| A Thermodynamically Complete Model for One-Dimensional Two-Phase Flows With Heat Exchange |
MAY 2006 |
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| Authors:
A. D. Resnyansky; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION EDINBURGH (AUSTRALIA)
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 | This publication reports on a compact presentation of a one-dimensional model for the description of two-phase flows with heat exchange. This model was proposed earlier in the form of a system of equations, containing the heat conduction and entropy conservation equations for each phase. In this report the system is formulated in a form that is consistent with the formulation of the preceding report of the author. The present system ... |
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| Spatially-Resolved Temperature Diagnostic for Supersonic Flow Using Cross-Beam Doppler-Limited Laser Saturation Spectroscopy |
MAR 2006 |
185 pages |
| Authors:
Grady T. Phillips; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
 | Optical techniques for measuring the temperature in three-dimensional supersonic reactive flows have typically depended on lineshape measurements using single-beam laser absorption spectroscopy. However, absorption over extended path lengths in flows with symmetric, turbulent eddies can lead to systematically high extracted temperatures due to Doppler shifts resulting from flow along the absorption path. To eliminate these problems, Cross-Beam Saturation Absorption Spectroscopy (CBSAS) and Cross-Beam Inter-Modulated Fluorescence (CBIMF) have been developed which ... |
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| DSMC Convergence Behavior for Fourier Flow |
13 JUL 2005 |
7 pages |
| Authors:
D. J. Radar; M. A. Gallis; J. R. Torczynski; W. Wagner; SANDIA NATIONAL LABS ALBUQUERQUE NM
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| The convergence behavior of Bird's Direct Simulation Monte Carlo (DSMC) method is explored for near-continuum, one-dimensional Fourier flow. An argon-like, hard-sphere gas is confined between two parallel, fully accommodating, motionless walls of unequal temperature. The simulations are performed using a one-dimensional code based on Bird's DSMC prescription. The convergence metric is taken as the ratio of the DSMC-calculated bulk thermal conductivity to the infinite-approximation, Chapman-Enskog (CE) theoretical value. The convergence ... |
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| Numerical Study of Essentially Unsteady Evaporation |
13 JUL 2005 |
7 pages |
| Authors:
V. A. Titarev; E. M. Shakhov; TRENTO UNIV (ITALY)
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| We study numerically, essentially unsteady evaporation and heat transfer of a rarefied gas using the S-model kinetic equation. Three particular cases are considered: one-dimensional flow from a flat surface and purely radial flows from the surface of a cylinder or a sphere. We present numerical results for different values of the evaporation coefficient and saturated vapor density which demonstrate the strong dependence of the flow on these two parameters. |
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| A Model for Thermal Decomposition of Hydrogen Peroxide |
JUL 2004 |
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| Authors:
S. D. Heister; W. E. Anderson; J. H. Corpening; B. L. Austin; PURDUE UNIV LAFAYETTE IN SCHOOL OF AERONAUTICS AND ASTRONAUTICS
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| A one-dimensional model has been developed to investigate the thermal decomposition of rocket grade hydrogen peroxide (HP) in a stream of previously decomposed HP products. The model developed assumes steady, one-dimensional adiabatic flow and includes basic mass balances, droplet evaporation, gas-phase decomposition kinetics, droplet dynamics, and control volume conservation laws. The code is adjustable for HP percent concentration for both main and secondary flows, massflow rates for both flows, and ... |
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| Transport in Plasma Thrusters Using Complex Propellants |
01 MAR 2004 |
80 pages |
| Authors:
Peter J. Turchi; OHIO STATE UNIV COLUMBUS DEPT OF AEROSPACE ENGINEERING APPLIED MECHANICS ANDAVIATION
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| Theoretical modeling of ablation-fed, pulsed plasma thrusters (PPTs) with the MACH2 code has shown that after repeated pulsed operation, the total expelled mass is due to ablation during the discharge and solid decomposition that persists long after the pulse. The latter mass does not considerably contribute to the impulse-bit thus degrading thruster performance. For the rectangular PPT geometry, optimizing current waveforms in combination with channel widths are presented, that utilize ... |
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| Wave Bottom Boundary Layer Models for Smooth and Rough Beds |
17 SEP 2003 |
