results In women, fingernail W/L ratios were similar across all five fingers, and were lower than those in men. The highest value of transverse fingernail curvature was found in the thumb, followed by the index, middle, ring, and little fingers. Handedness and aging influenced transverse fingernail curvature, but not the fingernail W/L ratio. Fingernails were flatter on the dominant hand than on the non-dominant hand. The radius of transverse fingernail curvature increased with age, indicating that fingernails tended to flatten with age. Conclusions Our quantitative data on fingernail configuration can be used as a reference range for diagnosing various diseases and deformities of the fingernail, and for performing reconstructive or aesthetic fingernail surgery. PMID:26618124

  4. Erosion-Resistant Water-Blast Nozzle

    NASA Technical Reports Server (NTRS)

    Roberts, Marion L.; Rice, R. M.; Cosby, S. A.

    1988-01-01

    Design of nozzle reduces erosion of orifice by turbulent high-pressure water flowing through it. Improved performance and resistance to erosion achieved by giving interior nozzle surface long, gradual convergence before exit orifice abrupt divergence after orifice and by machining surface to smooth finish.

  5. Nitrous oxide cooling in hybrid rocket nozzles

    NASA Astrophysics Data System (ADS)

    Lemieux, Patrick

    2010-02-01

    The Department of Mechanical Engineering at the California Polytechnic State University, San Luis Obispo, has developed an innovative program of experimental research and development on hybrid rocket motors (where the fuel and the oxidizer are in different phases prior to combustion). One project currently underway involves the development of aerospike nozzles for such motors. These nozzles, however, are even more susceptible to throat ablation than regular converging-diverging nozzles, due the nature of their flow expansion mechanism. This paper presents the result of a recent development project focused on reducing throat ablation in hybrid rocket motor nozzles. Although the method is specifically targeted at increasing the life and operating range of aerospike nozzles, this paper describes its proof-of-concept implementation on conventional nozzles. The method is based on a regenerative cooling mechanism that differs in practice from that used in liquid propellant motors. A series of experimental tests demonstrate that this new method is not only effective at reducing damage in the most ablative region of the nozzle, but that the nozzle can survive multiple test runs.

  6. Exhaust Nozzle Plume Effects on Sonic Boom Test Results for Isolated Nozzles

    NASA Technical Reports Server (NTRS)

    Castner, Raymond S.

    2011-01-01

    Reducing or eliminating the operational restrictions of supersonic aircraft over populated areas has led to extensive research at NASA. Restrictions were due to the disturbance of the sonic boom, caused by the coalescence of shock waves formed off the aircraft. Recent work has been performed to reduce the magnitude of the sonic boom N-wave generated by airplane components with focus on shock waves caused by the exhaust nozzle plume. Previous Computational Fluid Dynamics (CFD) analysis showed how the shock wave formed at the nozzle lip interacts with the nozzle boat-tail expansion wave. An experiment was conducted in the 1- by 1-ft Supersonic Wind Tunnel at the NASA Glenn Research Center to validate the computational study. Results demonstrated how the nozzle lip shock moved with increasing nozzle pressure ratio (NPR) and reduced the nozzle boat-tail expansion, causing a favorable change in the observed pressure signature. Experimental results were presented for comparison to the CFD results. The strong nozzle lip shock at high values of NPR intersected the nozzle boat-tail expansion and suppressed the expansion wave. Based on these results, it may be feasible to reduce the boat-tail expansion for a future supersonic aircraft with under-expanded nozzle exhaust flow by modifying nozzle pressure or nozzle divergent section geometry.

  7. Mach Reflection, Mach Disc, and the Associated Nozzle Free Jet Flows. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Chang, I.

    1973-01-01

    The numerical method involving both the method of integral relations and the method of characteristics have been applied to investigate the steady flow phenomena associated with the accurrence of Mach reflection and Mach disc from nozzle flows. The solutions of triple-shock intersection are presented. The regime where Mach configuration appears is defines for the inviscid analysis. The method of integral relations developed for the blunt body problem is modified and extended to the attached shock wave and to internal nozzle flow problems.

  8. Static Internal Performance of a Two-Dimensional Convergent-Divergent Nozzle with External Shelf

    NASA Technical Reports Server (NTRS)

    Lamb, Milton; Taylor, John G.; Frassinelli, Mark C.

    1996-01-01

    An investigation was conducted in the static test facility of the Langley 16-Foot Transonic Tunnel to determine the internal performance of a two-dimensional convergent-divergent nozzle. The nozzle design was tested with dry and afterburning throat areas, which represent different power settings and three expansion ratios. For each of these configurations, three trailing-edge geometries were tested. The baseline geometry had a straight trailing edge. Two different shaping techniques were applied to the baseline nozzle design to reduce radar observables: the scarfed design and the sawtooth design. A flat plate extended downstream of the lower divergent flap trailing edge parallel to the model centerline to form a shelf-like expansion surface. This shelf was designed to shield the plume from ground observation (infrared radiation (IR) signature suppression). The shelf represents the part of the aircraft structure that might be present in an installed configuration. These configurations were tested at nozzle pressure ratios from 2.0 to 12.0.

  9. Static and wind-on tests of an upper-surface-blown jet-flap nozzle arrangement for use on the Quiet Clean Short-haul Experimental Engine (QCSEE)

    NASA Technical Reports Server (NTRS)

    Phelps, A. E., III

    1977-01-01

    The internal aerodynamic performance, the static turning characteristics, and the forward-speed characteristics of two 1/12-scale upper surface-blown jet-flap exhaust-nozzle arrangements designed for use on the Quiet Clean Short-Haul Experimental Engine (QCSEE) were investigated. The nozzles were equipped with interchangeable area-control side doors in the aft sidewalls of the nozzle so that the effective nozzle area could be varied over a wide range. A simulated wing was used to evaluate installation losses for the nozzles. A smoothly curved flap was attached to the trailing edge of the simulated wing to allow an evaluation of the static turning characteristics of the nozzle arrangement. Forward-speed effects on the jet turning characteristics of the QCSEE nozzles were evaluated by mounting a single engine on a semispan wing designed to be representative of a four-engine STOL transport configuration.

  10. Jet noise modification by the 'whistler nozzle'

    NASA Technical Reports Server (NTRS)

    Hasan, M. A. Z.; Islam, O.; Hussain, A. K. M. F.

    1984-01-01

    The farfield noise characteristics of a subsonic whistler nozzle jet are measured as a function of Mach number (0.25, 0.37, and, 0.51), emission angle, and excitation mode. It is shown that a whistler nozzle has greater total and broadband acoustic power than an excited contraction nozzle; and that the intensity of far-field noise is a function of emission angle, Mach number, and whistler excitation stage. The whistler nozzle excitation produces broadband noise amplification with constant spectral shape; the broadband noise amplification (without associated whistler tones and harmonics) increases omnidirectionally with emission angle at all Mach numbers; and the broadband amplification factor decreases as Mach number and emission angle increase. Finally the whistler nozzle is described as a very efficient but inexpensive siren with applications in not only jet excitation but also acoustics.

  11. Comparative investigation of multiplane thrust vectoring nozzles

    NASA Technical Reports Server (NTRS)

    Capone, F.; Smereczniak, P.; Spetnagel, D.; Thayer, E.

    1992-01-01

    The inflight aerodynamic performance of multiplane vectoring nozzles is critical to development of advanced aircraft and flight control systems utilizing thrust vectoring. To investigate vectoring nozzle performance, subscale models of two second-generation thrust vectoring nozzle concepts currently under development for advanced fighters were integrated into an axisymmetric test pod. Installed drag and vectoring performance characteristics of both concepts were experimentally determined in wind tunnel testing. CFD analyses were conducted to understand the impact of internal flow turning on thrust vectoring characteristics. Both nozzles exhibited drag comparable with current nonvectoring axisymmetric nozzles. During vectored-thrust operations, forces produced by external flow effects amounted to about 25 percent of the total force measured.

  12. Exhaust Nozzle Plume and Shock Wave Interaction

    NASA Technical Reports Server (NTRS)

    Castner, Raymond S.; Elmiligui, Alaa; Cliff, Susan

    2013-01-01

    Fundamental research for sonic boom reduction is needed to quantify the interaction of shock waves generated from the aircraft wing or tail surfaces with the exhaust plume. Both the nozzle exhaust plume shape and the tail shock shape may be affected by an interaction that may alter the vehicle sonic boom signature. The plume and shock interaction was studied using Computational Fluid Dynamics simulation on two types of convergent-divergent nozzles and a simple wedge shock generator. The nozzle plume effects on the lower wedge compression region are evaluated for two- and three-dimensional nozzle plumes. Results show that the compression from the wedge deflects the nozzle plume and shocks form on the deflected lower plume boundary. The sonic boom pressure signature of the wedge is modified by the presence of the plume, and the computational predictions show significant (8 to 15 percent) changes in shock amplitude.

  13. Unconventional nozzle tradeoff study. [space tug propulsion

    NASA Technical Reports Server (NTRS)

    Obrien, C. J.

    1979-01-01

    Plug cluster engine design, performance, weight, envelope, operational characteristics, development cost, and payload capability, were evaluated and comparisons were made with other space tug engine candidates using oxygen/hydrogen propellants. Parametric performance data were generated for existing developed or high technology thrust chambers clustered around a plug nozzle of very large diameter. The uncertainties in the performance prediction of plug cluster engines with large gaps between the modules (thrust chambers) were evaluated. The major uncertainty involves, the aerodynamics of the flow from discrete nozzles, and the lack of this flow to achieve the pressure ratio corresponding to the defined area ratio for a plug cluster. This uncertainty was reduced through a cluster design that consists of a plug contour that is formed from the cluster of high area ratio bell nozzles that have been scarfed. Light-weight, high area ratio, bell nozzles were achieved through the use of AGCarb (carbon-carbon cloth) nozzle extensions.

  14. Flows in a free expansion nozzle

    NASA Astrophysics Data System (ADS)

    Hampel, Klaus

    1990-03-01

    The future transport systems of space travel will carry their load in space, according to aerothermodynamics. The advantages of such systems compared to missiles come from the notably bigger payloads, the launching site flexibility, the better temporary availability, and the re-use ability. Such a system called SAENGER is being discussed in Germany. The propulsion is the central problem of the system. The quality of engine inlet and the expansion nozzle are of decisive importance for the practibility of the project. Several fundementally different concepts, whose efficiency has to be determined, were discussed for the expansion nozzle. Two different nozzle concepts are compared: the plain nozzle and the rotation symmetrical plug nozzle. The two dimensional and two dimensional symmetrical flow fields must be calculated with the Euler and Navier-Stokes processes.

  15. A numerical procedure for the parametric optimization of three dimensional scramjet nozzles

    NASA Technical Reports Server (NTRS)

    Dash, S.; Delguidice, P.; Kalben, P.

    1973-01-01

    A numerical procedure permitting the rapid determination of the internal performance of a class of scramjet nozzle configurations is presented. The approach developed is based on the construction of quasi two dimensional simple wave networks, where lateral expansion effects are incorporated by one dimensional approximations. A numerical procedure following this approach has has been developed and results obtained are highly comparable to those obtained employing a characteristic procedure. The numerical program developed permits the parametric variation of cowl length, turning angles on the cowl and vehicle undersurface and lateral expansion and is subject to fixed constraints such as the vehicle length and nozzle exit height. The program requires uniform initial conditions at the burner exit station and yields the location of all predominant wave zones, accounting for lateral expansion effects. In addition, the program yields the detailed pressure distribution on the cowl and vehicle undersurface and calculates the nozzle thrust, lift and pitching moment.

  16. Computational prediction of isolated performance of an axisymmetric nozzle at Mach number 0.90

    NASA Technical Reports Server (NTRS)

    Carlson, John R.

    1994-01-01

    An improved ability to predict external propulsive performance was incorporated into the three-dimensional Navier-Stokes code PAB3D. The improvements are the ability to account for skin friction and external pressure forces. Performance parameters for two axisymmetric supersonic cruise nozzle configurations were calculated to test the improved methodology. Internal and external flow-field regions were computed using a two-equation kappa-epsilon turbulent viscous-stress model. The computed thrust-minus-drag ratios were within 1 percent of the absolute level of experimental data and the trends of data were predicted accurately. The predicted trend of integrated nozzle pressure drag matched the trend of the integrated experimental pressure drag over a range of nozzle pressure ratios, but absolute drag levels were not accurately predicted.

  17. Fluid and structural dynamic design considerations of the HYLIFE nozzle plate

    SciTech Connect

    Pitts, J.H.; Ojalvo, I.U.

    1981-02-01

    The basic concept of the High Yield Lithium Injection Fusion Energy (HYLIFE) reaction chamber involves a falling liquid-metal (lithium) jet array that absorbs 90% of the energy released from inertial confinement fusion reactions. The key element of the chamber that produces the jet array is the nozzle plate. This paper describes the design and analysis of a nozzle plate which can withstand the structural loads and permit the fluid jet array to be reestablished for a 1-Hz fusion reaction frequency. The shape of the nozzle plate and jet array is dictated by considerations of fluid dynamics and neutron-shielding. A vertical jet array, rather than a single annulus, is used because this design enhances fluid momentum interchange and dissipation of the kinetic energy that occurs when the jets disassemble. Less net outward-directed momentum results than with a single liquid annular flow configuration, thus producing lower stresses in the structural components.

  18. Gen 2.0 Mixer/Ejector Nozzle Test at LSAF June 1995 to July 1996

    NASA Technical Reports Server (NTRS)

    Arney, L. D.; Sandquist, D. L.; Forsyth, D. W.; Lidstone, G. L.; Long-Davis, Mary Jo (Technical Monitor)

    2005-01-01

    Testing of the HSCT Generation 2.0 nozzle model hardware was conducted at the Boeing Low Speed Aeroacoustic Facility, LSAF. Concurrent measurements of noise and thrust were made at critical takeoff design conditions for a variety of mixer/ejector model hardware. Design variables such as suppressor area ratio, mixer area ratio, liner type and thickness, ejector length, lobe penetration, and mixer chute shape were tested. Parallel testing was conducted at G.E.'s Cell 41 acoustic free jet facility to augment the LSAF test. The results from the Gen 2.0 testing are being used to help shape the current nozzle baseline configuration and guide the efforts in the upcoming Generation 2.5 and 3.0 nozzle tests. The Gen 2.0 results have been included in the total airplane system studies conducted at MDC and Boeing to provide updated noise and thrust performance estimates.

  19. Effect of delta tabs on mixing and axis switching in jets from asymmetric nozzles

    NASA Technical Reports Server (NTRS)

    Zaman, K. B. M. Q.

    1994-01-01

    The effect of delta tabs on mixing and the phenomenon of axis switching in free air jets from various asymmetric nozzles was studied experimentally. Flow visualization and Pitot probe surveys were carried out with a set of small nozzles (D = 1.47 cm) at a jet Mach number, Mj = 1.63. Hot wire measurements for streamwise vorticity were carried out with larger nozzles (D = 6.35 cm) at Mj = 0.31. Jet mixing with the asymmetric nozzles, as indicated by the mass fluxes downstream, was found to be higher than that produced by a circular nozzle. The circular nozzle with four delta tabs, however, produced fluxes much higher than that produced by a asymmetric nozzles themselves or by most of the tab configurations tried with them. Even higher fluxes could be obtained with only a few cases, e.g., with 3:1 rectangular nozzle with two large delta tabs placed on the narrow edges. In this case, the jet 'fanned out' at a large angle after going through one axis switch. The axis switching could be either stopped or augmented with suitable choice of the tab configurations. Two mechanisms are identified governing the phenomenon. One, as described in Ref. 12 and referred to here as the omega(sub Theta)-induced dynamics, is due to differential induced velocities of different segments of a rolled up azimuthal vortical structure. The other is the omega(sub x)-induced dynamics due to the induced velocities of streamwise vortex pairs in the flow. While the former dynamics are responsible for rapid axis switching in periodically forced jets, the effect of the tabs is governed mainly by the latter. It is inferred that both dynamics are active in a natural asymmetric jet issuing from a nozzle having an upstream contraction. The tendency for axis switching caused by the omega(sub Theta)-induced dynamics is resisted by the omega(sub x)-induced dynamics, leading to a delayed or no switch over in that case. In jets from orifices and in screeching jets, the omega(sub Theta)-induced dynamics

  20. Vortex dynamics in jets from inclined nozzles

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; Longmire, E. K.

    1997-03-01

    Experimental tests were performed on round jets exiting inclined nozzles at a Reynolds number of 9000. Both natural jets and jets forced with single frequencies corresponding to StD=0.25, 0.5, 0.75, and 1.0 were examined. In the natural case, the nozzle incline caused a mild increase in the radial spreading in the plane of azimuthal symmetry. The forcing amplified the asymmetric radial spreading by altering the vortex structure. In general, the inclined vortex rings rolled up at an angle slightly smaller than the nozzle incline angle. As the rings moved downstream, they migrated away from the jet centerline and their incline angle increased. Vortex rings generated at StD=0.5 did not pair because that Strouhal number was near the "preferred" mode. For nozzles with slight inclines, forcing at larger Strouhal numbers led to pairing near x/D=2 in order to achieve the "preferred" mode. For nozzles with larger inclines, the vortex cores broke down before pairing could occur. Forcing at a lower Strouhal number (StD=0.25) yielded ring formation at StD=0.5 and subsequent pairing. Increasing the incline angle moved the pairing location closer to the nozzle lip. Also, the pairing process was found to depend on the nozzle incline angle.

  1. Transient, hypervelocity flow in an axisymmetric nozzle

    NASA Technical Reports Server (NTRS)

    Jacobs, P. A.

    1991-01-01

    The performance of an axisymmetric nozzle was examined which was designed to produce uniform, parallel flow with a nominal Mach number of 8. A free-piston driven shock tube was used to supply the nozzle with high-temperature, high-pressure test gas. Performance was assessed by measuring Pitot pressures across the exit plane of the nozzle and, over the range of operating conditions examined, the nozzle produced satisfactory test flows. However, there were flow disturbances that persisted for significant times after flow initiation. The detailed starting process of the nozzle was also investigated by performing numerical simulations at several nominal test conditions. The classical description of the starting process, based on a quasi-one-dimensional model, provided a reasonable approximation and was used to demonstrate that the starting process could consume a significant fraction of the otherwise usable test gas. This was especially important at high operating enthalpies where nozzle supply conditions were maintained for shorter times. Multidimensional simulations illustrated a mechanism by which the starting process in the actual nozzle could take longer than that predicted by the quasi-one-dimensional analysis. However, the cause of the persistent disturbances observed in the experimental calibration was not identified.

  2. Jet noise suppression by porous plug nozzles

    NASA Technical Reports Server (NTRS)

    Bauer, A. B.; Kibens, V.; Wlezien, R. W.

    1982-01-01

    Jet noise suppression data presented earlier by Maestrello for porous plug nozzles were supplemented by the testing of a family of nozzles having an equivalent throat diameter of 11.77 cm. Two circular reference nozzles and eight plug nozzles having radius ratios of either 0.53 or 0.80 were tested at total pressure ratios of 1.60 to 4.00. Data were taken both with and without a forward motion or coannular flow jet, and some tests were made with a heated jet. Jet thrust was measured. The data were analyzed to show the effects of suppressor geometry on nozzle propulsive efficiency and jet noise. Aerodynamic testing of the nozzles was carried out in order to study the physical features that lead to the noise suppression. The aerodynamic flow phenomena were examined by the use of high speed shadowgraph cinematography, still shadowgraphs, extensive static pressure probe measurements, and two component laser Doppler velocimeter studies. The different measurement techniques correlated well with each other and demonstrated that the porous plug changes the shock cell structure of a standard nozzle into a series of smaller, periodic cell structures without strong shock waves. These structures become smaller in dimension and have reduced pressure variations as either the plug diameter or the porosity is increased, changes that also reduce the jet noise and decrease thrust efficiency.

  3. Fastrac Nozzle Design, Performance and Development

    NASA Technical Reports Server (NTRS)

    Peters, Warren; Rogers, Pat; Lawrence, Tim; Davis, Darrell; DAgostino, Mark; Brown, Andy

    2000-01-01

    With the goal of lowering the cost of payload to orbit, NASA/MSFC (Marshall Space Flight Center) researched ways to decrease the complexity and cost of an engine system and its components for a small two-stage booster vehicle. The composite nozzle for this Fastrac Engine was designed, built and tested by MSFC with fabrication support and engineering from Thiokol-SEHO (Science and Engineering Huntsville Operation). The Fastrac nozzle uses materials, fabrication processes and design features that are inexpensive, simple and easily manufactured. As the low cost nozzle (and injector) design matured through the subscale tests and into full scale hot fire testing, X-34 chose the Fastrac engine for the propulsion plant for the X-34. Modifications were made to nozzle design in order to meet the new flight requirements. The nozzle design has evolved through subscale testing and manufacturing demonstrations to full CFD (Computational Fluid Dynamics), thermal, thermomechanical and dynamic analysis and the required component and engine system tests to validate the design. The Fastrac nozzle is now in final development hot fire testing and has successfully accumulated 66 hot fire tests and 1804 seconds on 18 different nozzles.

  4. Scramjet nozzle design and analysis as applied to a highly integrated hypersonic research airplane

    NASA Technical Reports Server (NTRS)

    Small, W. J.; Weidner, J. P.; Johnston, P. J.

    1974-01-01

    The configuration and performance of the propulsion system for the hypersonic research vehicle are discussed. A study of the interactions between propulsion and aerodynamics of the highly integrated vehicle was conducted. The hypersonic research vehicle is configured to test the technology of structural and thermal protection systems concepts and the operation of the propulsion system under true flight conditions for most of the hypersonic flight regime. The subjects considered are: (1) research vehicle and scramjet engine configurations to determine fundamental engine sizing constraints, (2) analytical methods for computing airframe and propulsion system components, and (3) characteristics of a candidate nozzle to investigate vehicle stability and acceleration performance.

  5. Implicit time-marching solution of the Navier-Stokes equations for thrust reversing and thrust vectoring nozzle flows

    NASA Technical Reports Server (NTRS)

    Imlay, S. T.

    1986-01-01

    An implicit finite volume method is investigated for the solution of the compressible Navier-Stokes equations for flows within thrust reversing and thrust vectoring nozzles. Thrust reversing nozzles typically have sharp corners, and the rapid expansion and large turning angles near these corners are shown to cause unacceptable time step restrictions when conventional approximate factorization methods are used. In this investigation these limitations are overcome by using second-order upwind differencing and line Gauss-Siedel relaxation. This method is implemented with a zonal mesh so that flows through complex nozzle geometries may be efficiently calculated. Results are presented for five nozzle configurations including two with time varying geometries. Three cases are compared with available experimental data and the results are generally acceptable.

  6. Model aerodynamic test results for a refined actuated inlet ejector nozzle at simulated takeoff and cruise conditions

    NASA Technical Reports Server (NTRS)

    Nelson, D. P.

    1983-01-01

    Wind tunnel model tests were conducted to demonstrate the aerodynamic performance improvements of a refined actuated inlet ejector nozzle. Models of approximately one-tenth scale were configured to simulate nozzle operation at takeoff, subsonic cruise, transonic cruise and supersonic cruise. Variations of model components provided a performance evaluation of ejector inlet and exit area, forebody boattail angle and ejector inlet operation in the open and closed mode. Approximately 700 data points were acquired at Mach numbers of 0, 0.36, 0.9, 1.2, and 2.0 for a wide range of nozzle flow conditions. Results show that relative to two ejector nozzles previously tested performance was improved significantly at takeoff and subsonic cruise performance, a C sub f of 0.982, was attained equal to the high performance of the previous tests. The established advanced supersonic transport propulsion study performance goals were met or closely approached at takeoff and supersonic cruise.

  7. Mixing Process in Ejector Nozzles Studied at Lewis' Aero-Acoustic Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The NASA Lewis Research Center has been studying mixing processes in ejector nozzles for its High Speed Research (HSR) Program. This work is directed at finding ways to minimize the noise of a future supersonic airliner. Much of the noise such an airplane would generate would come from the nozzle, where a hot, high-speed jet exits the engine. Several different nozzle configurations were used to produce nozzle systems with different acoustical and aerodynamic characteristics. The acoustical properties were measured by an array of microphones in an anechoic chamber, and the aerodynamics were measured by traditional pressure and temperature instruments as well as by Laser Doppler Velocimetry (LDV), a technique for visualizing the airflow pattern without disturbing it. These measurements were put together and compared for different configurations to examine the relationships between mixing and noise generation. The mixer-ejector nozzle with the installed flow-visualization windows (foreground), the optical equipment and the supporting structure for the Laser Doppler Velocimetry flow visualization (midfield), and the sound-absorbing wedges used to create an anechoic environment for acoustic testing (background) is shown. The High Speed Research Program is a NASA-funded effort, in cooperation with the U.S. aerospace industry, to develop enabling technologies for a future supersonic airliner. One of the technological barriers being addressed is noise generated during near-airport operation. The mixer-ejector nozzle concept is being examined as a way to reduce jet noise while maintaining thrust. Ambient air is mixed with the high-velocity engine exhaust to reduce the jet velocity and hence the noise generated by the jet. The model was designed and built by Pratt & Whitney under NASA contract. The test, completed in June 1995, was conducted in Lewis' Aero-Acoustic Propulsion Laboratory.

  8. Effect of nozzle lateral spacing on afterbody drag and performance of twin-jet afterbody models with convergent-divergent nozzles at Mach numbers up to 2.2

    NASA Technical Reports Server (NTRS)

    Pendergraft, O. C., Jr.; Schmeer, J. W.

    1972-01-01

    Twin-jet afterbody models were investigated by using two balances to measure the thrust-minus-total drag and the afterbody drag, separately, at static conditions and at Mach numbers up to 2.2 for an angle of attack of 0 deg. Hinged-flap convergent-divergent nozzles were tested at subsonic-cruise- and maximum-afterburning-power settings with a high-pressure air system used to provide jet-total-pressure ratios up to 20. Two nozzle lateral spacings were studied, using afterbodies with similar interfairing shapes but with different longitudinal cross-sectional area distributions. Alternate, blunter, interfairings with different shapes for the two spacings, which produced afterbodies having identical cross-sectional area progressions corresponding to an axisymmetric minimum wave-drag configuration, were also tested. The results indicate that the wide-spaced configurations improved the flow field around the nozzles, thereby reducing drag on the cruise nozzles; however, the increased surface and projected cross-sectional areas caused an increase in afterbody drag. Except for a slight advantage with cruise nozzles at subsonic speeds, the wide-spaced configurations had the higher total drag at all other test conditions.

  9. Gas exhaust nozzle for ARC furnaces

    SciTech Connect

    Buhler, K.

    1984-10-09

    Arc furnace has a furnace shell, a furnace lid with lid ring and a lid lifting and swivelling means as well as a lid opening in the furnace lid for exhausting the flue gas from the interior of the furnace and a flue gas exhaust nozzle for removing the flue gases above the lid opening, the nozzle being supported on the furnace lid ring. By means of this design feature as well as a guide arrangement and a locking means the flue gas exhaust nozzle can be completely integrated into the operating steps of the arc furnace in a simple and economical fashion.

  10. Turbine nozzle stage having thermocouple guide tube

    DOEpatents

    Schotsch, Margaret Jones; Kirkpatrick, Francis Lawrence; Lapine, Eric Michael

    2002-01-01

    A guide tube is fixed adjacent opposite ends in outer and inner covers of a nozzle stage segment. The guide tube is serpentine in shape between the outer and inner covers and extends through a nozzle vane. An insert is disposed in the nozzle vane and has apertures to accommodate serpentine portions of the guide tube. Cooling steam is also supplied through chambers of the insert on opposite sides of a central insert chamber containing the guide tube. The opposite ends of the guide tube are fixed to sleeves, in turn fixed to the outer and inner covers.

  11. Flow-structure interaction effects on a jet emanating from a flexible nozzle

    PubMed Central

    Murugappan, S.; Gutmark, E. J.; Lakhamraju, R. R.; Khosla, S.

    2008-01-01

    In recent years, a wide variety of applications have been found for the use of pulsed jets in the area of flow control. The goal of the current study was to identify the flow field and mixing characteristics associated with an incompressible elongated jet emitted from a flexible nozzle. The shape of the nozzle was that of a high aspect ratio jet deforming from a fully opened to a completely closed configuration. The jet was characterized by a pulsatile flow that was self-excited by the motion of the flexible tube. The frequency of excitation was found to be between 150 and 175 Hz and the Strouhal number (nondimensional frequency) varied from 0.17 to 0.45. The jet flow was dominated by vortices that were shed from the nozzle with an axis parallel to the major axis. The vortices in the near field were quasi-two-dimensional so that measurements performed at the center plane represented the dynamics of the entire vortex. The nozzle excited two different modes depending on the tension applied to the flexible nozzle and the volumetric flow through it. The first was a flapping mode, which was associated with alternate shedding of vortices. This caused strong steering of the jet to one side or the other. The second mode was a symmetric mode that was associated with the formation of counter-rotating vortex pairs. Turbulence and jet spread in the measured planes were much larger in the first mode than the second one. PMID:19547723

  12. Flight effects on the aerodynamic and acoustic characteristics of inverted profile coannular nozzles

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Packman, A. B.

    1978-01-01

    The effect of forward flight on the jet noise of coannular exhaust nozzles, suitable for Variable Stream Control Engines (VSCE), was investigated in a series of wind tunnel tests. The primary stream properties were maintained constant at 300 mps and 394 K. A total of 230 acoustic data points was obtained. Force measurement tests using an unheated air supply covered the same range of tunnel speeds and nozzle pressure ratios on each of the nozzle configurations. A total of 80 points was taken. The coannular nozzle OASPL and PNL noise reductions observed statically relative to synthesized values were basically retained under simulated flight conditions. The effect of fan to primary stream area ratio on flight effects was minor. At take-off speed, the peak jet noise for a VSCE was estimated to be over 6 PNdB lower than the static noise level. High static thrust coefficients were obtained for the basic coannular nozzles, with a decay of 0.75 percent at take-off speeds.

  13. Flow-structure interaction effects on a jet emanating from a flexible nozzle

    NASA Astrophysics Data System (ADS)

    Murugappan, S.; Gutmark, E. J.; Lakhamraju, R. R.; Khosla, S.

    2008-11-01

    In recent years, a wide variety of applications have been found for the use of pulsed jets in the area of flow control. The goal of the current study was to identify the flow field and mixing characteristics associated with an incompressible elongated jet emitted from a flexible nozzle. The shape of the nozzle was that of a high aspect ratio jet deforming from a fully opened to a completely closed configuration. The jet was characterized by a pulsatile flow that was self-excited by the motion of the flexible tube. The frequency of excitation was found to be between 150 and 175 Hz and the Strouhal number (nondimensional frequency) varied from 0.17 to 0.45. The jet flow was dominated by vortices that were shed from the nozzle with an axis parallel to the major axis. The vortices in the near field were quasi-two-dimensional so that measurements performed at the center plane represented the dynamics of the entire vortex. The nozzle excited two different modes depending on the tension applied to the flexible nozzle and the volumetric flow through it. The first was a flapping mode, which was associated with alternate shedding of vortices. This caused strong steering of the jet to one side or the other. The second mode was a symmetric mode that was associated with the formation of counter-rotating vortex pairs. Turbulence and jet spread in the measured planes were much larger in the first mode than the second one.

  14. Experimental and analytical study of close-coupled ventral nozzles for ASTOVL aircraft

    NASA Technical Reports Server (NTRS)

    Mcardle, Jack G.; Smith, C. Frederic

    1990-01-01

    Flow in a generic ventral nozzle system was studied experimentally and analytically with a block version of the PARC3D computational fluid dynamics program (a full Navier-Stokes equation solver) in order to evaluate the program's ability to predict system performance and internal flow patterns. For the experimental work a one-third-size model tailpipe with a single large rectangular ventral nozzle mounted normal to the tailpipe axis was tested with unheated air at steady-state pressure ratios up to 4.0. The end of the tailpipe was closed to simulate a blocked exhaust nozzle. Measurements showed about 5 1/2 percent flow-turning loss, reasonable nozzle performance coefficients, and a significant aftward axial component of thrust due to flow turning loss, reasonable nozzle performance coefficients, and a significant aftward axial component of thrust due to flow turning more than 90 deg. Flow behavior into and through the ventral duct is discussed and illustrated with paint streak flow visualization photographs. For the analytical work the same ventral system configuration was modeled with two computational grids to evaluate the effect of grid density. Both grids gave good results. The finer-grid solution produced more detailed flow patterns and predicted performance parameters, such as thrust and discharge coefficient, within 1 percent of the measured values. PARC3D flow visualization images are shown for comparison with the paint streak photographs. Modeling and computational issues encountered in the analytical work are discussed.

  15. A Parametric Study of a Plug Nozzle, Using the Liquid Propellant Program (LPP) Code

    NASA Technical Reports Server (NTRS)

    Dunn, Stuart S.; Coats, Douglas E.

    1996-01-01

    The Liquid Propellant Program (LPP) computer code is a super-set of the industry standard Two Dimensional Kinetics (TDK) computer code. The TDK code uses a two dimensional method of characteristics solution with fully coupled finite rate kinetics for axially symmetric nozzles. The chemical reactions are modeled with a generalized reaction package that include three dimensional body efficiencies and four reaction rate forms. The code performs optional solutions for frozen or equilibrium flow. TDK evaluates discrete shocks, both attached or induced. The Transonic module models variable mixture ratio profiles from the combustion chamber injector. The Mass Addition Boundary Layer module (MABL) calculates the boundary parameters with the same chemistry options, and includes transpiration or tangential slot injection of gas at the wall. The LPP upgrades include: planar nozzle, scarfed nozzles, plug nozzles, and scramjet nozzle configurations. The code evaluates both upper and lower wall flow simulation, and includes the interaction with the external flow. The MABL module evaluates equilibrium radiation heat transfer for both upper and lower walls. In addition, LPP code models combustion effects due to injector inefficiencies with the Spray Combustion Analysis Program (SCAP) module. The LPP package provides extensive post plotting capabilities for flow visualization. The LPP is sufficiently fast and robust to provide performance predictions for extensive parametric studies and sufficiently accurate to provide flow field and performance solutions for detailed studies.

  16. Internal performance of a nonaxisymmetric nozzle with a rotating upper flap and a center-pivoted lower flap

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Leavitt, Laurence D.; Re, Richard J.

    1993-01-01

    An investigation was conducted at wind-off conditions in the static-test facility of the Langley 16-Foot Transonic Tunnel to determine the internal performance characteristics of a single expansion-ramp nozzle with thrust-vectoring capability to 105 degrees. Thrust vectoring was accomplished by the downward rotation of an upper flap with adaptive capability for internal contouring and a corresponding rotation of a center-pivoted lower flap. The static internal performance of configurations with pitch thrust-vector angles of 0 degrees, 60 degrees, and 105 degrees each with two throat areas, was investigated. The nozzle pressure ratio was varied from 1.5 to approximately 8.0 (5.0 for the maximum throat area configurations). Results of this study indicated that the nozzle configuration of the present investigation, when vectored, provided excellent flow-turning capability with relatively high levels of internal performance. In all cases, the thrust vector angle was a function of the nozzle pressure ratio. This result is expected because the flow is bounded by a single expansion surface on both vectored- and unvectored-nozzle geometries.

  17. Subscale solid motor nozzle tests, phase 4 and nozzle materials screening and thermal characterization, phase 5

    NASA Technical Reports Server (NTRS)

    Arnold, J.; Dodson, J.; Laub, B.

    1979-01-01

    Subscale solid motor nozzles containing a baseline material or low cost materials to be considered as potential replacements for the baseline material are designed and tested. Data are presented from tests of four identically designed 2.5 inch throat diameter nozzles and one 7 inch throat diameter nozzle. The screening of new candidate low cost materials, as well as their thermophysical and thermochemical characterization is also discussed.

  18. Nuclear thermal rocket nozzle testing and evaluation program

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth O.; Kacynski, Kenneth J.

    1993-01-01

    Performance characteristics of the Nuclear Thermal Rocket can be enhanced through the use of unconventional nozzles as part of the propulsion system. The Nuclear Thermal Rocket nozzle testing and evaluation program being conducted at the NASA Lewis is outlined and the advantages of a plug nozzle are described. A facility description, experimental designs and schematics are given. Results of pretest performance analyses show that high nozzle performance can be attained despite substantial nozzle length reduction through the use of plug nozzles as compared to a convergent-divergent nozzle. Pretest measurement uncertainty analyses indicate that specific impulse values are expected to be within + or - 1.17 pct.

  19. Method for Forming MEMS-Based Spinning Nozzle

    NASA Technical Reports Server (NTRS)

    Okojie, Robert S. (Inventor)

    2004-01-01

    A nozzle body and assembly for delivering atomized fuel to a combustion chamber. The nozzle body is rotatably mounted onto a substrate. One or more curvilinear fuel delivery channels are in flow communication with an internal fuel distribution cavity formed in the nozzle body. Passage of pressurized fuel through the nozzle body causes the nozzle body to rotate. Components of the nozzle assembly are formed of silicon carbide having surfaces etched by deep reactive ion etching utilizing MEMS technology. A fuel premix chamber is carried on the substrate in flow communication with a supply passage in the nozzle body.

  20. Method of cooling gas only nozzle fuel tip

    DOEpatents

    Bechtel, William Theodore; Fitts, David Orus; DeLeonardo, Guy Wayne

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  1. Exhaust Nozzle Plume Effects on Sonic Boom Test Results for Vectored Nozzles

    NASA Technical Reports Server (NTRS)

    Castner, Raymond

    2012-01-01

    Reducing or eliminating the operational restrictions of supersonic aircraft over populated areas has led to extensive research at NASA. Restrictions were due to the disturbance of the sonic boom, caused by the coalescence of shock waves formed off the aircraft. Recent work has been performed to reduce the magnitude of the sonic boom N-wave generated by airplane components with a focus on shock waves caused by the exhaust nozzle plume. Previous Computational Fluid Dynamics (CFD) analysis showed how the shock wave formed at the nozzle lip interacts with the nozzle boat-tail expansion wave. An experiment was conducted in the 1- by 1-foot Supersonic Wind Tunnel (SWT) at the NASA Glenn Research Center. Results show how the shock generated at the nozzle lip affects the near field pressure signature, and thereby the potential sonic boom contribution for a nozzle at vector angles from 3 to 8 . The experiment was based on the NASA F-15 nozzle used in the Lift and Nozzle Change Effects on Tail Shock experiment, which possessed a large external boat-tail angle. In this case, the large boat-tail angle caused a dramatic expansion, which dominated the near field pressure signature. The impact of nozzle vector angle and nozzle pressure ratio are summarized.

  2. Wind Tunnel Model Design for the Study of Plume Effects on Sonic Boom for Isolated Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Castner, Raynold S.

    2010-01-01

    A low cost test capability was developed at the NASA Glenn Research Center 1- by 1-Foot Supersonic Wind Tunnel (SWT), with a goal to reduce the disturbance caused by supersonic aircraft flight over populated areas. This work focused on the shock wave structure caused by the exhaust nozzle plume. Analysis and design was performed on a new rig to test exhaust nozzle plume effects on sonic boom signature. Test capability included a baseline nozzle test article and a wind tunnel model consisting of a strut, a nosecone and an upper plenum. Analysis was performed on the external and internal aerodynamic configuration, including the shock reflections from the wind tunnel walls caused by the presence of the model nosecone. This wind tunnel model was designed to operate from Mach 1.4 to Mach 3.0 with nozzle pressure ratios from 6 to 12 and altitudes from 30,000 ft (4.36 psia) to 50,000 ft (1.68 psia). The model design was based on a 1 in. outer diameter, was 9 in. in overall length, and was mounted in the wind tunnel on a 3/8 in. wide support strut. For test conditions at 50,000 ft the strut was built to supply 90 psia of pressure, and to achieve 20 psia at the nozzle inlet with a maximum nozzle pressure of 52 psia. Instrumentation was developed to measure nozzle pressure ratio, and an external static pressure probe was designed to survey near field static pressure profiles at one nozzle diameter above the rig centerline. Model layout placed test nozzles between two transparent sidewalls in the 1 1 SWT for Schlieren photography and comparison to CFD analysis.

  3. Wind Tunnel Model Design for the Study of Plume Effects on Sonic Boom for Isolated Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Castner, Raymond S.

    2009-01-01

    A low cost test capability was developed at the NASA Glenn Research Center 1- by 1-Foot Supersonic Wind Tunnel (SWT), with a goal to reduce the disturbance caused by supersonic aircraft flight over populated areas. This work focused on the shock wave structure caused by the exhaust nozzle plume. Analysis and design was performed on a new rig to test exhaust nozzle plume effects on sonic boom signature. Test capability included a baseline nozzle test article and a wind tunnel model consisting of a strut, a nose cone and an upper plenum. Analysis was performed on the external and internal aerodynamic configuration, including the shock reflections from the wind tunnel walls caused by the presence of the model nosecone. This wind tunnel model was designed to operate from Mach 1.4 to Mach 3.0 with nozzle pressure ratios from 6 to 12 and altitudes from 30,000 ft (4.36 psia) to 50,000 ft (1.68 psia). The model design was based on a 1 in. outer diameter, was 9 in. in overall length, and was mounted in the wind tunnel on a 3/8 in. wide support strut. For test conditions at 50,000 ft the strut was built to supply 90 psia of pressure, and to achieve 20 psia at the nozzle inlet with a maximum nozzle pressure of 52 psia. Instrumentation was developed to measure nozzle pressure ratio, and an external static pressure probe was designed to survey near field static pressure profiles at one nozzle diameter above the rig centerline. Model layout placed test nozzles between two transparent sidewalls in the 1x1 SWT for Schlieren photography and comparison to CFD analysis.

  4. Submerged Entry Nozzles that Resist Clogging

    SciTech Connect

    2001-04-01

    Development Of Submerged Entry Nozzles (SENs) Can Incrase Yields, Improve Product Quality, And Increase Productivity In Continuous Casting Of Steel, A Process Used For The Production Of 95% Of Steel In The U.S.

  5. Natural gas flow through critical nozzles

    NASA Technical Reports Server (NTRS)

    Johnson, R. C.

    1969-01-01

    Empirical method for calculating both the mass flow rate and upstream volume flow rate through critical flow nozzles is determined. Method requires knowledge of the composition of natural gas, and of the upstream pressure and temperature.

  6. A quick accurate model of nozzle backflow

    NASA Technical Reports Server (NTRS)

    Kuharski, R. A.

    1991-01-01

    Backflow from nozzles is a major source of contamination on spacecraft. If the craft contains any exposed high voltages, the neutral density produced by the nozzles in the vicinity of the craft needs to be known in order to assess the possibility of Paschen breakdown or the probability of sheath ionization around a region of the craft that collects electrons for the plasma. A model for backflow has been developed for incorporation into the Environment-Power System Analysis Tool (EPSAT) which quickly estimates both the magnitude of the backflow and the species makeup of the flow. By combining the backflow model with the Simons (1972) model for continuum flow it is possible to quickly estimate the density of each species from a nozzle at any position in space. The model requires only a few physical parameters of the nozzle and the gas as inputs and is therefore ideal for engineering applications.

  7. Experiments and Analyses of Distributed Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Kinzie, Kevin W.; Schein, David B.; Solomon, W. David, Jr.

    2002-01-01

    Experimental and analytical aeroacoustic properties of several distributed exhaust nozzle (DEN) designs are presented. Significant differences between the designs are observed and correlated back to Computational Fluid Dynamics (CFD) flowfield predictions. Up to 20 dB of noise reduction on a spectral basis and 10 dB on an overall sound pressure level basis are demonstrated from the DEN designs compared to a round reference nozzle. The most successful DEN designs acoustically show a predicted thrust loss of approximately 10% compared to the reference nozzle. Characteristics of the individual mini-jet nozzles that comprise the DEN such as jet-jet shielding and coalescence are shown to play a major role in the noise signature.

  8. Low thermal stress ceramic turbine nozzle

    DOEpatents

    Glezer, Boris; Bagheri, Hamid; Fierstein, Aaron R.

    1996-01-01

    A turbine nozzle vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and being attached to conventional metallic components. The metallic components having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes an outer shroud and an inner shroud having a plurality of vanes therebetween. Each of the plurality of vanes have a device for heating and cooling a portion of each of the plurality of vanes. Furthermore, the inner shroud has a plurality of bosses attached thereto. A cylindrical member has a plurality of grooves formed therein and each of the plurality of bosses are positioned in corresponding ones of the plurality of grooves. The turbine nozzle vane assembly provides an economical, reliable and effective ceramic component having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the other component.

  9. Lift Fan Nozzle for Joint Strike Fighter Tested in NASA Lewis' Powered Lift Rig

    NASA Technical Reports Server (NTRS)

    Lam, David W.

    1998-01-01

    Under a nonreimbursable space act agreement between the NASA Lewis Research Center and the Allison Advanced Development Company, Allison tested a lift fan nozzle in Lewis' Powered Lift Rig. This test was in support of the Joint Strike Fighter program (formerly the Joint Advanced Strike Technology) sponsored by the Department of Defense, which will develop and field an affordable, multirole, next-generation, strike fighter aircraft for the Navy, Air Force, Marine Corps, and foreign allies. Allison, along with Pratt & Whitney Company, is part of the Lockheed Martin Corporation team that is scheduled to build a concept demonstrator aircraft by fiscal year 2001. The test was initiated in April and successfully completed in mid-July of 1997. Allison supplied a one-third-scale model of the lift fan nozzle, and Lewis provided the facility and the necessary support team. Various configurations, including pitching vectored angles ranging from 15deg forward to 60deg backward, were tested over a range of nozzle pressure ratios. Nozzle flow rates, thrust, and static pressures were measured for each of the configurations. Results from the test met the design requirements for the Joint Strike Fighter program and were in agreement with Allison's internal computational fluid dynamics (CFD) analyses. Data obtained from this test will also be used in the full-scale design of the lift fan system.

  10. Flight and wind tunnel test results of the mechanical jet noise suppressor nozzle

    NASA Astrophysics Data System (ADS)

    Fitzsimmons, R. D.; McKinnon, R. A.; Johnson, E. S.; Brooks, J. R.

    1980-01-01

    Comprehensive acoustic and propulsion data are presented, based on flight and wind tunnel tests, of a mechanical jet noise suppressor designed to satisfy the requirements of an advanced supersonic transport (AST) under study by the McDonnell Douglas Corporation. The flight program was conducted jointly by MDC, Rolls-Royce Ltd., and the British Aerospace Corporation, using an HS-125 aircraft modified to accept an upgraded RR Viper 601 engine with conical reference and mechanical suppressor nozzles and an acoustically treated ejector. The nacelle, engine and nozzle configurations from the HS-125 were also tested in one of NASA's wind tunnels to obtain thrust performance at forward velocity and acoustic data. The acoustic flight test data, when scaled to an AST engine nozzle size and projected to a typical sideline distance, indicate reduction in effective perceived noise level of 16 EPNdB at the takeoff power setting. It is estimated that the in-flight thrust loss for a typical AST suppressor/ejector nozzle configuration (37.5 inch equivalent diameter) would be 5.4 percent at takeoff power settings and 6.6 percent at cutback power settings.

  11. Exhaust Nozzles for Supersonic Flight with Turbojet Engines

    NASA Technical Reports Server (NTRS)

    Shillito, Thomas B.; Hearth, Donald P.; Cortright, Edgar M.

    1956-01-01

    Good internal performance over a wide range of flight conditions can be obtained with either a plug nozzle or a variable ejector nozzle that can provide a divergent shroud at high pressure ratios. For both the ejector and the plug nozzle, external flow can sometimes cause serious drag losses and, for some plug-nozzle installations, external flow can cause serious internal performance losses. Plug-nozzle cooling and design of the secondary-air-flow systems for ejectors were also considered .

  12. Design of a new type vapor recovery system nozzle

    NASA Astrophysics Data System (ADS)

    Fu, S. H.; Cao, G. J.; Zhang, D. S.

    2016-05-01

    To settle the problem of low-efficiency recovery for Vapor recovery system nozzle, this paper advances a purely mechanical structure of the self-sealing refueling VRS nozzle. The structure, operating principle and controlled process of the nozzle is given. And an application of the nozzle is discussed. All indicated that the nozzle has a reasonable structure, can fuel and vapor recovery simultaneous start and stop. And thus improve the recovery efficiency and reduce oil leakage.

  13. Aircraft Engine Exhaust Nozzle System for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H. (Inventor); Czech, Michael J. (Inventor); Elkoby, Ronen (Inventor)

    2014-01-01

    The aircraft exhaust engine nozzle system includes a fan nozzle to receive a fan flow from a fan disposed adjacent to an engine disposed above an airframe surface of the aircraft, a core nozzle disposed within the fan nozzle and receiving an engine core flow, and a pylon structure connected to the core nozzle and structurally attached with the airframe surface to secure the engine to the aircraft.

  14. Two dimensional wedge/translating shroud nozzle

    NASA Technical Reports Server (NTRS)

    Maiden, D. L. (Inventor)

    1978-01-01

    A jet propulsion exhaust nozzle is reported for multi-engine installations which produces high internal/external, thrust-minus-drag, performance for transonic cruise or transonic acceleration as well as improved performance at subsonic and supersonic speeds. A two dimensional wedge/translating shroud provides the variable nozzle exit geometry needed to achieve high engine performance over a wide range of throttle power settings.

  15. Aeroacoustic Resonance with Convergent-Divergent Nozzles

    NASA Technical Reports Server (NTRS)

    Zaman, K. B. M. Q.; Dahl, M. D.

    1999-01-01

    Convergent-divergent nozzles, when run at off-design conditions, often undergo flow resonance accompanied by the emission of a tone. Apart from screech occurring at higher operating pressures, resonance is also common at lower Mach numbers near transonic as well as subsonic conditions. With data from six nozzles of different size and design Mach number, the present paper documents the characteristics of the latter phenomenon that is morphologically quite different from conventional screech. The resonance is due to a feedback loop internal to the nozzle and is apparently driven by unsteady laminar boundary layer separation near the throat of the nozzle. Appropriate boundary layer tripping prior to the throat is found to eliminate or alter most of the tones. The Helmholtz number of the resonance, based on the throat-to-exit length, is found to attain a value of approximately 0.15 at M(sub j)=1 for all nozzles. However, its variation with M(sub j) may be different and depend on the nozzle geometry. With nozzles having larger throat-to-exit angle of divergence, the frequency is found to increase, in some cases having stage jumps to lower frequencies, with increasing operating pressure. With nozzles having smaller angle of divergence, the frequency variation exhibits an increase followed by a decrease involving one prominent stage occurring around transonic (M(sub j)= 1) condition. While the mechanisms remain far from completely clear, a model involving downstream propagating aerodynamic disturbance together with acoustic feedback explains the overall frequency characteristics for most cases.

  16. CT Scan of NASA Booster Nozzle

    SciTech Connect

    Schneberk, D; Perry, R; Thompson, R

    2004-07-27

    We scanned a Booster Nozzle for NASA with our 9 meV LINAC, AmSi panel scanner. Three scans were performed using different filtering schemes and different positions of the nozzle. The results of the scan presented here are taken from the scan which provided the best contrast and lowest noise of the three. Our inspection data shows a number of indications of voids in the outer coating of rubber/carbon. The voids are mostly on the side of the nozzle, but a few small voids are present at the ends of the nozzle. We saw no large voids in the adhesive layer between the Aluminum and the inner layer of carbon. This 3D inspection data did show some variation in the size of the adhesive layer, but none of the indications were larger than 3 pixels in extent (21 mils). We have developed a variety of contour estimation and extraction techniques for inspecting small spaces between layers. These tools might work directly on un-sectioned nozzles since the circular contours will fit with our tools a little better. Consequently, it would be useful to scan a full nozzle to ensure there are no untoward degradations in data quality, and to see if our tools would work to extract the adhesive layer.

  17. Jet-diffuser Ejector - Attached Nozzle Design

    NASA Technical Reports Server (NTRS)

    Alperin, M.; Wu, J. J.

    1980-01-01

    Attached primary nozzles were developed to replace the detached nozzles of jet-diffuser ejectors. Slotted primary nozzles located at the inlet lip and injecting fluid normal to the thrust axis, and rotating the fluid into the thrust direction using the Coanda Effect were investigated. Experiments indicated excessive skin friction or momentum cancellation due to impingement of opposing jets resulted in performance degradation. This indicated a desirability for location and orientation of the injection point at positions removed from the immediate vicinity of the inlet surface, and at an acute angle with respect to the thrust axis. Various nozzle designs were tested over a range of positions and orientations. The problems of aircraft integration of the ejector, and internal and external nozzle losses were also considered and a geometry for the attached nozzles was selected. The effect of leaks, protrusions, and asymmetries in the ejector surfaces was examined. The results indicated a relative insensitivity to all surface irregularities, except for large protrusions at the throat of the ejector.

  18. Acoustic Measurements of Rectangular Nozzles With Bevel

    NASA Technical Reports Server (NTRS)

    Bridges, James E.

    2012-01-01

    A series of convergent rectangular nozzles of aspect ratios 2:1, 4:1, and 8:1 were constructed with uniform exit velocity profiles. Additional nozzles were constructed that extended the wide lip on one side of these nozzles to form beveled nozzles. Far-field acoustic measurements were made and analyzed, and the results presented. The impact of aspect ratio on jet noise was similar to that of enhanced mixing devices: reduction in aft, peak frequency noise with an increase in broadside, high frequency noise. Azimuthally, it was found that rectangular jets produced more noise directed away from their wide sides than from their narrow sides. The azimuthal dependence decreased at aft angles where noise decreased. The effect of temperature, keeping acoustic Mach number constant, was minimal. Since most installations would have the observer on the wide size of the nozzle, the increased high frequency noise has a deleterious impact on the observer. Extending one wide side of the rectangular nozzle, evocative of an aft deck in an installed propulsion system, increased the noise of the jet with increasing length. The impact of both aspect ratio and bevel length were relatively well behaved, allowing a simple bilinear model to be constructed relative to a simple round jet.

  19. Decomposing Solid Micropropulsion Nozzle Performance Issues

    NASA Technical Reports Server (NTRS)

    Reed, Brian

    2003-01-01

    Micropropulsion technology is essential to the success of miniaturized spacecraft and can provide ultra-precise propulsion for small spacecraft. NASA Glenn Research Center has envisioned a micropropulsion concept that utilizes decomposing solid propellants for a valveless, leak-free propulsion system. Among the technical challenges of this decomposing solid micropropulsion concept is optimization of miniature, rectangular nozzles. A number of flat micronozzles were tested with ambient-temperature nitrogen and helium gas in a vacuum facility. The thrusters were etched out of silicon and had throat widths on the order of 350 microns and throat depths on the order of 250 microns. While these were half-sections of thrusters (two would be bonded together before firing), testing provided the performance trend for nozzles of this scale and geometry. Area ratios from 1 to 25 were tested, with thrust measured using an inverted pendulum thrust stand for nitrogen flows and a torsional thrust stand for helium. In the nitrogen testing, peak nozzle performance was achieved around area ratio of 5. In the helium series, nozzle performance peaked for the smallest nozzle tested area ratio 1.5. For both gases, there was a secondary performance peak above area ratio 15. At low chamber pressures (< 1.6 atm), nitrogen provided higher nozzle performance than helium. The performance curve for helium was steeper, however, and it appeared that helium would provide better performance than nitrogen at higher chamber pressures.

  20. Nozzle Thrust Optimization While Reducing Jet Noise

    NASA Technical Reports Server (NTRS)

    Seiner, J. M.; Gilinsky, M. M.

    1995-01-01

    A Bluebell nozzle design concept is proposed for jet noise reduction with minimal thrust loss or even thrust augmentation. A Bluebell nozzle has a sinusoidal lip line edge (chevrons) and a sinusoidal cross section shape with linear amplitude increasing downstream in the divergent nozzle part (corrugations). The experimental tests of several Bluebell nozzle designs have shown nose reduction relative to a convergent-divergent round nozzle with design exhaust number M(e) = 1.5. The best design provides an acoustic benefit near 4dB with about 1 percent thrust augmentation. For subsonic flow ((M(e)= 0.6)), the tests indicated that the present method for design of Bluebell nozzles gives less acoustic benefit and in most cases jet noise increased. The proposed designs incorporate analytical theory and 2D and 3D numerical simulations. Full Navier-Stokes and Euler solvers were utilized. Boundary layer effects were used. Several different designs were accounted for in the Euler applications.

  1. Site alteration effects from rocket exhaust impingment during a simulated Viking Mars landing. Part 1: Nozzle development and physical site alternation

    NASA Technical Reports Server (NTRS)

    Romine, G. L.; Reisert, T. D.; Gliozzi, J.

    1973-01-01

    A potential interference problem for the Viking '75 scientific investigation of the Martian surface resulting from retrorocket exhaust plume impingement of the surface was investigated experimentally and analytically. It was discovered that the conventional bell nozzle originally planned for the Viking Lander retrorockets would produce an unacceptably large amount of physical disturbance to the landing site. An experimental program was subsequently undertaken to find and/or develop a nozzle configuration which would significantly reduce the site alteration. A multiple nozzle configuration, consisting of 18 small bell nozzles, was shown to produce a level of disturbance that was considered by the Viking Lander Science Teams to be acceptable on the basis of results from full-scale tests on simulated Martian soils.

  2. Analysis of Flame Deflector Spray Nozzles in Rocket Engine Test Stands

    NASA Technical Reports Server (NTRS)

    Sachdev, Jai S.; Ahuja, Vineet; Hosangadi, Ashvin; Allgood, Daniel C.

    2010-01-01

    The development of a unified tightly coupled multi-phase computational framework is described for the analysis and design of cooling spray nozzle configurations on the flame deflector in rocket engine test stands. An Eulerian formulation is used to model the disperse phase and is coupled to the gas-phase equations through momentum and heat transfer as well as phase change. The phase change formulation is modeled according to a modified form of the Hertz-Knudsen equation. Various simple test cases are presented to verify the validity of the numerical framework. The ability of the methodology to accurately predict the temperature load on the flame deflector is demonstrated though application to an actual sub-scale test facility. The CFD simulation was able to reproduce the result of the test-firing, showing that the spray nozzle configuration provided insufficient amount of cooling.

  3. Method of creating a controlled interior surface configuration of passages within a substrate

    DOEpatents

    Dembowski, Peter V.; Schilke, Peter W.

    1983-01-01

    A method of creating a controlled interior surface configuration of passages within a substrate, particularly cooling passages of nozzles or buckets of a gas turbine, involves the hot isostatic pressing of a leachable passage insert whose surface carries the female image of the desired interior surface configuration inside the substrate followed by leaching of the insert from the substrate.

  4. Flow and acoustic features of a supersonic tapered nozzle

    NASA Astrophysics Data System (ADS)

    Gutmark, E.; Bowman, H. L.; Schadow, K. C.

    1992-05-01

    The acoustic and flow characteristics of a supersonic tapered jet were measured for free and shrouded flow configurations. Measurements were performed for a full range of pressure ratios including over- and underexpanded and design conditions. The supersonic tapered jet is issued from a converging-diverging nozzle with a 3∶1 rectangular slotted throat and a conical diverging section leading to a circular exit. The jet was compared to circular and rectangular supersonic jets operating at identical conditions. The distinct feature of the jet is the absence of screech tones in the entire range of operation. Its near-field pressure fluctuations have a wide band spectrum in the entire range of measurements, for Mach numbers of 1 to 2.5, for over- and underexpanded conditions. The free jet's spreading rate is nearly constant and similar to the rectangular jet, and in a shroud, the pressure drop it is inducing is linearly proportional to the primary jet Mach number. This behavior persisted in high adverse pressure gradients at overexpanded conditions, and with nozzle divergence angles of up to 35°, no inside flow separation was observed.

  5. Laser velocimeter measurements of the flow downstream of the Space Shuttle Main Engine high pressure oxidizer turbopump first-stage turbine nozzle

    NASA Technical Reports Server (NTRS)

    Ferguson, T. V.; Havskjold, G. L.; Rojas, L.

    1988-01-01

    A laser two-focus velocimeter was used in an open-loop water test facility in order to map the flowfield downstream of the SSME's high-pressure oxidizer turbopump first-stage turbine nozzle; attention was given to the effects of the upstream strut-downstream nozzle configuration on the flow at the rotor inlet, in order to estimate dynamic loads on the first-stage rotor blades. Velocity and flow angles were plotted as a function of circumferential position, and were found to clearly display the periodic behavior of the wake flow field. The influence of the upstream centerbody-supporting struts on the vane nozzle wake pattern was evident.

  6. Geomagnetic effects modelling for the PJM interconnection system. Part 2; Geomagnetically induced current study results

    SciTech Connect

    Prabhakara, F.S.; Hannett, L.N.; Ringlee, R.J. ); Ponder, J.Z. )

    1992-05-01

    The development of a computer program for calculation of geomagnetically induced current (GIC) and a GIC power system model for the Pennsylvania-New Jersey-Maryland Interconnection is described in this paper. Results of GIC for three different ionospheric source configurations are shown. A new method is presented for estimating GIC in unmetered parts of the system based on a few measurements and precalculated geomagnetic disturbance conditions. The use of an interactive, menu driven GIC program to study mitigation concepts including the effects of line outages, line series capacitors, transformer neutral blocking resistors and transformer neutral blocking capacitors is also presented.

  7. Improving Jet Reactor Configuration for Production of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Povitsky, Alex

    2000-01-01

    The jet mixing reactor has been proposed for the industrial production of fullerene carbon nanotubes. Here we study the flowfield of this reactor using the SIMPLER algorithm. Hot peripheral jets are used to enhance heating of the central jet by mixing with the ambiance of reactor. Numerous configurations of peripheral jets with various number of jets, distance between nozzles, angles between the central jet and a peripheral jets, and twisted configuration of nozzles are considered. Unlike the previous studies of jet mixing, the optimal configuration of peripheral jets produces strong non-uniformity of the central jet in a cross-section. The geometrical shape of reactor is designed to obtain a uniform temperature of a catalyst.

  8. YF 102 in-duct combustor noise measurements with a turbine nozzle, volume 1

    NASA Technical Reports Server (NTRS)

    Wilson, C. A.; Oconnell, J. M.

    1981-01-01

    The internal noise generated by an Avco Lycoming YF-102 engine combustor installed in a test rig was recorded. Two configurations were tested one with and one without the first stage turbine nozzle installed. Acoustic probes and accessories were used. Internal dynamic pressure level measurements were made at ten locations within the combustor. The combustor rig, the test procedures, and data acquisition and reduction systems are described. Tables and plots of narrow band and one third octave band pressure level spectra are included.

  9. Performance characteristics of an isolated coannular plug nozzle at transonic speeds

    NASA Technical Reports Server (NTRS)

    Mercer, C. E.; Burley, J. R., II

    1985-01-01

    The Langley 16-Foot Transonic Tunnel was used to evaluate the performance characteristics of a coannular plug nozzle at static conditions (Mach number of 0) and at Mach numbers from 0.65 to 1.20. Jet total pressure ratio was varied from 1.0 (jet off) to 10.0. Thirty-seven configurations generated by the combination of three geometric variables - plug angle, shroud boattail length (fixed exit radius), and shroud extension length - were tested.

  10. Performance of Single-Stage Turbine of Mark 25 Torpedo Power Plant with Two Special Nozzles. 1; Efficiency with 0.45-inch Rotor Blades

    NASA Technical Reports Server (NTRS)

    Schum, Harold J.; Whitney, Waren J.

    1949-01-01

    An investigation was made of the first-stage turbine of a Mark 25 torpedo power plant to determine the performance of the unity with two nozzle configurations and a special rotor having 0.45-inch blades instead of the standard length of 0.40 inch. Both nozzles had smaller passages than the nozzles of similar shape that were previously investigated. The performance of the nozzle-blade combinations is evaluated in terms of brake, rotor, and blade efficiency as functions of blade-jet speed ratio for three pressure ratios. Over the range of speeds and pressure ratios investigated, the efficiency with the nozzle having rectangular passages (J) was higher than that with a nozzle having circular passages (K). The difference in blade efficiencies varied from less than 0.010 at the lower blade-jet speed ratios for the three pressure ratios investigated to 0.030 at a pressure ratio of 8 and a blade-jet speed ratio of 0.295. The efficiencies with these tow nozzles were generally lower than those obtained with nozzles previously reported in combination with the 0.45-inch blades.

  11. Comparison of experimental surface pressures with theoretical predictions on twin two-dimensional convergent-divergent nozzles

    NASA Technical Reports Server (NTRS)

    Carlson, J. R.; Pendergraft, O. C., Jr.; Burley, J. R., II

    1986-01-01

    A three-dimensional subsonic aerodynamic panel code (VSAERO) was used to predict the effects of upper and lower external nozzle flap geometry on the external afterbody/nozzle pressure coefficient distributions and external nozzle drag of nonaxisymmetric convergent-divergent exhaust nozzles having parallel external sidewalls installed on a generic twin-engine high performance aircraft model. Nozzle static pressure coefficient distributions along the upper and lower surfaces near the model centerline and near the outer edges (corner) of the two surfaces were calculated, and nozzle drag was predicted using these surface pressure distributions. A comparison between the theoretical predictions and experimental wind tunnel data is made to evaluate the utility of the code in calculating the flow about these types of non-axisymmetric afterbody configurations. For free-stream Mach numbers of 0.60 and 0.90, the conditions where the flows were attached on the boattails yielded the best comparison between the theoretical predictions and the experimental data. For the Boattail terminal angles of greater than 15 deg., the experimental data for M = 0.60 and 0.90 indicated areas of separated flow, so the theoretical predictions failed to match the experimental data. Even though calculations of regions of separated flows are within the capabilities of the theoretical method, acceptable solutions were not obtained.

  12. Large-eddy simulation of cavitating nozzle and jet flows

    NASA Astrophysics Data System (ADS)

    Örley, F.; Trummler, T.; Hickel, S.; Mihatsch, M. S.; Schmidt, S. J.; Adams, N. A.

    2015-12-01

    We present implicit large-eddy simulations (LES) to study the primary breakup of cavitating liquid jets. The considered configuration, which consists of a rectangular nozzle geometry, adopts the setup of a reference experiment for validation. The setup is a generic reproduction of a scaled-up automotive fuel injector. Modelling of all components (i.e. gas, liquid, and vapor) is based on a barotropic two-fluid two-phase model and employs a homogenous mixture approach. The cavitating liquid model assumes thermodynamic- equilibrium. Compressibility of all phases is considered in order to capture pressure wave dynamics of collapse events. Since development of cavitation significantly affects jet break-up characteristics, we study three different operating points. We identify three main mechanisms which induce primary jet break-up: amplification of turbulent fluctuations, gas entrainment, and collapse events near the liquid-gas interface.

  13. Development of acoustically lined ejector technology for multitube jet noise suppressor nozzles by model and engine tests over a wide range of jet pressure ratios and temperatures

    NASA Technical Reports Server (NTRS)

    Atvars, J.; Paynter, G. C.; Walker, D. Q.; Wintermeyer, C. F.

    1974-01-01

    An experimental program comprising model nozzle and full-scale engine tests was undertaken to acquire parametric data for acoustically lined ejectors applied to primary jet noise suppression. Ejector lining design technology and acoustical scaling of lined ejector configurations were the major objectives. Ground static tests were run with a J-75 turbojet engine fitted with a 37-tube, area ratio 3.3 suppressor nozzle and two lengths of ejector shroud (L/D = 1 and 2). Seven ejector lining configurations were tested over the engine pressure ratio range of 1.40 to 2.40 with corresponding jet velocities between 305 and 610 M/sec. One-fourth scale model nozzles were tested over a pressure ratio range of 1.40 to 4.0 with jet total temperatures between ambient and 1088 K. Scaling of multielement nozzle ejector configurations was also studied using a single element of the nozzle array with identical ejector lengths and lining materials. Acoustic far field and near field data together with nozzle thrust performance and jet aerodynamic flow profiles are presented.

  14. Upper Stage Engine Composite Nozzle Extensions

    NASA Technical Reports Server (NTRS)

    Valentine, Peter G.; Allen, Lee R.; Gradl, Paul R.; Greene, Sandra E.; Sullivan, Brian J.; Weller, Leslie J.; Koenig, John R.; Cuneo, Jacques C.; Thompson, James; Brown, Aaron; Shigley, John K.; Dovey, Henry N.; Roberts, Robert K.

    2015-01-01

    Carbon-carbon (C-C) composite nozzle extensions are of interest for use on a variety of launch vehicle upper stage engines and in-space propulsion systems. The C-C nozzle extension technology and test capabilities being developed are intended to support National Aeronautics and Space Administration (NASA) and United States Air Force (USAF) requirements, as well as broader industry needs. Recent and on-going efforts at the Marshall Space Flight Center (MSFC) are aimed at both (a) further developing the technology and databases for nozzle extensions fabricated from specific CC materials, and (b) developing and demonstrating low-cost capabilities for testing composite nozzle extensions. At present, materials development work is concentrating on developing a database for lyocell-based C-C that can be used for upper stage engine nozzle extension design, modeling, and analysis efforts. Lyocell-based C-C behaves in a manner similar to rayon-based CC, but does not have the environmental issues associated with the use of rayon. Future work will also further investigate technology and database gaps and needs for more-established polyacrylonitrile- (PAN-) based C-C's. As a low-cost means of being able to rapidly test and screen nozzle extension materials and structures, MSFC has recently established and demonstrated a test rig at MSFC's Test Stand (TS) 115 for testing subscale nozzle extensions with 3.5-inch inside diameters at the attachment plane. Test durations of up to 120 seconds have been demonstrated using oxygen/hydrogen propellants. Other propellant combinations, including the use of hydrocarbon fuels, can be used if desired. Another test capability being developed will allow the testing of larger nozzle extensions (13.5- inch inside diameters at the attachment plane) in environments more similar to those of actual oxygen/hydrogen upper stage engines. Two C-C nozzle extensions (one lyocell-based, one PAN-based) have been fabricated for testing with the larger

  15. Static investigation of a two-dimensional convergent-divergent exhaust nozzle with multiaxis thrust-vectoring capability

    NASA Technical Reports Server (NTRS)

    Taylor, John G.

    1990-01-01

    An investigation was conducted in the Static Test Facility of the NASA Langley 16-Foot Transonic Tunnel to determine the internal performance of two-dimensional convergent-divergent nozzles designed to have simultaneous pitch and yaw thrust vectoring capability. This concept utilized divergent flap rotation of thrust vectoring in the pitch plane and deflection of flat yaw flaps hinged at the end of the sidewalls for yaw thrust vectoring. The hinge location of the yaw flaps was varied at four positions from the nozzle exit plane to the throat plane. The yaw flaps were designed to contain the flow laterally independent of power setting. In order to eliminate any physical interference between the yaw flap deflected into the exhaust stream and the divergent flaps, the downstream corners of both upper and lower divergent flaps were cut off to allow for up to 30 deg of yaw flap deflection. The impact of varying the nozzle pitch vector angle, throat area, yaw flap hinge location, yaw flap length, and yaw flap deflection angle on nozzle internal performance characteristics, was studied. High-pressure air was used to simulate jet exhaust at nozzle pressure ratios up to 7.0. Static results indicate that configurations with the yaw flap hinge located upstream of the exit plane provide relatively high levels of thrust vectoring efficiency without causing large losses in resultant thrust ratio. Therefore, these configurations represent a viable concept for providing simultaneous pitch and yaw thrust vectoring.

  16. Nozzle dam having a unitary plug

    DOEpatents

    Veronesi, Luciano; Wepfer, Robert M.

    1992-01-01

    Apparatus for sealing the primary-side coolant flow nozzles of a nuclear steam generator. The steam generator has relatively small diameter manway openings for providing access to the interior of the steam generator including the inside surface of each nozzle, the manway openings having a diameter substantially less than the inside diameter of each nozzle. The apparatus includes a bracket having an outside surface for matingly sealingly engaging the inside surface of the nozzle. The bracket also has a plurality of openings longitudinally therethrough and a plurality of slots transversely therein in communication with each opening. A plurality of unitary plugs sized to pass through the manway opening are matingly sealingly disposed in each opening of the bracket for sealingly plugging each opening. Each plug includes a plurality of arms operable to engage the slots of the bracket for connecting each plug to the bracket, so that the nozzle is sealed as the plugs seal the openings and are connected to the bracket.

  17. Nozzle dam having a unitary plug

    DOEpatents

    Veronesi, L.; Wepfer, R.M.

    1992-12-15

    Apparatus for sealing the primary-side coolant flow nozzles of a nuclear steam generator is disclosed. The steam generator has relatively small diameter manway openings for providing access to the interior of the steam generator including the inside surface of each nozzle, the manway openings having a diameter substantially less than the inside diameter of each nozzle. The apparatus includes a bracket having an outside surface for matingly sealingly engaging the inside surface of the nozzle. The bracket also has a plurality of openings longitudinally therethrough and a plurality of slots transversely therein in communication with each opening. A plurality of unitary plugs sized to pass through the manway opening are matingly sealingly disposed in each opening of the bracket for sealingly plugging each opening. Each plug includes a plurality of arms operable to engage the slots of the bracket for connecting each plug to the bracket, so that the nozzle is sealed as the plugs seal the openings and are connected to the bracket. 16 figs.

  18. Aeroelastic Modeling of a Nozzle Startup Transient

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Zhao, Xiang; Zhang, Sijun; Chen, Yen-Sen

    2014-01-01

    Lateral nozzle forces are known to cause severe structural damage to any new rocket engine in development during test. While three-dimensional, transient, turbulent, chemically reacting computational fluid dynamics methodology has been demonstrated to capture major side load physics with rigid nozzles, hot-fire tests often show nozzle structure deformation during major side load events, leading to structural damages if structural strengthening measures were not taken. The modeling picture is incomplete without the capability to address the two-way responses between the structure and fluid. The objective of this study is to develop a tightly coupled aeroelastic modeling algorithm by implementing the necessary structural dynamics component into an anchored computational fluid dynamics methodology. The computational fluid dynamics component is based on an unstructured-grid, pressure-based computational fluid dynamics formulation, while the computational structural dynamics component is developed under the framework of modal analysis. Transient aeroelastic nozzle startup analyses at sea level were performed, and the computed transient nozzle fluid-structure interaction physics presented,

  19. Integrity of the Plasma Magnetic Nozzle

    NASA Technical Reports Server (NTRS)

    Gerwin, Richard A.

    2009-01-01

    This report examines the physics governing certain aspects of plasma propellant flow through a magnetic nozzle, specifically the integrity of the interface between the plasma and the nozzle s magnetic field. The injection of 100s of eV plasma into a magnetic flux nozzle that converts thermal energy into directed thrust is fundamental to enabling 10 000s of seconds specific impulse and 10s of kW/kg specific power piloted interplanetary propulsion. An expression for the initial thickness of the interface is derived and found to be approx.10(exp -2) m. An algorithm is reviewed and applied to compare classical resistivity to gradient-driven microturbulent (anomalous) resistivity, in terms of the spatial rate and time integral of resistive interface broadening, which can then be related to the geometry of the nozzle. An algorithm characterizing plasma temperature, density, and velocity dependencies is derived and found to be comparable to classical resistivity at local plasma temperatures of approx. 200 eV. Macroscopic flute-mode instabilities in regions of "adverse magnetic curvature" are discussed; a growth rate formula is derived and found to be one to two e-foldings of the most unstable Rayleigh-Taylor (RT) mode. After establishing the necessity of incorporating the Hall effect into Ohm s law (allowing full Hall current to flow and concomitant plasma rotation), a critical nozzle length expression is derived in which the interface thickness is limited to about 1 ion gyroradius.

  20. RSRM nozzle fixed housing cooldown test

    NASA Technical Reports Server (NTRS)

    Bolieau, D. J.

    1989-01-01

    Flight 5 aft segments with nozzles were exposed to -17 F temperatures while awaiting shipment to KSC in February, 1989. No records were found which show that any previous nozzles were exposed to air temperatures as low as those seen by the Flight 5 nozzles. Thermal analysis shows that the temperature of the fixed housing, and forward and aft exit cone components dropped as low as -10 F. Structural analysis of the nozzles at these low temperatures show the forward and aft exit cone adhesive bonds to have a positive margin of safety, based on a 2.0 safety factor. These analyses show the normal and shear stresses in the fixed housing bond as low values. However, the hoop and meridinal stresses were predicted to be in the 4000 psi range; the failure stress allowable of EA913NA adhesive at -7 F. If the bonds did break in directions perpendicular to the surfaces, called bond crazing, no normal bond strength would be lost. Testing was conducted in two phases, showing that no degradation to the adhesive bonds occurred while the Flight 5 nozzles were subjected to subzero temperatures. The results of these tests are documented. Phase 1 testing cooled a full-scale RSRM insulated fixed housing to -13 F, with extensive bondline inspections. Phase 2 testing cooled the witness panel adhesive tensile buttions to -13 F, with failure strengths recorded before, during, and after the cooldown.

  1. Method of assembling a variable nozzle turbocharger

    SciTech Connect

    Burdette, F.; Fluery, J.; Roessler, M.

    1987-04-07

    This patent describes a turbocharger having an exhaust gas driven turbine rotatably mounted to a shaft having a compressor impeller thereon, a compressor housing enclosing the compressor impeller. It also has a center housing including bearing means for rotatably supporting the shaft, and a turbine housing enclosing the turbine and forming a volute therein. A method is described of assembling the turbocharger with a spring loaded nozzle ring comprising the steps of: mounting a flange member having a central opening to the center housing; pivotably mounting vanes to the nozzle ring; sliding a tube member having a tab at each end within the central opening; indexing one of the tabs within a slot in the flange member; sliding the nozzle ring onto the tube member; indexing the other tab within a slot in the nozzle ring; simultaneously mounting the turbine housing to the flange member and biasing the nozzle ring toward the turbine housing such that the vanes are spring loaded against a portion of the turbine housing.

  2. Design exploration for a single expansion ramp nozzle (SERN) using data mining

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Wang, Zhen-guo; Ingham, Derek B.; Ma, Lin; Pourkashanian, Mohamed

    2013-02-01

    The single expansion ramp nozzle is an essential component for hypersonic vehicles to improve their internal/external integral level and produce most of the thrust force. The two-dimensional coupled implicit Reynolds Averaged Navier-Stokes (RANS) equations and the two-equation RNG k-ɛ turbulent model have been employed to numerically simulate the flow field in a single expansion ramp nozzle, and the interactions between the parametric parameters and the objective functions, namely the thrust force and the lift force, have been investigated by using the data mining technique coupled with a design of the experiment. The obtained results show that the physical model has a good two-dimensional structure, and the numerical results show very good agreement with the available experimental data. At the same time, the grid scale has only a slight impact on the pressure distribution. The influences of the horizontal length of the inner nozzle, the external expansion ramp and the internal cowl expansion on the thrust force performance are substantial, as are the effects of the internal cowl expansion and the external expansion ramp on the lift force performance. Further, optimized configurations of the single expansion ramp nozzle are obtained by using single- and multi-objective design optimization methods coupled with the Kriging surrogate model, and the optimized performances show very good agreement with the numerical predictions. The discrepancies between the optimized performances and the numerical predictions are less than 0.05%, and the method proposed in this paper is efficient in designing and optimizing the nozzle configuration.

  3. Base Flow and Heat Transfer Characteristics of a Four-Nozzle Clustered Rocket Engine: Effect of Nozzle Pressure Ratio

    NASA Technical Reports Server (NTRS)

    Nallasamy, R.; Kandula, M.; Duncil, L.; Schallhorn, P.

    2010-01-01

    The base pressure and heating characteristics of a four-nozzle clustered rocket configuration is studied numerically with the aid of OVERFLOW Navier-Stokes code. A pressure ratio (chamber pressure to freestream static pressure) range of 990 to 5,920 and a freestream Mach number range of 2.5 to 3.5 are studied. The qualitative trends of decreasing base pressure with increasing pressure ratio and increasing base heat flux with increasing pressure ratio are correctly predicted. However, the predictions for base pressure and base heat flux show deviations from the wind tunnel data. The differences in absolute values between the computation and the data are attributed to factors such as perfect gas (thermally and calorically perfect) assumption, turbulence model inaccuracies in the simulation, and lack of grid adaptation.

  4. A Passive Cavity Concept for Improving the Off-Design Performance of Fixed-Geometry Exhaust Nozzles

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.; Gunther, Christopher L.; Hunter, Craig A.

    1996-01-01

    An investigation was conducted in the model preparation area of the Langley 16-Foot Transonic Tunnel to study a passive cavity concept for improving the off-design performance of fixed-geometry exhaust nozzles. Passive cavity ventilation (through a porous surface) was applied to divergent flap surfaces and tested at static conditions in a sub-scale, nonaxisymmetric, convergent-divergent nozzle. As part of a comprehensive investigation, force, moment and pressure measurements were taken and focusing schlieren flow visualization was obtained for a baseline configuration and D passive cavity configurations. All tests were conducted with no external flow and high-pressure air was used to simulate jet-exhaust flow at nozzle pressure ratios from 1.25 to approximately 9.50. Results indicate that baseline nozzle performance was dominated by unstable shock-induced boundary-layer separation at off-design conditions, which came about through the natural tendency of overexpanded exhaust flow to satisfy conservation requirements by detaching from the nozzle divergent flaps. Passive cavity ventilation added the ability to control off-design separation in the nozzle by either alleviating separation or encouraging stable separation of the exhaust flow. Separation alleviation offers potential for installed nozzle performance benefits by reducing drag at forward flight speeds, even though it may reduce off-design static thrust efficiency as much as 3.2 percent. Encouraging stable separation of the exhaust flow offers significant performance improvements at static, low NPR and low Mach number flight conditions by improving off-design static thrust efficiency as much as 2.8 percent. By designing a fixed-geometry nozzle with fully porous divergent flaps, where both cavity location and percent open porosity of the flaps could be varied, passive flow control would make it possible to improve off-design nozzle performance across a wide operating range. In addition, the ability to

  5. Design of high pressure waterjet nozzles

    NASA Technical Reports Server (NTRS)

    Mazzoleni, Andre P.

    1994-01-01

    The Hydroblast Research Cell at Marshall Space Flight Center is used to investigate the use of high pressure waterjets to strip paint, grease, adhesive and thermal spray coatings from various substrates. Current methods of cleaning often use ozone depleting chemicals (ODC) such as chlorinated solvents. High pressure waterjet cleaning has proven to be a viable alternative to the use of solvents. A popular method of waterjet cleaning involves the use of a rotating, multijet, high pressure water nozzle which is robotically controlled. This method enables rapid cleaning of a large area, but problems such as incomplete coverage and damage to the substrate from the waterjet have been observed. This report summarizes research consisting of identifying and investigating the basic properties of rotating, multijet, high pressure water nozzles, and how particular designs and modes of operation affect such things as stripping rate, standoff distance and completeness of coverage. The study involved computer simulations, an extensive literature review, and experimental studies of different nozzle designs.

  6. Design of high pressure waterjet nozzles

    NASA Astrophysics Data System (ADS)

    Mazzoleni, Andre P.

    1994-10-01

    The Hydroblast Research Cell at Marshall Space Flight Center is used to investigate the use of high pressure waterjets to strip paint, grease, adhesive and thermal spray coatings from various substrates. Current methods of cleaning often use ozone depleting chemicals (ODC) such as chlorinated solvents. High pressure waterjet cleaning has proven to be a viable alternative to the use of solvents. A popular method of waterjet cleaning involves the use of a rotating, multijet, high pressure water nozzle which is robotically controlled. This method enables rapid cleaning of a large area, but problems such as incomplete coverage and damage to the substrate from the waterjet have been observed. This report summarizes research consisting of identifying and investigating the basic properties of rotating, multijet, high pressure water nozzles, and how particular designs and modes of operation affect such things as stripping rate, standoff distance and completeness of coverage. The study involved computer simulations, an extensive literature review, and experimental studies of different nozzle designs.

  7. Flow-Field Surveys for Rectangular Nozzles

    NASA Technical Reports Server (NTRS)

    Zaman, K. B. M. Q.

    2012-01-01

    Flow field survey results for three rectangular nozzles are presented for a low subsonic condition obtained primarily by hot-wire anemometry. The three nozzles have aspect ratios of 2:1, 4:1 and 8:1. A fourth case included has 2:1 aspect ratio with chevrons added to the long edges. Data on mean velocity, turbulent normal and shear stresses as well as streamwise vorticity are presented covering a streamwise distance up to sixteen equivalent diameters from the nozzle exit. These detailed flow properties, including initial boundary layer characteristics, are usually difficult to measure in high speed flows and the primary objective of the study is to aid ongoing and future computational and noise modeling efforts.

  8. Performance comparison of a lobed-daisy mixer nozzle with a convergent nozzle at subsonic speeds

    NASA Technical Reports Server (NTRS)

    Maiden, D. L.

    1973-01-01

    An investigation to determine the performance, in terms of thrust minus nozzle axial force, of a lobed-daisy mixer nozzle has been conducted in a 16-foot transonic tunnel at static conditions and at Mach numbers from 0.40 to 0.90 at angles of attack from 4 minus to 8. Jet-total-pressure ratio was varied from about 1.2 to 2.0. The performance of a reference convergent nozzle with a similar nozzle throat area and length was used as a base line to evaluate the performance of the lobed-daisy mixer nozzle. The results of this investigation indicate that with no external airflow (Mach number M of 0), and at values of jet-total-pressure ratio between 1.2 and 2.0, the static thrust exerted by the lobed-daisy mixer nozzle is less than that of the convergent nozzle by about 10 percent of ideal gross thrust. About 3.4 percent of the thrust loss was attributed to an unintentional internal area expansion in the fan passage.

  9. Prototype Variable-Area Exhaust Nozzle Designed

    NASA Technical Reports Server (NTRS)

    Lee, Ho-Jun; Song, Gangbring

    2005-01-01

    Ongoing research in NASA Glenn Research Center s Structural Mechanics and Dynamics Branch to develop smart materials technologies for adaptive aeropropulsion components has resulted in the design of a prototype variable-area exhaust nozzle (see the preceding photograph). The novel design exploits the potential of smart materials to improve the performance of existing fixed-area exhaust nozzles by introducing new capabilities for adaptive shape control, vibration damping, and flow manipulation. The design utilizes two different smart materials: shape memory alloy wires as actuators and magnetorheological fluids as damper locks.

  10. Line drawing of anomaly discovered in redesigned shuttle motor nozzle

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Line drawing titled 'DM-9 Case-to-Nozzle Joint' shows anomaly discovered in redesigned shuttle motor nozzle. The second full-duration test firing of NASA's redesigned Space Shuttle solid rocket motor (SRM), designated DM-9, was conducted 12-23-87 at Morton Thiokol's Wasatch facility in Utah. A post-test examination of the motor has revealed an anomaly in one nozzle component. Material was discovered missing from the nozzle outer boot ring, a large carbon phenolic composite ring used to anchor one end of the flexible boot that allows the nozzle to move and 'steer' the vehicle. About one-third of the missing 160 degrees of missing ring material was found adjacent to the forward nozzle section inside the motor. This diagram shows the location of the nozzle joint on an assembled SRM, and points out the shaded location of the outer boot ring that circles the motor within the nozzle joint.

  11. Turbocharger with variable nozzle having vane sealing surfaces

    DOEpatents

    Arnold, Philippe; Petitjean, Dominique; Ruquart, Anthony; Dupont, Guillaume; Jeckel, Denis

    2011-11-15

    A variable nozzle for a turbocharger includes a plurality of vanes rotatably mounted on a nozzle ring and disposed in a nozzle flow path defined between the nozzle ring and an opposite nozzle wall. Either or both of the faces of the nozzle ring and nozzle wall include(s) at least one step that defines sealing surfaces positioned to be substantially abutted by airfoil surfaces of the vanes in the closed position of the vanes and to be spaced from the airfoil surfaces in positions other than the closed position. This substantial abutment between the airfoil surfaces and the sealing surfaces serves to substantially prevent exhaust gas from leaking past the ends of the airfoil portions. At the same time, clearances between the nozzle ring face and the end faces of the airfoil portions can be sufficiently large to prevent binding of the vanes under all operating conditions.

  12. Comparison of jet Mach number decay data with a correlation and jet spreading contours for a large variety of nozzles

    NASA Technical Reports Server (NTRS)

    Groesbeck, D. E.; Huff, R. G.; Vonglahn, U. H.

    1977-01-01

    Small-scale circular, noncircular, single- and multi-element nozzles with flow areas as large as 122 sq cm were tested with cold airflow at exit Mach numbers from 0.28 to 1.15. The effects of multi-element nozzle shape and element spacing on jet Mach number decay were studied in an effort to reduce the noise caused by jet impingement on externally blown flap (EBF) STOL aircraft. The jet Mach number decay data are well represented by empirical relations. Jet spreading and Mach number decay contours are presented for all configurations tested.

  13. Noise, Turbulence, and Thrust of Subsonic Free Jets from Lobed Nozzles

    NASA Technical Reports Server (NTRS)

    Zaman, K. B. M. Q.; Wang, F. Y.

    2002-01-01

    A study of noise benefit, vis-a-vis thrust penalty, and its correlation to turbulence intensities was conducted for free jets issuing from lobed nozzles. Four convergent nozzles with constant exit area were used in the experiments. Three of these were of rectangular lobed configuration having six, ten and fourteen lobes; the fourth was a circular nozzle. Increasing the number of lobes resulted in a progressive reduction in the turbulence intensities as well as in the overall radiated noise. The noise reduction was pronounced at the low frequency end of the spectrum. However, there was an increase in the high frequency noise that rendered the overall benefit less attractive when compared on a scaled-up A-weighted basis. A reduction in noise was accompanied by a commensurate reduction in the turbulent kinetic energy in the flow field. As expected, increasing the number of lobes involved progressive reduction in the thrust coefficient. Among the cases studied, the six-lobed nozzle had the optimum reduction in turbulence and noise with the least thrust penalty.

  14. Computational study of single-expansion-ramp nozzles with external burning

    NASA Technical Reports Server (NTRS)

    Yungster, Shaye; Trefny, Charles J.

    1992-01-01

    A computational investigation of the effects of external burning on the performance of single expansion ramp nozzles (SERN) operating at transonic speeds is presented. The study focuses on the effects of external heat addition and introduces a simplified injection and mixing model based on a control volume analysis. This simplified model permits parametric and scaling studies that would have been impossible to conduct with a detailed CFD analysis. The CFD model is validated by comparing the computed pressure distribution and thrust forces, for several nozzle configurations, with experimental data. Specific impulse calculations are also presented which indicate that external burning performance can be superior to other methods of thrust augmentation at transonic speeds. The effects of injection fuel pressure and nozzle pressure ratio on the performance of SERN nozzles with external burning are described. The results show trends similar to those reported in the experimental study, and provide additional information that complements the experimental data, improving our understanding of external burning flowfields. A study of the effect of scale is also presented. The results indicate that combustion kinetics do not make the flowfield sensitive to scale.

  15. Computational Noise Study of a Supersonic Short Conical Plug-Nozzle Jet

    NASA Technical Reports Server (NTRS)

    Das, Indu S.; Khavaran, Abbas; Das, A. P.

    1996-01-01

    A computational jet noise study of a short conical plug-nozzle (CPN) is presented. The CPN has an exit diameter of 45 mm and the geometrical configuration closely approximates that of an ideal contoured plug-nozzle having shockless flow at pressure ratio xi(sub d) = 3.62. The gasdynamics of the jet flows have been predicted using the CFD code, NPARC with k-epsilon turbulence model; these data are then used for noise computations based on the modified GE/MGB code. The study covers a range of pressure ratio, 2.0 less than or equal to xi less than or equal to 5.0. The agreement of the computational results with the available experimental data is favorable. The results indicate consistent noise reduction effectiveness of the CPN as compared to equivalent convergent, convergent-divergent and ideal contoured plug nozzles at all pressure ratios. At design pressure ratio, codes predict noise levels within 4.0 dB of the measurements; and at off-design pressure ratios, in general, within 5.0 dB except at very high frequencies when deviations up to 10 dB are noted. The shock formation mechanism in the CPN jet is noted to be basically different from those in the convergent and CD nozzle jets.

  16. Computational study of single-expansion-ramp nozzles with external burning

    NASA Astrophysics Data System (ADS)

    Yungster, Shaye; Trefny, Charles J.

    1992-04-01

    A computational investigation of the effects of external burning on the performance of single expansion ramp nozzles (SERN) operating at transonic speeds is presented. The study focuses on the effects of external heat addition and introduces a simplified injection and mixing model based on a control volume analysis. This simplified model permits parametric and scaling studies that would have been impossible to conduct with a detailed CFD analysis. The CFD model is validated by comparing the computed pressure distribution and thrust forces, for several nozzle configurations, with experimental data. Specific impulse calculations are also presented which indicate that external burning performance can be superior to other methods of thrust augmentation at transonic speeds. The effects of injection fuel pressure and nozzle pressure ratio on the performance of SERN nozzles with external burning are described. The results show trends similar to those reported in the experimental study, and provide additional information that complements the experimental data, improving our understanding of external burning flowfields. A study of the effect of scale is also presented. The results indicate that combustion kinetics do not make the flowfield sensitive to scale.

  17. Flaperon Modification Effect on Jet-Flap Interaction Noise Reduction for Chevron Nozzles

    NASA Technical Reports Server (NTRS)

    Thomas, Russell H.; Mengle, Vinod G.; Stoker, Robert W.; Brusniak, Leon; Elkoby, Ronen

    2007-01-01

    Jet-flap interaction (JFI) noise can become an important component of far field noise when a flap is immersed in the engine propulsive stream or is in its entrained region, as in approach conditions for under-the-wing engine configurations. We experimentally study the effect of modifying the flaperon, which is a high speed aileron between the inboard and outboard flaps, at both approach and take-off conditions using scaled models in a free jet. The flaperon modifications were of two types: sawtooth trailing edge and mini vortex generators (vg s). Parametric variations of these two concepts were tested with a round coaxial nozzle and an advanced chevron nozzle, with azimuthally varying fan chevrons, using both far field microphone arrays and phased microphone arrays for source diagnostics purposes. In general, the phased array results corroborated the far field results in the upstream quadrant pointing to JFI near the flaperon trailing edge as the origin of the far field noise changes. Specific sawtooth trailing edges in conjunction with the round nozzle gave marginal reduction in JFI noise at approach, and parallel co-rotating mini-vg s were somewhat more beneficial over a wider range of angles, but both concepts were noisier at take-off conditions. These two concepts had generally an adverse JFI effect when used in conjunction with the advanced chevron nozzle at both approach and take-off conditions.

  18. Scramjet exhaust simulation technique for hypersonic aircraft nozzle design and aerodynamic tests

    NASA Technical Reports Server (NTRS)

    Hunt, J. L.; Talcott, N. A., Jr.; Cubbage, J. M.

    1977-01-01

    Current design philosophy for scramjet-powered hypersonic aircraft results in configurations with the entire lower fuselage surface utilized as part of the propulsion system. The lower aft-end of the vehicle acts as a high expansion ratio nozzle. Not only must the external nozzle be designed to extract the maximum possible thrust force from the high energy flow at the combustor exit, but the forces produced by the nozzle must be aligned such that they do not unduly affect aerodynamic balance. The strong coupling between the propulsion system and aerodynamics of the aircraft makes imperative at least a partial simulation of the inlet, exhaust, and external flows of the hydrogen-burning scramjet in conventional facilities for both nozzle formulation and aerodynamic-force data acquisition. Aerodynamic testing methods offer no contemporary approach for such vehicle design requirements. NASA-Langley has pursued an extensive scramjet/airframe integration R&D program for several years and has recently developed a promising technique for simulation of the scramjet exhaust flow for hypersonic aircraft. Current results of the research program to develop a scramjet flow simulation technique through the use of substitute gas blends are described in this paper.

  19. Noise of Embedded High Aspect Ratio Nozzles

    NASA Technical Reports Server (NTRS)

    Bridges, James E.

    2011-01-01

    A family of high aspect ratio nozzles were designed to provide a parametric database of canonical embedded propulsion concepts. Nozzle throat geometries with aspect ratios of 2:1, 4:1, and 8:1 were chosen, all with convergent nozzle areas. The transition from the typical round duct to the rectangular nozzle was designed very carefully to produce a flow at the nozzle exit that was uniform and free from swirl. Once the basic rectangular nozzles were designed, external features common to embedded propulsion systems were added: extended lower lip (a.k.a. bevel, aft deck), differing sidewalls, and chevrons. For the latter detailed Reynolds-averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) simulations were made to predict the thrust performance and to optimize parameters such as bevel length, and chevron penetration and azimuthal curvature. Seventeen of these nozzles were fabricated at a scale providing a 2.13 inch diameter equivalent area throat." ! The seventeen nozzles were tested for far-field noise and a few data were presented here on the effect of aspect ratio, bevel length, and chevron count and penetration. The sound field of the 2:1 aspect ratio rectangular jet was very nearly axisymmetric, but the 4:1 and 8:1 were not, the noise on their minor axes being louder than the major axes. Adding bevel length increased the noise of these nozzles, especially on their minor axes, both toward the long and short sides of the beveled nozzle. Chevrons were only added to the 2:1 rectangular jet. Adding 4 chevrons per wide side produced some decrease at aft angles, but increased the high frequency noise at right angles to the jet flow. This trend increased with increasing chevron penetration. Doubling the number of chevrons while maintaining their penetration decreased these effects. Empirical models of the parametric effect of these nozzles were constructed and quantify the trends stated above." Because it is the objective of the Supersonics Project that

  20. Characterization of hydraulic nozzles for droplet size and spray coverage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spray coverage specifications for commercially available nozzles could help applicators determine the optimal nozzles for effective control of insects, diseases and weeds. Spray coverage and deposit density from seven types of nozzles at three different flow rates (0.76, 1.14 and 2.27 l min-1) and t...

  1. Jet Nozzle Having Centerbody for Enhanced Exit Area Mixing

    NASA Technical Reports Server (NTRS)

    Seiner, John M. (Inventor); Gilinsky, Mikhail M. (Inventor)

    1999-01-01

    A nozzle arrangement includes a nozzle and a centerbody. The longitudinal axis of the centerbody is coaxially aligned with the nozzle. The centerbody has a free end portion shaped to create vortices in exhaust exiting the exit area. The vortices enhance mixing action in the exhaust and reduce exhaust noise while augmenting thrust.

  2. 46 CFR 118.320 - Fire hoses and nozzles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Fire hoses and nozzles. 118.320 Section 118.320 Shipping... System § 118.320 Fire hoses and nozzles. (a) A fire hose with a nozzle must be attached to each fire... provided, hoses may be temporarily removed during heavy weather or cargo handling operations,...

  3. 46 CFR 118.320 - Fire hoses and nozzles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Fire hoses and nozzles. 118.320 Section 118.320 Shipping... System § 118.320 Fire hoses and nozzles. (a) A fire hose with a nozzle must be attached to each fire... provided, hoses may be temporarily removed during heavy weather or cargo handling operations,...

  4. 46 CFR 118.320 - Fire hoses and nozzles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Fire hoses and nozzles. 118.320 Section 118.320 Shipping... System § 118.320 Fire hoses and nozzles. (a) A fire hose with a nozzle must be attached to each fire... provided, hoses may be temporarily removed during heavy weather or cargo handling operations,...

  5. 46 CFR 118.320 - Fire hoses and nozzles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Fire hoses and nozzles. 118.320 Section 118.320 Shipping... System § 118.320 Fire hoses and nozzles. (a) A fire hose with a nozzle must be attached to each fire... provided, hoses may be temporarily removed during heavy weather or cargo handling operations,...

  6. 46 CFR 118.320 - Fire hoses and nozzles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Fire hoses and nozzles. 118.320 Section 118.320 Shipping... System § 118.320 Fire hoses and nozzles. (a) A fire hose with a nozzle must be attached to each fire... provided, hoses may be temporarily removed during heavy weather or cargo handling operations,...

  7. Methodology for Three Dimensional Nozzle Design

    NASA Technical Reports Server (NTRS)

    Ferri, A.; Dash, S.; Delguidice, P.

    1974-01-01

    Criteria for the selection and methods of analysis for designing a hypersonic scramjet nozzle are discussed. The criteria are based on external and internal flow requirements, related to drag, lift, and pitching moments of the vehicle and thrust of the engine. The steps involved in establishing the criteria are analyzed. Mathematical models of the design procedure are provided.

  8. Low thermal stress ceramic turbine nozzle

    DOEpatents

    Glezer, B.; Bagheri, H.; Fierstein, A.R.

    1996-02-27

    A turbine nozzle vane assembly having a preestablished rate of thermal expansion is positioned in a gas turbine engine and is attached to conventional metallic components, the metallic components having a preestablished rate of thermal expansion greater than the preestablished rate of thermal expansion of the turbine nozzle vane assembly. The turbine nozzle vane assembly includes an outer shroud and an inner shroud having a plurality of vanes there between. Each of the plurality of vanes have a device for heating and cooling a portion of each of the plurality of vanes. Furthermore, the inner shroud has a plurality of bosses attached thereto. A cylindrical member has a plurality of grooves formed therein and each of the plurality of bosses are positioned in corresponding ones of the plurality of grooves. The turbine nozzle vane assembly provides an economical, reliable and effective ceramic component having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the other component. 4 figs.

  9. Clamp and Gas Nozzle for TIG Welding

    NASA Technical Reports Server (NTRS)

    Gue, G. B.; Goller, H. L.

    1982-01-01

    Tool that combines clamp with gas nozzle is aid to tungsten/inert-gas (TIG) welding in hard-to-reach spots. Tool holds work to be welded while directing a stream of argon gas at weld joint, providing an oxygen-free environment for tungsten-arc welding.

  10. Hydrogen/Air Fuel Nozzle Emissions Experiments

    NASA Technical Reports Server (NTRS)

    Smith, Timothy D.

    2001-01-01

    The use of hydrogen combustion for aircraft gas turbine engines provides significant opportunities to reduce harmful exhaust emissions. Hydrogen has many advantages (no CO2 production, high reaction rates, high heating value, and future availability), along with some disadvantages (high current cost of production and storage, high volume per BTU, and an unknown safety profile when in wide use). One of the primary reasons for switching to hydrogen is the elimination of CO2 emissions. Also, with hydrogen, design challenges such as fuel coking in the fuel nozzle and particulate emissions are no longer an issue. However, because it takes place at high temperatures, hydrogen-air combustion can still produce significant levels of NOx emissions. Much of the current research into conventional hydrocarbon-fueled aircraft gas turbine combustors is focused on NOx reduction methods. The Zero CO2 Emission Technology (ZCET) hydrogen combustion project will focus on meeting the Office of Aerospace Technology goal 2 within pillar one for Global Civil Aviation reducing the emissions of future aircraft by a factor of 3 within 10 years and by a factor of 5 within 25 years. Recent advances in hydrocarbon-based gas turbine combustion components have expanded the horizons for fuel nozzle development. Both new fluid designs and manufacturing technologies have led to the development of fuel nozzles that significantly reduce aircraft emissions. The goal of the ZCET program is to mesh the current technology of Lean Direct Injection and rocket injectors to provide quick mixing, low emissions, and high-performance fuel nozzle designs. An experimental program is planned to investigate the fuel nozzle concepts in a flametube test rig. Currently, a hydrogen system is being installed in cell 23 at NASA Glenn Research Center's Research Combustion Laboratory. Testing will be conducted on a variety of fuel nozzle concepts up to combustion pressures of 350 psia and inlet air temperatures of 1200 F

  11. Computational Studies of Magnetic Nozzle Performance

    NASA Technical Reports Server (NTRS)

    Ebersohn, Frans H.; Longmier, Benjamin W.; Sheehan, John P.; Shebalin, John B.; Raja, Laxminarayan

    2013-01-01

    An extensive literature review of magnetic nozzle research has been performed, examining previous work, as well as a review of fundamental principles. This has allow us to catalog all basic physical mechanisms which we believe underlie the thrust generation process. Energy conversion mechanisms include the approximate conservation of the magnetic moment adiabatic invariant, generalized hall and thermoelectric acceleration, swirl acceleration, thermal energy transformation into directed kinetic energy, and Joule heating. Momentum transfer results from the interaction of the applied magnetic field with currents induced in the plasma plume., while plasma detachment mechanisms include resistive diffusion, recombination and charge exchange collisions, magnetic reconnection, loss of adiabaticity, inertial forces, current closure, and self-field detachment. We have performed a preliminary study of Hall effects on magnetic nozzle jets with weak guiding magnetic fields and weak expansions (p(sub jet) approx. = P(sub background)). The conclusion from this study is that the Hall effect creates an azimuthal rotation of the plasma jet and, more generally, creates helical structures in the induced current, velocity field, and magnetic fields. We have studied plasma jet expansion to near vacuum without a guiding magnetic field, and are presently including a guiding magnetic field using a resistive MHD solver. This research is progressing toward the implementation of a full generalized Ohm's law solver. In our paper, we will summarize the basic principle, as well as the literature survey and briefly review our previous results. Our most recent results at the time of submittal will also be included. Efforts are currently underway to construct an experiment at the University of Michigan Plasmadynamics and Electric Propulsion Laboratory (PEPL) to study magnetic nozzle physics for a RF-thruster. Our computational study will work directly with this experiment to validate the numerical

  12. Air-assist fuel injection nozzle

    SciTech Connect

    Klomp, E.D.

    1987-09-15

    An air-assist fuel injection nozzle is described for use in discharging fuel into an associate combustion chamber of an internal combustion engine. The injection nozzle includes a nozzle body means. The straight walled spray tip portion has a plurality of radial discharge orifices extending. An axial bore in the body means extends from the opposite end to define a bushing, a needle plunger reciprocably received in the bushing between a fully raised position and a fully depressed position corresponding to the end of a suction stroke and the end of a pump stroke, respectively. The needle plunger has a radial supply passage and a radial discharge ports angularly aligned with the radial discharge orifices, wherein the discharge ports are in flow communication with the blind bore. The needle plunger and the interior portion of the enclosed end of the nozzle body means define a variable volume pump chamber. The nozzle body means includes a supply passage means with a check valve in fluid communication with the radial supply passage when the needle plunger is in the raised position. The opposite end of the supply passage means is to sequentially receive a metered quantity of pressurized fuel, and the needle plunger allows aeriform fluid flow from the combustion chamber into the pump chamber. The needle plunger blocks flow through the radial discharge orifices until such time as the needle plunger has moved a predetermined axial extent so that the radial discharge ports come into alignment with the radial discharge orifices to initiate an air-assist discharge of air, fuel vapors and fuel from the radial discharge orifices.

  13. Wind Tunnel Model Design for Sonic Boom Studies of Nozzle Jet with Shock Interactions

    NASA Technical Reports Server (NTRS)

    Cliff, Susan E.; Denison, Marie; Sozer, Emre; Moini-Yekta, Shayan

    2016-01-01

    NASA and Industry are performing vehicle studies of configurations with low sonic boom pressure signatures. The computational analyses of modern configuration designs have matured to the point where there is confidence in the prediction of the pressure signature from the front of the vehicle, but uncertainty in the aft signatures with often greater boundary layer effects and nozzle jet pressures. Wind tunnel testing at significantly lower Reynolds numbers than in flight and without inlet and nozzle jet pressures make it difficult to accurately assess the computational solutions of flight vehicles. A wind tunnel test in the NASA Ames 9- by 7-Foot Supersonic Wind Tunnel from Mach 1.6 to 2.0 will be used to assess the effects of shocks from components passing through nozzle jet plumes on the sonic boom pressure signature and provide datasets for comparison with CFD codes. A large number of high-fidelity numerical simulations of wind tunnel test models with a variety of shock generators that simulate horizontal tails and aft decks have been studied to provide suitable models for sonic boom pressure measurements using a minimally intrusive pressure rail in the wind tunnel. The computational results are presented and the evolution of candidate wind tunnel models is summarized and discussed in this paper.

  14. Jet noise results from static, wind tunnel, and flight tests of conical and mechanical suppressor nozzles

    NASA Astrophysics Data System (ADS)

    McKinnon, R. A.; Johnson, E. S.; Atencio, A., Jr.

    1981-10-01

    Results of jet noise suppression tests conducted on a Rolls-Royce Viper 601 turbojet engine are reported. Seven exhaust nozzle configurations are tested, including two conical nozzles, two suppressor mixers, and three treated ejector configurations with different ejector inlets. Tests are conducted at the NASA Ames outdoor static test facility and the 40- by 80-ft wind tunnel facility at minimum tunnel flow velocity and normal flow velocities of 230 and 290 ft/sec. Near-field multiple sideline noise levels are projected to the far fields to compare far-field fixed microphone outdoor static noise levels, and wind tunnel near-field noise data are projected to the far field and flight distances to compare with noise levels recorded from an Hs-125 aircraft. Near-field outdoor noise data duplicate the far-field data recorded from fixed microphones within 2 PNdB, and the Douglas mechanical jet noise suppressor/treated ejector exhaust system achieves a noise reduction of 12 EPNdB relative to a conic reference nozzle at equal thrust in flight.

  15. Jet noise results from static, wind tunnel, and flight tests of conical and mechanical suppressor nozzles

    NASA Technical Reports Server (NTRS)

    Mckinnon, R. A.; Johnson, E. S.; Atencio, A., Jr.

    1981-01-01

    Results of jet noise suppression tests conducted on a Rolls-Royce Viper 601 turbojet engine are reported. Seven exhaust nozzle configurations are tested, including two conical nozzles, two suppressor mixers, and three treated ejector configurations with different ejector inlets. Tests are conducted at the NASA Ames outdoor static test facility and the 40- by 80-ft wind tunnel facility at minimum tunnel flow velocity and normal flow velocities of 230 and 290 ft/sec. Near-field multiple sideline noise levels are projected to the far fields to compare far-field fixed microphone outdoor static noise levels, and wind tunnel near-field noise data are projected to the far field and flight distances to compare with noise levels recorded from an Hs-125 aircraft. Near-field outdoor noise data duplicate the far-field data recorded from fixed microphones within 2 PNdB, and the Douglas mechanical jet noise suppressor/treated ejector exhaust system achieves a noise reduction of 12 EPNdB relative to a conic reference nozzle at equal thrust in flight.

  16. Hydrogen no-vent fill testing in a 5 cubic foot (142 liter) tank using spray nozzle and spray bar liquid injection

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.; Nyland, Ted W.

    1992-01-01

    A total of 38 hydrogen no-vent fill tests were performed in this test series using various size spray nozzles and a spray bar with different hole sizes in a 5 cubic foot receiver tank. Fill levels of 90 percent by volume or greater were achieved in 26 of the tests while maintaining a receiver tank pressure below 30 psia. Spray nozzles were mounted at the top of the tank, whereas, the spray bar was centered in the tank axially. The spray nozzle no-vent fills demonstrated tank pressure and temperature responses comparable to previous test series. Receiver tank pressure responses for the spray bar configuration were similar to the spray nozzle tests with the pressure initially rising rapidly, then leveling off as vapor condenses onto the discharging liquid streams, and finally ramping up near the end of the test due to ullage compression. Both liquid injection techniques tested were capable of filling the receiver tank to 90 percent under variable test conditions. Comparisons between the spray nozzle and spray bar configurations for well matched test conditions indicate the spray nozzle injection technique is more effective in minimizing the receiving tank pressure throughout a no-vent fill compared to the spray bar under normal gravity conditions.

  17. Full Navier-Stokes analysis of a two-dimensional mixer/ejector nozzle for noise suppression

    NASA Technical Reports Server (NTRS)

    Debonis, James R.

    1992-01-01

    A three-dimensional full Navier-Stokes (FNS) analysis was performed on a mixer/ejector nozzle designed to reduce the jet noise created at takeoff by a future supersonic transport. The PARC3D computational fluid dynamics (CFD) code was used to study the flow field of the nozzle. The grid that was used in the analysis consisted of approximately 900,000 node points contained in eight grid blocks. Two nozzle configurations were studied: a constant area mixing section and a diverging mixing section. Data are presented for predictions of pressure, velocity, and total temperature distributions and for evaluations of internal performance and mixing effectiveness. The analysis provided good insight into the behavior of the flow.

  18. Hot wire anemometer measurements in the unheated air flow tests of the SRB nozzle-to-case joint

    NASA Technical Reports Server (NTRS)

    Ramachandran, N.

    1988-01-01

    Hot-Wire Anemometer measurements made in the Solid Rocket Booster (SRB) nozzle-to-case joint are discussed. The study was undertaken to glean additional information on the circumferential flow induced in the SRB nozzle joint and the effect of this flow on the insulation bonding flaws. The tests were conducted on a full-scale, 2-D representation of a 65-in long segment of the SRB nozzle joint, with unheated air as the working fluid. Both the flight Mach number and Reynolds number were matched simultaneously and different pressure gradients imposed along the joint face were investigated. Hot-wire anemometers were used to obtain velocity data for different joint gaps and debond configurations. The procedure adopted for hot-wire calibration and use is outlined and the results from the tests summarized.

  19. Effect of tail size reductions on longitudinal aerodynamic characteristics of a three surface F-15 model with nonaxisymmetric nozzles

    NASA Technical Reports Server (NTRS)

    Frassinelli, Mark C.; Carson, George T., Jr.

    1990-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of horizontal and vertical tail size reductions on the longitudinal aerodynamic characteristics of a modified F-15 model with canards and 2-D convergent-divergent nozzles. Quantifying the drag decrease at low angles of attack produced by tail size reductions was the primary focus. The model was tested at Mach numbers of 0.40, 0.90, and 1.20 over an angle of attack of -2 degree to 10 degree. The nozzle exhaust flow was simulated using high pressure air at nozzle pressure ratios varying from 1.0 (jet off) to 7.5. Data were obtained on the baseline configuration with and without tails as well as with reduced horizontal and/or vertical tail sizes that were 75, 50, and 25 percent of the baseline tail areas.

  20. Space Shuttle Main Engine nozzle thermal protection system

    NASA Technical Reports Server (NTRS)

    Nordlund, R. M.

    1985-01-01

    Two of the three Space Shuttle Main Engine (SSME) nozzles are exposed to significant reentry aeroheating loads. To ensure reusability of the Nozzle Assembly, the nozzle primary structure must not exceed specific temperature limits. Due to the thermal, pressure, and dynamic flexing of the nozzle during a mission cycle, an appropriate insulating system must have significant flexibility. Recent missions have demonstrated nozzle reentry aeroheating rates and heat loads much higher than predictions, higher than the capability of the original insulating system. A new insulating system has been developed using similar materials in an aerodynamically 'smooth' shape to both reduce the incoming heating and increase radiation cooling.

  1. Pitot pressure measurements in flow fields behind circular-arc nozzles with exhaust jets at subsonic free-stream Mach numbers. [langley 16 foot transonic tunnel

    NASA Technical Reports Server (NTRS)

    Mason, M. L.; Putnam, L. E.

    1979-01-01

    The flow field behind a circular arc nozzle with exhaust jet was studied at subsonic free stream Mach numbers. A conical probe was used to measure the pitot pressure in the jet and free stream regions. Pressure data were recorded for two nozzle configurations at nozzle pressure ratios of 2.0, 2.9, and 5.0. At each set of test conditions, the probe was traversed from the jet center line into the free stream region at seven data acquisition stations. The survey began at the nozzle exit and extended downstream at intervals. The pitot pressure data may be applied to the evaluation of computational flow field models, as illustrated by a comparison of the flow field data with results of inviscid jet plume theory.

  2. A 1/10 Scale Model Test of a Fixed Chute Mixer-Ejector Nozzle in Unsuppressed Model. Part 1; Test Overview

    NASA Technical Reports Server (NTRS)

    Wolter, John D.

    2007-01-01

    This paper discusses a test of a nozzle concept for a high-speed commercial aircraft. While a great deal of effort has been expended to und erstand the noise-suppressed, take-off performance of mixer-ejector n ozzles, little has been done to assess their performance in unsuppressed mode at other flight conditions. To address this, a 1/10th scale m odel mixer-ejector nozzle in unsuppressed mode was tested at conditio ns representing transonic acceleration, supersonic cruise, subsonic cruise, and approach. Various configurations were tested to understand the effects of acoustic liners and several geometric parameters, such as throat area, expansion ratio, and nozzle length on nozzle performance. Thrust, flow, and internal pressures were measured. A statistica l model of the peak thrust coefficient results is presented and discussed.

  3. Euler solutions for an unbladed jet engine configuration

    NASA Technical Reports Server (NTRS)

    Stewart, Mark E. M.

    1992-01-01

    An Euler solution for an axisymmetric jet engine configuration without blade effects is presented. The Euler equations are solved on a multiblock grid which covers a domain including the inlet, bybass duct, core passage, nozzle, and the far field surrounding the engine. The simulation is verified by considering five theoretical properties of the solution. The solution demonstrates both multiblock grid generation techniques and a foundation for a full jet engine throughflow calculation.

  4. Euler solutions for an unbladed jet engine configuration

    NASA Technical Reports Server (NTRS)

    Stewart, Mark E. M.

    1991-01-01

    A Euler solution for an axisymmetric jet engine configuration without blade effects is presented. The Euler equations are solved on a multiblock grid which covers a domain including the inlet, bypass duct, core passage, nozzle, and the far field surrounding the engine. The simulation is verified by considering five theoretical properties of the solution. The solution demonstrates both multiblock grid generation techniques and a foundation for a full jet engine throughflow calculation.

  5. Alternatives to Silicon Rubber Thermal Barrier in RSRM Nozzle Joints

    NASA Technical Reports Server (NTRS)

    Totman, Peter D.; Prince, Andrew; Frost, Doug; Himebaugh, Paul

    1999-01-01

    Thiokol Propulsion encountered a situation where gas path can form in the Filler material in joints between the phenolic in the Space Shuttle Reusable Solid Rocket Motor nozzle. An investigation determined that the method for injecting the filler material into the joint created a pressurized pocket of air that forced its way to the surface while the filler was curing. The path that the air took remained open some situations leaving a path for hot gas to get deep into the joint. The condition that created the gas path has been corrected by modifications to the manufacturing process, but a design solution that would reduce processing time is being pursued. A strip of open cell installed deep into the joint, can serve as a barrier to the Filler material. Testing indicates that the foam eliminates the pressure pocket, and does not prevent detection of leakage of the o-ring seals during leak test. Open cell foam does not have thermal resistance capability and mechanical structure, which would be required in the event of a gas path. A replacement to open cell foam is now being considered. Braided carbon fiber rope has the permeability characteristics of foam and it has thermal resistance characteristics as well. Braided carbon fiber rope (BCFR) has been tested in simulated joints in subscale rocket motor. Results of the testing indicate that braided carbon fiber rope can significantly reduce gas temperature by as much es 3000 F in a nozzle joint configuration. BCFR can be installed as a barrier to stop the joint filler material or it can used as the thermal barrier alone.

  6. High-frequency jet nozzle actuators for noise reduction

    NASA Astrophysics Data System (ADS)

    Davis, Christopher L.; Calkins, Frederick T.; Butler, George W.

    2003-08-01

    Rules governing airport noise levels are becoming more restrictive and will soon affect the operation of commercial air traffic. Sound produced by jet engine exhaust, particularly during takeoff, is a major contributor to the community noise problem. The noise spectrum is broadband in character and is produced by turbulent mixing of primary, secondary, and ambient streams of the jet engine exhaust. As a potential approach to controlling the noise levels, piezoelectric bimorph actuators have been tailored to enhance the mixing of a single jet with its quiescent environment. The actuators are located at the edge of the nozzle and protrude into the exhaust stream. Several actuator configurations were considered to target two excitation frequencies, 250 Hz and 900 Hz, closely coupled to the naturally unstable frequencies of the mixing process. The piezoelectric actuators were constructed of 10 mil thick d31 poled wafer PZT-5A material bonded to either 10 or 20 mil thick spring steel substrates. Linear analytical beam models and NASTRAN finite element models were used to predict and assess the dynamic performance of the actuators. Experimental mechanical and electrical performance measurements were used to validate the models. A 3 inch diameter nozzle was fitted with actuators and tested in the Boeing Quiet Air Facility with the jet velocity varied from 50 to 1000 ft/s. Performance was evaluated using near-field and far-field acoustic data, flow visualization, and actuator health data. The overall sound pressure level produced from the 3 inch diameter jet illustrates the effect of both static and active actuators.

  7. Cold Flow Determination of the Internal Flow Environment Around the Submerged TVC Nozzle for the Space Shuttle SRM

    NASA Technical Reports Server (NTRS)

    Whitesides, R. H.; Ghosh, A.; Jenkins, S. L.; Bacchus, D. L.

    1989-01-01

    A series of subscale cold flow tests was performed to quantify the gas flow characteristics at the aft end of the Space Shuttle Solid Rocket Motor. This information was used to support the analyses of the redesigned nozzle/case joint. A portion of the thermal loads at the joint are due to the circumferential velocities and pressure gradients caused primarily by the gimbaling of the submerged nose TVC nozzle. When the nozzle centerline is vectored with respect to the motor centerline, asymmetries are set up in the flow field under the submerged nozzle and immediately adjacent to the nozzle/case joint. Specific program objectives included: determination of the effects of nozzle gimbal angle and propellant geometry on the circumferential flow field; measurement of the static pressure and gas velocities in the vicinity of the nozzle/case joint; use of scaling laws to apply the subscale cold flow data to the full scale SRM; and generation of data for use in validation of 3-D computational fluid dynamic, CFD, models of the SRM flow field. These tests were conducted in the NASA Marshall Space Flight Center Airflow Facility with a 7.5 percent scale model of the aft segment of the SRM. Static and dynamic pressures were measured in the model to quantify the flow field. Oil flow data was also acquired to obtain qualitative visual descriptions of the flow field. Nozzle gimbal angles of 0, 3.5, and 7 deg were used with propellant grain configurations corresponding to motor burn times of 0, 9, 19, and 114 seconds. This experimental program was successful in generating velocity and pressure gradient data for the flow field around the submerged nose nozzle of the Space Shuttle SRM at various burn times and gimbal angles. The nature of the flow field adjacent to the nozzle/case joint was determined with oil droplet streaks, and the velocity and pressure gradients were quantified with pitot probes and wall static pressure measurements. The data was applied to the full scale SRM thru

  8. Turbulence Measurements of Separate Flow Nozzles with Mixing Enhancement Features

    NASA Technical Reports Server (NTRS)

    Bridges, James; Wernet, Mark P.

    2002-01-01

    Comparison of turbulence data taken in three separate flow nozzles, two with mixing enhancement features on their core nozzle, shows how the mixing enhancement features modify turbulence to reduce jet noise. The three nozzles measured were the baseline axisymmetric nozzle 3BB, the alternating chevron nozzle, 3A12B, with 6-fold symmetry, and the flipper tab nozzle 3T24B also with 6-fold symmetry. The data presented show the differences in turbulence characteristics produced by the geometric differences in the nozzles, with emphasis on those characteristics of interest in jet noise. Among the significant findings: the enhanced mixing devices reduce turbulence in the jet mixing region while increasing it in the fan/core shear layer, the ratios of turbulence components are significantly altered by the mixing devices, and the integral lengthscales do not conform to any turbulence model yet proposed. These findings should provide guidance for modeling the statistical properties of turbulence to improve jet noise prediction.

  9. Nuclear thermal rocket nozzle testing and evaluation program

    SciTech Connect

    Davidian, K.O.; Kacynski, K.J. )

    1993-01-20

    Performance characteristics of the Nuclear Thermal Rocket can be enhanced through the use of unconventional nozzles as part of the propulsion system. In this report, the Nuclear Thermal Rocket nozzle testing and evaluation program being conducted at the NASA Lewis Research Center is outlined and the advantages of a plug nozzle are described. A facility description, experimental designs and schematics are given. Results of pretest performance analyses show that high nozzle performance can be attained despite substantial nozzle length reduction through the use of plug nozzles as compared to a convergent-divergent nozzle. Pretest measurement uncertainty analyses indicate that specific impulse values are expected to be within plus or minus 1.17%.

  10. Segmented inlet nozzle for gas turbine, and methods of installation

    DOEpatents

    Klompas, Nicholas

    1985-01-01

    A gas turbine nozzle guide vane assembly is formed of individual arcuate nozzle segments. The arcuate nozzle segments are elastically joined to each other to form a complete ring, with edges abutted to prevent leakage. The resultant nozzle ring is included within the overall gas turbine stationary structure and secured by a mounting arrangement which permits relative radial movement at both the inner and outer mountings. A spline-type outer mounting provides circumferential retention. A complete rigid nozzle ring with freedom to "float" radially results. Specific structures are disclosed for the inner and outer mounting arrangements. A specific tie-rod structure is also disclosed for elastically joining the individual nozzle segments. Also disclosed is a method of assembling the nozzle ring subassembly-by-subassembly into a gas turbine employing temporary jacks.

  11. Design and experimental evaluation of a high temperature radial turbine with a moveable sidewall nozzle

    NASA Technical Reports Server (NTRS)

    Rogo, Casimir; Roelke, Richard J.

    1987-01-01

    The uncooled, 2.27 kg/sec mass flow radial turbine designed to operate at 1477 K in the gas generator of an advanced, variable-capacity 683 kW turboshaft engine was configured with a cooled, movable sidewall nozzle capable of changing the stage flow capacity from 50 to 100 percent of maximum. Overall performance test data were obtained in a turbine test rig that duplicated engine Reynolds numbers; attention is given to the changing of flow capacity by moving the hub or shroud sidewall, vane sidewall leakage, vaneless space sidewall geometry, and nozzle-cooling injection. Data are presented in the form of turbine flow, efficiency, work parameter, and performance mappings.

  12. Use of calophyllum inophyllum biofuel blended with diesel in DI diesel engine modified with nozzle holes and its size

    NASA Astrophysics Data System (ADS)

    Vairamuthu, G.; Sundarapandian, S.; Thangagiri, B.

    2016-05-01

    Improved thermal efficiency, reduction in fuel consumption and pollutant emissions from biodiesel fueled diesel engines are important issues in engine research. To achieve these, fast and perfect air-biodiesel mixing are the most important requirements. The mixing quality of biodiesel spray with air can be improved by better design of the injection system. The diesel engine tests were conducted on a 4-stroke tangentially vertical single cylinder (TV1) kirloskar 1500 rpm water cooled direct injection diesel engine with eddy current dynamometer. In this work, by varying different nozzles having spray holes of 3 (base, Ø = 0.280 mm), 4 (modified, Ø = 0.220 mm) and 5 (modified, Ø = 0.240 mm) holes, with standard static injection timing of 23° bTDC and nozzle opening pressure (NOP) of 250 bar maintained as constant throughout the experiment under steady state at full load condition of the engine. The effect of varying different nozzle configuration (number of holes), on the combustion, performance and exhaust emissions, using a blend of calophyllum inophyllum methyl ester by volume in diesel were evaluated. The test results showed that improvement in terms of brake thermal efficiency and specific fuel consumption for 4 holes and 5 holes nozzle operated at NOP 250 bar. Substantial improvements in the reduction of emissions levels were also observed for 5 holes nozzle operated at NOP 250 bar.

  13. Computational Fluid Dynamics Simulation of Dual Bell Nozzle Film Cooling

    NASA Technical Reports Server (NTRS)

    Braman, Kalen; Garcia, Christian; Ruf, Joseph; Bui, Trong

    2015-01-01

    Marshall Space Flight Center (MSFC) and Armstrong Flight Research Center (AFRC) are working together to advance the technology readiness level (TRL) of the dual bell nozzle concept. Dual bell nozzles are a form of altitude compensating nozzle that consists of two connecting bell contours. At low altitude the nozzle flows fully in the first, relatively lower area ratio, nozzle. The nozzle flow separates from the wall at the inflection point which joins the two bell contours. This relatively low expansion results in higher nozzle efficiency during the low altitude portion of the launch. As ambient pressure decreases with increasing altitude, the nozzle flow will expand to fill the relatively large area ratio second nozzle. The larger area ratio of the second bell enables higher Isp during the high altitude and vacuum portions of the launch. Despite a long history of theoretical consideration and promise towards improving rocket performance, dual bell nozzles have yet to be developed for practical use and have seen only limited testing. One barrier to use of dual bell nozzles is the lack of control over the nozzle flow transition from the first bell to the second bell during operation. A method that this team is pursuing to enhance the controllability of the nozzle flow transition is manipulation of the film coolant that is injected near the inflection between the two bell contours. Computational fluid dynamics (CFD) analysis is being run to assess the degree of control over nozzle flow transition generated via manipulation of the film injection. A cold flow dual bell nozzle, without film coolant, was tested over a range of simulated altitudes in 2004 in MSFC's nozzle test facility. Both NASA centers have performed a series of simulations of that dual bell to validate their computational models. Those CFD results are compared to the experimental results within this paper. MSFC then proceeded to add film injection to the CFD grid of the dual bell nozzle. A series of

  14. Jet-Surface Interaction: High Aspect Ratio Nozzle Test, Nozzle Design and Preliminary Data

    NASA Technical Reports Server (NTRS)

    Brown, Clifford; Dippold, Vance

    2015-01-01

    The Jet-Surface Interaction High Aspect Ratio (JSI-HAR) nozzle test is part of an ongoing effort to measure and predict the noise created when an aircraft engine exhausts close to an airframe surface. The JSI-HAR test is focused on parameters derived from the Turbo-electric Distributed Propulsion (TeDP) concept aircraft which include a high-aspect ratio mailslot exhaust nozzle, internal septa, and an aft deck. The size and mass flow rate limits of the test rig also limited the test nozzle to a 16:1 aspect ratio, half the approximately 32:1 on the TeDP concept. Also, unlike the aircraft, the test nozzle must transition from a single round duct on the High Flow Jet Exit Rig, located in the AeroAcoustic Propulsion Laboratory at the NASA Glenn Research Center, to the rectangular shape at the nozzle exit. A parametric nozzle design method was developed to design three low noise round-to-rectangular transitions, with 8:1, 12:1, and 16: aspect ratios, that minimizes flow separations and shocks while providing a flat flow profile at the nozzle exit. These designs validated using the WIND-US CFD code. A preliminary analysis of the test data shows that the actual flow profile is close to that predicted and that the noise results appear consistent with data from previous, smaller scale, tests. The JSI-HAR test is ongoing through October 2015. The results shown in the presentation are intended to provide an overview of the test and a first look at the preliminary results.

  15. Effect of Installation of Mixer/Ejector Nozzles on the Core Flow Exhaust of High-Bypass-Ratio Turbofan Engines

    NASA Technical Reports Server (NTRS)

    Harrington, Douglas E.

    1998-01-01

    The aerospace industry is currently investigating the effect of installing mixer/ejector nozzles on the core flow exhaust of high-bypass-ratio turbofan engines. This effort includes both full-scale engine tests at sea level conditions and subscale tests in static test facilities. Subscale model tests are to be conducted prior to full-scale testing. With this approach, model results can be analyzed and compared with analytical predications. Problem areas can then be identified and design changes made and verified in subscale prior to committing to any final design configurations for engine ground tests. One of the subscale model test programs for the integrated mixer/ejector development was a joint test conducted by the NASA Lewis Research Center and Pratt & Whitney Aircraft. This test was conducted to study various mixer/ejector nozzle configurations installed on the core flow exhaust of advanced, high-bypass-ratio turbofan engines for subsonic, commercial applications. The mixer/ejector concept involves the introduction of largescale, low-loss, streamwise vortices that entrain large amounts of secondary air and rapidly mix it with the primary stream. This results in increased ejector pumping relative to conventional ejectors and in more complete mixing within the ejector shroud. The latter improves thrust performance through the efficient energy exchange between the primary and secondary streams. This experimental program was completed in April 1997 in Lewis' CE-22 static test facility. Variables tested included the nozzle area ratio (A9/A8), which ranged from 1.6 to 3.0. This ratio was varied by increasing or decreasing the nozzle throat area, A8. Primary nozzles tested included both lobed mixers and conical primaries. These configurations were tested with and without an outer shroud, and the shroud position was varied by inserting spacers in it. In addition, data were acquired with and without secondary flow.

  16. Isolated Performance at Mach Numbers From 0.60 to 2.86 of Several Expendable Nozzle Concepts for Supersonic Applications

    NASA Technical Reports Server (NTRS)

    Re, Richard J.; Berrier, Bobby L.; Abeyounis, William K.

    2001-01-01

    Investigations have been conducted in the Langley 16-Foot Transonic Tunnel (at Mach numbers from 0.60 to 1.25) and in the Langley Unitary Plan Wind Tunnel (at Mach numbers from 2.16 to 2.86) at an angle of attack of 0 deg to determine the isolated performance of several expendable nozzle concepts for supersonic nonaugmented turbojet applications. The effects of centerbody base shape, shroud length, shroud ventilation, cruciform shroud expansion ratio, and cruciform shroud flap vectoring were investigated. The nozzle pressure ratio range, which was a function of Mach number, was between 1.9 and 11.8 in the 16-Foot Transonic Tunnel and between 7.9 and 54.9 in the Unitary Plan Wind Tunnel. Discharge coefficient, thrust-minus-drag, and the forces and moments generated by vectoring the divergent shroud flaps (for Mach numbers of 0.60 to 1.25 only) of a cruciform nozzle configuration were measured. The shortest nozzle had the best thrust-minus-drag performance at Mach numbers up to 0.95 but was approached in performance by other configurations at Mach numbers of 1.15 and 1.25. At Mach numbers above 1.25, the cruciform nozzle configuration having the same expansion ratio (2.64) as the fixed geometry nozzles had the best thrust-minus-drag performance. Ventilation of the fixed geometry divergent shrouds to the nozzle external boattail flow generally improved thrust-minus-drag performance at Mach numbers from 0.60 to 1.25, but decreased performance above a Mach number of 1.25.

  17. PDE Nozzle Optimization Using a Genetic Algorithm

    NASA Technical Reports Server (NTRS)

    Billings, Dana; Turner, James E. (Technical Monitor)

    2000-01-01

    Genetic algorithms, which simulate evolution in natural systems, have been used to find solutions to optimization problems that seem intractable to standard approaches. In this study, the feasibility of using a GA to find an optimum, fixed profile nozzle for a pulse detonation engine (PDE) is demonstrated. The objective was to maximize impulse during the detonation wave passage and blow-down phases of operation. Impulse of each profile variant was obtained by using the CFD code Mozart/2.0 to simulate the transient flow. After 7 generations, the method has identified a nozzle profile that certainly is a candidate for optimum solution. The constraints on the generality of this possible solution remain to be clarified.

  18. Advanced nozzle and engine components test facility

    NASA Technical Reports Server (NTRS)

    Beltran, Luis R.; Delroso, Richard L.; Delrosario, Ruben

    1992-01-01

    A test facility for conducting scaled advanced nozzle and engine component research is described. The CE-22 test facility, located in the Engine Research Building of the NASA Lewis Research Center, contains many systems for the economical testing of advanced scale-model nozzles and engine components. The combustion air and altitude exhaust systems are described. Combustion air can be supplied to a model up to 40 psig for primary air flow, and 40, 125, and 450 psig for secondary air flow. Altitude exhaust can be simulated up to 48,000 ft, or the exhaust can be atmospheric. Descriptions of the multiaxis thrust stand, a color schlieren flow visualization system used for qualitative flow analysis, a labyrinth flow measurement system, a data acquisition system, and auxiliary systems are discussed. Model recommended design information and temperature and pressure instrumentation recommendations are included.

  19. A nozzle internal performance prediction method

    NASA Technical Reports Server (NTRS)

    Carlson, John R.

    1992-01-01

    A prediction method was written and incorporated into a three-dimensional Navier-Stokes code (PAB3D) for the calculation of nozzle internal performance. The following quantities are calculated: (1) discharge coefficient; (2) normal, side, and axial thrust ratios; (3) rolling, pitching, and yawing moments; and (4) effective pitch and yaw vector angles. Four different case studies are presented to confirm the applicability of the methodology. Internal and, in most situations, external flow-field regions are required to be modeled. The computed nozzle discharge coefficient matches both the level and the trend of the experimental data within quoted experimental data accuracy (0.5 percent). Moment and force ratios are generally within 1 to 2 percent of the absolute level of experimental data, with the trends of data matched accurately.

  20. Nozzle designs with pitch precursor ablatives

    NASA Technical Reports Server (NTRS)

    Blevins, H. R.; Bedard, R. J.

    1976-01-01

    Recent developments in carbon phenolic ablatives for solid rocket motor nozzles have yielded a pitch precursor carbon fiber offering significant raw material availability and cost saving advantages as compared to conventional rayon precursor material. This paper discusses the results of an experimental program conducted to assess the thermal performance and characterize the thermal properties of pitch precursor carbon phenolic ablatives. The end result of this program is the complete thermal characterization of pitch fabric, pitch mat, hybrid pitch/rayon fabric and pitch mat molding compound. With these properties determined an analytic capability now exists for predicting the thermal performance of these materials in rocket nozzle liner applications. Further planned efforts to verify material performance and analytical prediction procedures through actual rocket motor firings are also discussed.

  1. Jet Engine Exhaust Nozzle Flow Effector

    NASA Technical Reports Server (NTRS)

    Turner, Travis L. (Inventor); Cano, Roberto J. (Inventor); Silcox, Richard J. (Inventor); Buehrle, Ralph D. (Inventor); Cagle, Christopher M. (Inventor); Cabell, Randolph H. (Inventor); Hilton, George C. (Inventor)

    2011-01-01

    A jet engine exhaust nozzle flow effector is a chevron formed with a radius of curvature with surfaces of the flow effector being defined and opposing one another. At least one shape memory alloy (SMA) member is embedded in the chevron closer to one of the chevron's opposing surfaces and substantially spanning from at least a portion of the chevron's root to the chevron's tip.

  2. Jet Engine Exhaust Nozzle Flow Effector

    NASA Technical Reports Server (NTRS)

    Turner, Travis L. (Inventor); Cano, Roberto J. (Inventor); Silox, Richard J. (Inventor); Buehrle, Ralph D. (Inventor); Cagle, Christopher M. (Inventor); Cabell, Randolph H. (Inventor); Hilton, George C. (Inventor)

    2014-01-01

    A jet engine exhaust nozzle flow effector is a chevron formed with a radius of curvature with surfaces of the flow effector being defined and opposing one another. At least one shape memory alloy (SMA) member is embedded in the chevron closer to one of the chevron's opposing surfaces and substantially spanning from at least a portion of the chevron's root to the chevron's tip.

  3. Wormhole Formation in RSRM Nozzle Joint Backfill

    NASA Technical Reports Server (NTRS)

    Stevens, J.

    2000-01-01

    The RSRM nozzle uses a barrier of RTV rubber upstream of the nozzle O-ring seals. Post flight inspection of the RSRM nozzle continues to reveal occurrence of "wormholes" into the RTV backfill. The term "wormholes", sometimes called "gas paths", indicates a gas flow path not caused by pre-existing voids, but by a little-understood internal failure mode of the material during motor operation. Fundamental understanding of the mechanics of the RSRM nozzle joints during motor operation, nonlinear viscoelastic characterization of the RTV backfill material, identification of the conditions that predispose the RTV to form wormholes, and screening of candidate replacement materials is being pursued by a joint effort between Thiokol Propulsion, NASA, and the Army Propulsion & Structures Directorate at Redstone Arsenal. The performance of the RTV backfill in the joint is controlled by the joint environment. Joint movement, which applies a tension and shear load on the material, coupled with the introduction of high pressure gas in combination create an environment that exceeds the capability of the material to withstand the wormhole effect. Little data exists to evaluate why the material fails under the modeled joint conditions, so an effort to characterize and evaluate the material under these conditions was undertaken. Viscoelastic property data from characterization testing will anchor structural analysis models. Data over a range of temperatures, environmental pressures, and strain rates was used to develop a nonlinear viscoelastic model to predict material performance, develop criteria for replacement materials, and quantify material properties influencing wormhole growth. Three joint simulation analogs were developed to analyze and validate joint thermal barrier (backfill) material performance. Two exploratory tests focus on detection of wormhole failure under specific motor operating conditions. A "validation" test system provides data to "validate" computer models and

  4. Method of making a rocket nozzle

    NASA Technical Reports Server (NTRS)

    Campbell, D. H. (Inventor)

    1969-01-01

    A method is described for forming the interior of a nozzle having uneven walls so that a throat of smooth converging and diverging sides is provided for passing flow. A metallic insert material is placed within the flow passageway adjacent to the area where the sharper throat constriction is to be formed, so that the material will flow through the inlet into the throat space when liquefied.

  5. Flow Separation Side Loads Excitation of Rocket Nozzle FEM

    NASA Technical Reports Server (NTRS)

    Smalley, Kurt B.; Brown, Andrew; Ruf, Joseph; Gilbert, John

    2007-01-01

    Modern rocket nozzles are designed to operate over a wide range of altitudes, and are also built with large aspect ratios to enable high efficiencies. Nozzles designed to operate over specific regions of a trajectory are being replaced in modern launch vehicles by those that are designed to operate from earth to orbit. This is happening in parallel with modern manufacturing and wall cooling techniques allowing for larger aspect ratio nozzles to be produced. Such nozzles, though operating over a large range of altitudes and ambient pressures, are typically designed for one specific altitude. Above that altitude the nozzle flow is 'underexpanded' and below that altitude, the nozzle flow is 'overexpanded'. In both conditions the nozzle produces less than the maximum possible thrust at that altitude. Usually the nozzle design altitude is well above sea level, leaving the nozzle flow in an overexpanded state for its start up as well as for its ground testing where, if it is a reusable nozzle such as the Space Shuttle Main Engine (SSME), the nozzle will operate for the majority of its life. Overexpansion in a rocket nozzle presents the critical, and sometimes design driving, problem of flow separation induced side loads. To increase their understanding of nozzle side loads, engineers at MSFC began an investigation in 2000 into the phenomenon through a task entitled "Characterization and Accurate Modeling of Rocket Engine Nozzle Side Loads", led by A. Brown. The stated objective of this study was to develop a methodology to accurately predict the character and magnitude of nozzle side loads. The study included further hot-fire testing of the MC-l engine, cold flow testing of subscale nozzles, CFD analyses of both hot-fire and cold flow nozzle testing, and finite element (fe.) analysis of the MC-1 engine and cold flow tested nozzles. A follow on task included an effort to formulate a simplified methodology for modeling a side load during a two nodal diameter fluid

  6. Nonequilibrium in a low power arcjet nozzle

    NASA Technical Reports Server (NTRS)

    Zube, Dieter M.; Myers, Roger M.

    1991-01-01

    Emission spectroscopy measurements were made of the plasma flow inside the nozzle of a 1 kW class arcjet thruster. The thruster propellant was a hydrogen-nitrogen mixture used to simulate fully decomposed hydrazine. The 0.25 mm diameter holes were drilled into the diverging section of the tungsten thruster nozzle to provide optical access to the internal flow. Atomic electron excitation, vibrational, and rotational temperatures were determined for the expanding plasma using relative line intensity techniques. The atomic excitation temperatures decreased from 18,000K at a location 3 mm downstream of the constrictor to 9,000K at a location 9 mm from the constrictor, while the molecular vibrational and rotational temperatures decreased from 6,500K to 2,500K and from 8,000K to 3,000K, respectively, between the same locations. The electron density measured using hydrogen H line Stark broadening decreased from about 10(exp 15) cm(-3) to about 2 times 10(exp 14) cm(-3) during the expansion. The results show that the plasma is highly nonequilibrium throughout the nozzle, with most relaxation times equal or exceeding the particle residence time.

  7. Oscillating combustion from a premix fuel nozzle

    SciTech Connect

    Richards, G.A.; Yip, M.J.

    1995-08-01

    Stringent emissions requirements for stationary gas turbines have produced new challenges in combustor design. In the past, very low NOx pollutant emissions have been achieved through various combustion modifications, such as steam or water injection, or post-combustion cleanup methods such as selective catalytic reduction (SCR). An emerging approach to NOx abatement is lean premix combustion. Lean premix combustion avoids the cost and operational problems associated with other NOx control methods. By premixing fuel and air at very low equivalence ratios, the high temperatures which produce NOx are avoided. The challenges of premix combustion include avoiding flashback, and ensuring adequate fuel/air premixing. In addition, the combustion must be stable. The combustor should not operate so close to extinction that a momentary upset will extinguish the flame (static stability), and the flame should not oscillate (dynamic stability). Oscillations are undesirable because the associated pressure fluctuations can shorten component lifetime. Unfortunately, experience has shown that premix fuel nozzles burning natural gas are susceptible to oscillations. Eliminating these oscillations can be a costly and time consuming part of new engine development. As part of the U.S. Department of Energy`s Advanced Turbine Systems Program, the Morgantown Energy Technology Center (METC) is investigating the issue of combustion oscillations produced by lean premix fuel nozzles. METC is evaluating various techniques to stabilize oscillating combustion in gas turbines. Tests results from a premix fuel nozzle using swirl stabilization and a pilot flame are reported here.

  8. RSRM Nozzle Anomalous Throat Erosion Investigation Overview

    NASA Technical Reports Server (NTRS)

    Clinton, R. G., Jr.; Wendel, Gary M.

    1998-01-01

    In September, 1996, anomalous pocketing erosion was observed in the aft end of the throat ring of the nozzle of one of the reusable solid rocket motors (RSRM 56B) used on NASA's space transportation system (STS) mission 79. The RSRM throat ring is constructed of bias tape-wrapped carbon cloth/ phenolic (CCP) ablative material. A comprehensive investigation revealed necessary and sufficient conditions for occurrence of the pocketing event and provided rationale that the solid rocket motors for the subsequent mission, STS-80, were safe to fly. The nozzles of both of these motors also exhibited anomalous erosion similar to, but less extensive than that observed on STS-79. Subsequent to this flight, the investigation to identify both the specific causes and the corrective actions for elimination of the necessary and sufficient conditions for the pocketing erosion was intensified. A detailed fault tree approach was utilized to examine potential material and process contributors to the anomalous performance. The investigation involved extensive constituent and component material property testing, pedigree assessments, supplier audits, process audits, full scale processing test article fabrication and evaluation, thermal and thermostructural analyses, nondestructive evaluation, and material performance tests conducted using hot fire simulation in laboratory test beds and subscale and full scale solid rocket motor static test firings. This presentation will provide an over-view of the observed anomalous nozzle erosion and the comprehensive, fault-tree based investigation conducted to resolve this issue.

  9. A study of the transmission characteristics of suppressor nozzles

    NASA Technical Reports Server (NTRS)

    Ahuja, K. K.; Salikuddin, M.; Burrin, R. H.; Plumbee, H. E., Jr.

    1980-01-01

    The internal noise radiation characteristics for a single stream 12 lobe 24 tube suppressor nozzle, and for a dual stream 36 chute suppressor nozzle were investigated. An equivalent single round conical nozzle and an equivalent coannular nozzle system were also tested to provide a reference for the two suppressors. The technique utilized a high voltage spark discharge as a noise source within the test duct which permitted separation of the incident, reflected and transmitted signals in the time domain. These signals were then Fourier transformed to obtain the nozzle transmission coefficient and the power transfer function. These transmission parameters for the 12 lobe, 24 tube suppressor nozzle and the reference conical nozzle are presented as a function of jet Mach number, duct Mach number polar angle and temperature. Effects of simulated forward flight are also considered for this nozzle. For the dual stream, 36 chute suppressor, the transmission parameters are presented as a function of velocity ratios and temperature ratios. Possible data for the equivalent coaxial nozzle is also presented. Jet noise suppression by these nozzles is also discussed.

  10. Fuel injection nozzle unit for internal combustion engines

    SciTech Connect

    Kushida, T.; Yamada, K.

    1987-01-20

    This patent describes a fuel injection nozzle unit for an internal combustion engine, including a nozzle body having injection holes and a pressure chamber formed therein, a nozzle needle fitted in the nozzle body and being liftable in the nozzle body to open the injection holes, a nozzle spring urging the nozzle needle in a direction of closing the injection holes, and a central plunger having one end thereof arranged opposite one end of the nozzle needle at a distance corresponding to a predetermined lift. The central plunger has another end face which is supplied with pressurized fuel, and the central plunger is liftable together with the nozzle needle against the pressure of the pressurized fuel when the predetermined lift is exceeded, the nozzle needle being lifted by a fuel pressure supplied to the pressure chamber to effect fuel injection. The improvement described here comprises: an annular-shaped, radially deformable piezo-electric element provided around the central plunger, the piezo-electric element having a substantially central hole therein which is penetrated by the central plunger; and means for selectively electrically energizing and deenergizing the piezo-electric element to selectively radially deform the piezo-electric element to thereby selectively reduce the diameter of the central hole thereof.

  11. Effect of the Thruster Configurations on a Laser Ignition Microthruster

    NASA Astrophysics Data System (ADS)

    Koizumi, Hiroyuki; Hamasaki, Kyoichi; Kondo, Ryo; Okada, Keisuke; Nakano, Masakatsu; Arakawa, Yoshihiro

    Research and development of small spacecraft have advanced extensively throughout the world and propulsion devices suitable for the small spacecraft, microthruster, is eagerly anticipated. The authors proposed a microthruster using 1—10-mm-size solid propellant. Small pellets of solid propellant are installed in small combustion chambers and ignited by the irradiation of diode laser beam. This thruster is referred as to a laser ignition microthruster. Solid propellant enables large thrust capability and compact propulsion system. To date theories of a solid-propellant rocket have been well established. However, those theories are for a large-size solid propellant and there are a few theories and experiments for a micro-solid rocket of 1—10mm class. This causes the difficulty of the optimum design of a micro-solid rocket. In this study, we have experimentally investigated the effect of thruster configurations on a laser ignition microthruster. The examined parameters are aperture ratio of the nozzle, length of the combustion chamber, area of the nozzle throat, and divergence angle of the nozzle. Specific impulse dependences on those parameters were evaluated. It was found that large fraction of the uncombusted propellant was the main cause of the degrading performance. Decreasing the orifice diameter in the nozzle with a constant open aperture ratio was an effective method to improve this degradation.

  12. Details of Side Load Test Data and Analysis for a Truncated Ideal Contour Nozzle and a Parabolic Contour Nozzle

    NASA Technical Reports Server (NTRS)

    Ruf, Joseph H.; McDaniels, David M.; Brown, Andrew M.

    2010-01-01

    Two cold flow subscale nozzles were tested for side load characteristics during simulated nozzle start transients. The two test article contours were a truncated ideal and a parabolic. The current paper is an extension of a 2009 AIAA JPC paper on the test results for the same two nozzle test articles. The side load moments were measured with the strain tube approach in MSFC s Nozzle Test Facility. The processing techniques implemented to convert the strain gage signals into side load moment data are explained. Nozzle wall pressure profiles for separated nozzle flow at many NPRs are presented and discussed in detail. The effect of the test cell diffuser inlet on the parabolic nozzle s wall pressure profiles for separated flow is shown. The maximum measured side load moments for the two contours are compared. The truncated ideal contour s peak side load moment was 45% of that of the parabolic contour. The calculated side load moments, via mean-plus-three-standard-deviations at each nozzle pressure ratio, reproduced the characteristics and absolute values of measured maximums for both contours. The effect of facility vibration on the measured side load moments is quantified and the effect on uncertainty is calculated. The nozzle contour designs are discussed and the impact of a minor fabrication flaw in the nozzle contours is explained.

  13. Star 48 solid rocket motor nozzle analyses and instrumented firings

    NASA Technical Reports Server (NTRS)

    Porter, R. L.

    1986-01-01

    The analyses and testing performed by NASA in support of an expanded and improved nozzle design data base for use by the U.S. solid rocket motor industry is presented. A production nozzle with a history of one ground failure and two flight failures was selected for analyses and testing. The stress analysis was performed with the Champion computer code developed by the U.S. Navy. Several improvements were made to the code. Strain predictions were made and compared to test data. Two short duration motor firings were conducted with highly instrumented nozzles. The first nozzle had 58 thermocouples, 66 strain gages, and 8 bondline pressure measurements. The second nozzle had 59 thermocouples, 68 strain measurements, and 8 bondline pressure measurements. Most of this instrumentation was on the nonmetallic parts, and provided significantly more thermal and strain data on the nonmetallic components of a nozzle than has been accumulated in a solid rocket motor test to date.

  14. Gas turbine nozzle vane insert and methods of installation

    DOEpatents

    Miller, William John; Predmore, Daniel Ross; Placko, James Michael

    2002-01-01

    A pair of hollow elongated insert bodies are disposed in one or more of the nozzle vane cavities of a nozzle stage of a gas turbine. Each insert body has an outer wall portion with apertures for impingement-cooling of nozzle wall portions in registration with the outer wall portion. The insert bodies are installed into the cavity separately and spreaders flex the bodies toward and to engage standoffs against wall portions of the nozzle whereby the designed impingement gap between the outer wall portions of the insert bodies and the nozzle wall portions is achieved. The spreaders are secured to the inner wall portions of the insert bodies and the bodies are secured to one another and to the nozzle vane by welding or brazing.

  15. Navier-Stokes predictions of multifunction nozzle flows

    NASA Technical Reports Server (NTRS)

    Wilmoth, Richard G.; Leavitt, Laurence D.

    1987-01-01

    A two-dimensional, Navier-Stokes code developed by Imlay based on the implicit, finite-volume method of MacCormack has been applied to the prediction of the flow fields and performance of several nonaxisymmetric, convergent-divergent nozzles with and without thrust vectoring. Comparisons of predictions with experiment show that the Navier-Stokes code can accurately predict both the flow fields and performance for nonaxisymmetric nozzles where the flow is predominantly two-dimensional and at nozzle pressure ratios at or above the design values. Discrepancies between predictions and experiment are noted at lower nozzle pressure ratios where separation typically occurs in portions of the nozzle. The overall trends versus parameters such as nozzle pressure ratio, flap angle, and vector angle were generally predicted correctly.

  16. Navier-Stokes predictions of multifunction nozzle flows

    NASA Astrophysics Data System (ADS)

    Wilmoth, Richard G.; Leavitt, Laurence D.

    1987-10-01

    A two-dimensional, Navier-Stokes code developed by Imlay based on the implicit, finite-volume method of MacCormack has been applied to the prediction of the flow fields and performance of several nonaxisymmetric, convergent-divergent nozzles with and without thrust vectoring. Comparisons of predictions with experiment show that the Navier-Stokes code can accurately predict both the flow fields and performance for nonaxisymmetric nozzles where the flow is predominantly two-dimensional and at nozzle pressure ratios at or above the design values. Discrepancies between predictions and experiment are noted at lower nozzle pressure ratios where separation typically occurs in portions of the nozzle. The overall trends versus parameters such as nozzle pressure ratio, flap angle, and vector angle were generally predicted correctly.

  17. Experimental investigation of shock-cell noise reduction for single-stream nozzles in simulated flight, comprehensive data report. Volume 3: Shadowgraph photos and facility description

    NASA Technical Reports Server (NTRS)

    Yamamoto, K.; Brausch, J. F.; Janardan, B. A.; Hoerst, D. J.; Price, A. O.; Knott, P. R.

    1984-01-01

    A total of 142 shadowgraph photographs were taken on 43 different plumes that were distributed over the six nozzle configurations using the 9.5 inch diameter collimated light beam of the shadowgraph setup. Aerodynamic flow conditions of the shadowgraph test points, the location and identification of each of the photographs, and copies of the pictures are presented.

  18. Quiet Clean Short-haul Experimental Engine (QCSEE) Under-The-Wing (UTW) boiler plate nacelle and core exhaust nozzle design report

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The mechanical design of the boiler plate nacelle and core exhaust nozzle for the QCSEE under the wing engine is presented. The nacelle, which features interchangeable hard-wall and acoustic panels, is to be utilized in the initial engine testing to establish acoustic requirements for the subsequent composite nacelle as well as in the QCSEE over the wing engine configuration.

  19. Mounting apparatus for a nozzle guide vane assembly

    DOEpatents

    Boyd, Gary L.; Shaffer, James E.

    1995-01-01

    The present invention provides a ceramic nozzle guide assembly with an apparatus for mounting it to a metal nozzle case that includes an intermediate ceramic mounting ring. The mounting ring includes a plurality of projections that are received within a plurality of receptacles formed in the nozzle case. The projections of the mounting ring are secured within the receptacles by a ceramic retainer that allows contact between the two components only along arcuate surfaces thus eliminating sliding contact between the components.

  20. Pressurizer with a mechanically attached surge nozzle thermal sleeve

    DOEpatents

    Wepfer, Robert M

    2014-03-25

    A thermal sleeve is mechanically attached to the bore of a surge nozzle of a pressurizer for the primary circuit of a pressurized water reactor steam generating system. The thermal sleeve is attached with a series of keys and slots which maintain the thermal sleeve centered in the nozzle while permitting thermal growth and restricting flow between the sleeve and the interior wall of the nozzle.

  1. Mounting apparatus for a nozzle guide vane assembly

    DOEpatents

    Boyd, G.L.; Shaffer, J.E.

    1995-09-12

    The present invention provides a ceramic nozzle guide assembly with an apparatus for mounting it to a metal nozzle case that includes an intermediate ceramic mounting ring. The mounting ring includes a plurality of projections that are received within a plurality of receptacles formed in the nozzle case. The projections of the mounting ring are secured within the receptacles by a ceramic retainer that allows contact between the two components only along arcuate surfaces thus eliminating sliding contact between the components. 8 figs.

  2. Fluidized-bed calciner with combustion nozzle and shroud

    DOEpatents

    Wielang, Joseph A.; Palmer, William B.; Kerr, William B.

    1977-01-01

    A nozzle employed as a burner within a fluidized bed is coaxially enclosed within a tubular shroud that extends beyond the nozzle length into the fluidized bed. The open-ended shroud portion beyond the nozzle end provides an antechamber for mixture and combustion of atomized fuel with an oxygen-containing gas. The arrangement provides improved combustion efficiency and excludes bed particles from the high-velocity, high-temperature portions of the flame to reduce particle attrition.

  3. Process modeling for carbon-phenolic nozzle materials

    NASA Technical Reports Server (NTRS)

    Letson, Mischell A.; Bunker, Robert C.; Remus, Walter M., III; Clinton, R. G.

    1989-01-01

    A thermochemical model based on the SINDA heat transfer program is developed for carbon-phenolic nozzle material processes. The model can be used to optimize cure cycles and to predict material properties based on the types of materials and the process by which these materials are used to make nozzle components. Chemical kinetic constants for Fiberite MX4926 were determined so that optimization of cure cycles for the current Space Shuttle Solid Rocket Motor nozzle rings can be determined.

  4. The regulation of flow through residual spray nozzles

    PubMed Central

    Lonergan, Richard P.; Hall, Lawrence B.

    1959-01-01

    Used residual spray nozzles, which have been discarded because of the increase in discharge rates, may be used again if their discharge rates are reduced by a metering orifice placed in the nozzle tip. A suitable orifice in a polyethylene disc is described. On the basis of laboratory test results, such a disc appears to be an inexpensive and satisfactory metering device for use in combination with worn spray nozzles. PMID:14418102

  5. Operational Dynamic Configuration Analysis

    NASA Technical Reports Server (NTRS)

    Lai, Chok Fung; Zelinski, Shannon

    2010-01-01

    Sectors may combine or split within areas of specialization in response to changing traffic patterns. This method of managing capacity and controller workload could be made more flexible by dynamically modifying sector boundaries. Much work has been done on methods for dynamically creating new sector boundaries [1-5]. Many assessments of dynamic configuration methods assume the current day baseline configuration remains fixed [6-7]. A challenging question is how to select a dynamic configuration baseline to assess potential benefits of proposed dynamic configuration concepts. Bloem used operational sector reconfigurations as a baseline [8]. The main difficulty is that operational reconfiguration data is noisy. Reconfigurations often occur frequently to accommodate staff training or breaks, or to complete a more complicated reconfiguration through a rapid sequence of simpler reconfigurations. Gupta quantified a few aspects of airspace boundary changes from this data [9]. Most of these metrics are unique to sector combining operations and not applicable to more flexible dynamic configuration concepts. To better understand what sort of reconfigurations are acceptable or beneficial, more configuration change metrics should be developed and their distribution in current practice should be computed. This paper proposes a method to select a simple sequence of configurations among operational configurations to serve as a dynamic configuration baseline for future dynamic configuration concept assessments. New configuration change metrics are applied to the operational data to establish current day thresholds for these metrics. These thresholds are then corroborated, refined, or dismissed based on airspace practitioner feedback. The dynamic configuration baseline selection method uses a k-means clustering algorithm to select the sequence of configurations and trigger times from a given day of operational sector combination data. The clustering algorithm selects a simplified

  6. Noise Benefits of Increased Fan Bypass Nozzle Area

    NASA Technical Reports Server (NTRS)

    Woodward, Richard P.; Hughes, Christopher E.

    2004-01-01

    An advanced model turbofan (typical of current engine technology) was tested in the NASA Glenn 9 by 15 Foot Low Speed Wind Tunnel (9-by 15-Foot LSWT) to explore far field acoustic effects of increased bypass nozzle area. This fan stage test was part of the NASA Glenn Fan Broadband Source Diagnostic Test, second entry (SDT2) which acquired aeroacoustic results over a range of test conditions. The baseline nozzle was sized to produce maximum stage performance for the engine at a high altitude, cruise point condition. However, the wind tunnel testing is conducted near sea level conditions. Therefore, in order to simulate and obtain performance at other aircraft operating conditions, two additional nozzles were designed and tested-one with a +5 percent increase in weight flow (+5.4 percent increase in nozzle area compared with the baseline nozzle), sized to simulate the performance at the stage design point conditions, and the other with a +7.5 percent increase in weight flow (+10.9 percent increase in nozzle area), sized for maximum weight flow with a fixed nozzle at sea level conditions. Measured acoustic benefits with increased nozzle area were very encouraging, showing overall sound power level (OAPWL) reductions of 2 or more dB while the stage thrust actually increased by several percentage points except fro the most open nozzle at takeoff rotor speed where stage performance decreased. These noise reduction benefits were seen to primarily affect broadband noise, and were evident throughout the range of measured sideline angles.

  7. Supersonic jet noise reduction by coaxial rectangular nozzles

    NASA Technical Reports Server (NTRS)

    Ahuja, K. K.; Manes, J. P.; Massey, K. C.

    1992-01-01

    A physical understanding of noise reduction mechanisms in supersonic, single, and coaxial rectangular jets is quantified and obtained, with emphasis on shock noise reduction. For all conditions, corresponding acoustic measurements for an equivalent round jet are also obtained so that the noise characteristics of the two types of jets can be compared directly to quantify the noise reductions. Comparisons are thus provided for a single rectangular nozzle vs a single equivalent round nozzle, and a coaxial rectangular nozzle vs an equivalent round nozzle. It is shown that different operating conditions and nozzle arrangements for the same thrust, total exit area, and mass flow rate can produce different noise levels. With at least one stream operated supersonically, the coaxial rectangular nozzle operated in the inverted-velocity profile is always quieter than in the normal velocity profile mode for the same thrust, exit area, and mass flow rate. In general, the coaxial rectangular nozzle is shown to be quieter than an equivalent circular nozzle only for those conditions for which both nozzles are operated supersonically.

  8. Erosion resistant nozzles for laser plasma extreme ultraviolet (EUV) sources

    DOEpatents

    Kubiak, Glenn D.; Bernardez, II, Luis J.

    2000-01-04

    A gas nozzle having an increased resistance to erosion from energetic plasma particles generated by laser plasma sources. By reducing the area of the plasma-facing portion of the nozzle below a critical dimension and fabricating the nozzle from a material that has a high EUV transmission as well as a low sputtering coefficient such as Be, C, or Si, it has been shown that a significant reduction in reflectance loss of nearby optical components can be achieved even after exposing the nozzle to at least 10.sup.7 Xe plasma pulses.

  9. Computer program for natural gas flow through nozzles

    NASA Technical Reports Server (NTRS)

    Johnson, R. C.

    1972-01-01

    Subroutines, FORTRAN 4 type, were developed for calculating isentropic natural gas mass flow rate through nozzle. Thermodynamic functions covering compressibility, entropy, enthalpy, and specific heat are included.

  10. Flow separation in rocket nozzles under high altitude condition

    NASA Astrophysics Data System (ADS)

    Stark, R.; Génin, C.

    2016-03-01

    The knowledge of flow separation in rocket nozzles is crucial for rocket engine design and optimum performance. Typically, flow separation is studied under sea-level conditions. However, this disregards the change of the ambient density during ascent of a launcher. The ambient flow properties are an important factor concerning the design of altitude-adaptive rocket nozzles like the dual bell nozzle. For this reason an experimental study was carried out to study the influence of the ambient density on flow separation within conventional nozzles.

  11. Variable volume combustor with aerodynamic fuel flanges for nozzle mounting

    DOEpatents

    McConnaughhay, Johnie Franklin; Keener, Christopher Paul; Johnson, Thomas Edward; Ostebee, Heath Michael

    2016-09-20

    The present application provides a combustor for use with a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles and a fuel injection system for providing a flow of fuel to the micro-mixer fuel nozzles. The fuel injection system may include a number of support struts supporting the fuel nozzles and for providing the flow of fuel therethrough. The fuel injection system also may include a number of aerodynamic fuel flanges connecting the micro-mixer fuel nozzles and the support struts.

  12. Experimental study of subsonic microjet escaping from a rectangular nozzle

    NASA Astrophysics Data System (ADS)

    Aniskin, V. M.; Maslov, A. A.; Mukhin, K. A.

    2016-10-01

    The first experiments on the subsonic laminar microjets escaping from the nozzles of rectangular shape are carried out. The nozzle size is 83.3x3823 microns. Reynolds number calculated by the nozzle height and the average flow velocity at the nozzle exit ranged from 58 to 154. The working gas was air at room temperature. The velocity decay and velocity fluctuations along the center line of the jet are determined. The fundamental difference between the laminar microjets characteristics and subsonic turbulent jets of macro size is shown. Based on measurements of velocity fluctuations it is shown the presence of laminar-turbulent transition in microjets and its location is determined.

  13. Analysis of Nozzle Jet Plume Effects on Sonic Boom Signature

    NASA Technical Reports Server (NTRS)

    Bui, Trong

    2010-01-01

    An axisymmetric full Navier-Stokes computational fluid dynamics (CFD) study was conducted to examine nozzle exhaust jet plume effects on the sonic boom signature of a supersonic aircraft. A simplified axisymmetric nozzle geometry, representative of the nozzle on the NASA Dryden NF-15B Lift and Nozzle Change Effects on Tail Shock (LaNCETS) research airplane, was considered. The highly underexpanded nozzle flow is found to provide significantly more reduction in the tail shock strength in the sonic boom N-wave pressure signature than perfectly expanded and overexpanded nozzle flows. A tail shock train in the sonic boom signature, similar to what was observed in the LaNCETS flight data, is observed for the highly underexpanded nozzle flow. The CFD results provide a detailed description of the nozzle flow physics involved in the LaNCETS nozzle at different nozzle expansion conditions and help in interpreting LaNCETS flight data as well as in the eventual CFD analysis of a full LaNCETS aircraft. The current study also provided important information on proper modeling of the LaNCETS aircraft nozzle. The primary objective of the current CFD research effort was to support the LaNCETS flight research data analysis effort by studying the detailed nozzle exhaust jet plume s imperfect expansion effects on the sonic boom signature of a supersonic aircraft. Figure 1 illustrates the primary flow physics present in the interaction between the exhaust jet plume shock and the sonic boom coming off of an axisymmetric body in supersonic flight. The steeper tail shock from highly expanded jet plume reduces the dip of the sonic boom N-wave signature. A structured finite-volume compressible full Navier-Stokes CFD code was used in the current study. This approach is not limited by the simplifying assumptions inherent in previous sonic boom analysis efforts. Also, this study was the first known jet plume sonic boom CFD study in which the full viscous nozzle flow field was modeled, without

  14. Water distribution characteristics of spray nozzles in a cooling tower

    NASA Astrophysics Data System (ADS)

    Vitkovic, Pavol

    2015-05-01

    Water distribution characteristics of spray nozzles with spray plates used to distribute cooling water to the cooling fills in a cooling tower is one of the important parameters for the selection of nozzles. Water distribution characteristic describes the distribution of water from the axis of the nozzle along a fill. One of the parameters affecting the water distribution characteristic of the nozzle is airflow velocity of counter flow airstream. Water distribution characteristics are commonly measured using by a set of containers. The problem with this method of the measurement of characteristics is block of the airflow with collections of containers. Therefore, this work is using the visualization method.

  15. Development of a Jet Noise Prediction Method for Installed Jet Configurations

    NASA Technical Reports Server (NTRS)

    Hunter, Craig A.; Thomas, Russell H.

    2003-01-01

    This paper describes development of the Jet3D noise prediction method and its application to heated jets with complex three-dimensional flow fields and installation effects. Noise predictions were made for four separate flow bypass ratio five nozzle configurations tested in the NASA Langley Jet Noise Laboratory. These configurations consist of a round core and fan nozzle with and without pylon, and an eight chevron core nozzle and round fan nozzle with and without pylon. Predicted SPL data were in good agreement with experimental noise measurements up to 121 inlet angle, beyond which Jet3D under predicted low frequency levels. This is due to inherent limitations in the formulation of Lighthill's Acoustic Analogy used in Jet3D, and will be corrected in ongoing development. Jet3D did an excellent job predicting full scale EPNL for nonchevron configurations, and captured the effect of the pylon, correctly predicting a reduction in EPNL. EPNL predictions for chevron configurations were not in good agreement with measured data, likely due to the lower mixing and longer potential cores in the CFD simulations of these cases.

  16. View of a pallet configured to support 51-A satellite-retrieval mission

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A high angle view of a Spacelab type pallet configured to support NASA's 51-A satellite-retrieval mission. At left are two capture devices called 'stingers' used to enter the communications satellites at the nozzle of the spent engine. Center are circular areas for clamping down and securing the satellites for the remainder of the trip.

  17. An MDOE Assessment of Nozzle Vanes for High Bypass Ratio Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda; Norum, Thomas; Bridges, James

    2006-01-01

    The effect of airfoil-shaped vanes placed in the fan stream of a BPR 8 coannular nozzle model system on the resulting jet noise was investigated. The experiments used a Modern Design of Experiments approach to investigate the impact of a range of vane parameters on the noise reduction achieved at representative takeoff conditions. The experimental results showed that the installation of the vanes decreased low frequency noise radiation in the downstream peak-noise direction and increased high frequency noise in the upstream direction. Results also showed that improper selection of the vane configuration resulted in increased low frequency noise radiation in the upstream direction. Large angles of attack are shown to reduce noise near the peak jet noise angle and increase noise in the upstream direction. The MDOE analysis yields an optimum design that minimizes perceived noise levels. Limited data taken with a BPR 5 nozzle system showed that the vanes result in better effective perceived noise reduction for lower bypass ratio nozzles than for the BPR 8 model.

  18. Development of Schlieren Imaging for Analysis of Supersonic Complex Multi-stream Rectangular Nozzle

    NASA Astrophysics Data System (ADS)

    Coleman, Thomas; Berry, Matthew; Magstadt, Andrew; Gogineni, Sivaram; Glauser, Mark; Skytop Turbulence Laboratories Team; Spectral Energies LLC. Collaboration

    2015-11-01

    A schlieren apparatus has been installed to provide the shock structure of the flow in a supersonic complex multi-stream rectangular jet nozzle. The schlieren images collected are being used for analysis which is paired with unsteady pressure data taken simultaneously, both of which complement PIV data taken in same facility. The schlieren setup is of Herschellian z-type configuration aligned vertically and perpendicular to the nozzle exit. By making use of large twin parabolic mirrors, a 12.5 inch diameter test window has been achieved, capable of capturing the evolution of shock cells from development to collapse. An LED light source was used with its driver circuit to allow for controlled microsecond pulses for collecting time resolved schlieren. Schlieren results to date indicate that there is a shock train arising inside the nozzle and persisting downstream that is quasi steady. This has also been observed in simulations. The shock structure appears to have a dominant effect in that they localize and provide the skeleton for the other flow structures, affecting and being affected by the adjacent shear layers. We would like to acknowledge SBIR Phase 2 with Spectral Energies under direction of Barry Kiel (Program Manager).

  19. Numerical Study and Performance Evaluation for Pulse Detonation Engine with Exhaust Nozzle

    NASA Astrophysics Data System (ADS)

    Kimura, Yuichiro; Tsuboi, Nobuyuki; Hayashi, A. Koichi; Yamada, Eisuke

    This paper presents the propulsive performance evaluation for the H2/Air Pulse Detonation Engine (PDE) with a converging-diverging exhaust nozzle by the system-level modeling and multi-cycle numerical simulations. This study deals with the two-dimensional and axisymmetric compressible Euler equations with a detail chemical reaction model. First, single-shot propulsive performance of simplified-PDE, which is without exhaust nozzle, is evaluated to show the validity of the numerical and performance evaluation method. The influences of the initial conditions, ignition energy, grid resolution, and scale effects on the propulsive performance are studied with the multi-cycle simulations. The present results are compared with the results calculated by Ma et al. and Harris et al. and the difference between their results and the present simulations are approximately 2-3% because their chemical reactions use one-step model with one-γ model. The effects of the specific heat ratio should be estimated for various nozzle configurations and flight conditions.

  20. DONBOL: A computer program for predicting axisymmetric nozzle afterbody pressure distributions and drag at subsonic speeds

    NASA Technical Reports Server (NTRS)

    Putnam, L. E.

    1979-01-01

    A Neumann solution for inviscid external flow was coupled to a modified Reshotko-Tucker integral boundary-layer technique, the control volume method of Presz for calculating flow in the separated region, and an inviscid one-dimensional solution for the jet exhaust flow in order to predict axisymmetric nozzle afterbody pressure distributions and drag. The viscous and inviscid flows are solved iteratively until convergence is obtained. A computer algorithm of this procedure was written and is called DONBOL. A description of the computer program and a guide to its use is given. Comparisons of the predictions of this method with experiments show that the method accurately predicts the pressure distributions of boattail afterbodies which have the jet exhaust flow simulated by solid bodies. For nozzle configurations which have the jet exhaust simulated by high-pressure air, the present method significantly underpredicts the magnitude of nozzle pressure drag. This deficiency results because the method neglects the effects of jet plume entrainment. This method is limited to subsonic free-stream Mach numbers below that for which the flow over the body of revolution becomes sonic.