22 pages |
| Authors:
Jack Puleo; Oleg Mouraenko; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
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| Seven one-dimensional wave bottom boundary layer models have been analyzed based on different methods for estimating the turbulent eddy viscosity (laminar, linear, linear-exponential, parabolic. k-one-equation turbulence closure, k-epsilon-two-equation turbulence closure, and k-omega-two-equation turbulence closure). Two generic test cases displayed similar velocity profiles for all (he models with the exception of the laminar model. Boundary layer and sheer stress estimates, however, did show some differences. The linear and parabolic models predicted ... |
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| Analysis of Boundary Conditions for Factorizable Discretizations of the Euler Equations |
MAY 2002 |
30 pages |
| Authors:
Boris Diskin; James L. Thomas; INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA
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| In this article, several sets of boundary conditions or factorizable schemes corresponding to the steady-state compressible Euler equations are evaluated. The analyzed model is a one-dimensional constant-coefficient problem. Numerical tests have been performed for a fully subsonic quasi-one-dimensional flow in a convergent/divergent channel. This paper focuses on the effect of boundary-condition equations on stability and accuracy of the discrete solutions. Explicit correspondence between solutions and boundary conditions is established through ... |
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| A Model Predictor for Chemical Laser Combustors |
15 DEC 2001 |
17 pages |
| Authors:
M. A. Kwok; AEROSPACE CORP EL SEGUNDO CA
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| This spreadsheet model attempts to replicate many of the empirical features observed in HF chemical laser combustors, or gain generators, from time-start. The model, dubbed HYFLAME, is constructed from control volume analyses of the combustor vessel that are described by modules depicting the simplified combustion thermochemistry, fluid mechanics for one-dimensional steady nozzle flow, chemical kinetics in frozen flow, simplified heat transfer analyses, and a simple thermal-structural model. Model outputs include ... |
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| Structure-Based Turbulence Model |
30 OCT 2000 |
4 pages |
| Authors:
W. C. Reynolds; STANFORD UNIV CA DEPT OF MECHANICAL ENGINEERING
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| During the period of this award, the basic structure-based model for rapid distortions of homogeneous turbulence was extended to deal with slow distortions and inhomogeneities. A computer program was written to study the extended model in various one-dimensional flows, including channel flows with frame rotation and transpiration. The model was in-stalled in NASA's INS2D code for generalized flow analysis. The rapid distortion versions of both ... |
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| Analytical Solutions for the Unsteady Compressible Flow Equations Serving as Test Cases for the Verification of Numerical Schemes |
01 OCT 2000 |
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| Authors:
S. Tsangaris; T. Pappou; NATO RESEARCH AND TECHNOLOGY ORGANIZATION NEUILLY-SUR-SEINE (FRANCE)
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| The verification of numerical schemes for solving the equations of inviscid and viscous compressible unsteady flow equations is limited to a small number of analytical solutions of the equations governing the one-dimensional unsteady flow including moving discontinuities. Among them the most important were given first by B Riemann (1859.1860) and later by W.J.M RanKine (1870), P.H. Hugoniot (1887), Lord Rayleigh (1910) and GI. Taylor (1910). The scope of the present ... |
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| A One-Dimensional Atmospheric Boundary Layer Model: Comparison with Observations |
SEP 2000 |
31 pages |
| Authors:
Arnold Tunick; ARMY RESEARCH LAB ADELPHI MD
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| This report examines details of a one-dimensional (1D) atmospheric boundary layer model to establish the proper functioning of its soil, plant, and atmospheric physics. To achieve this goal, I inspect, repair, and modify a computer program that scientists at the Hebrew University, Department of Soil and Water Sciences, gave to me years ago. The computer program was exercised to determine if the model results are stable ... |
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| The Role of Transverse Flow in Co-Injection Resin Transfer Molding |
DEC 1999 |
39 pages |
| Authors:
Bruce K. Fink; Emanuele F. Gillio; Surresh G. Advani; John W. Gillespie Jr.; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| A co-injection resin transfer molding (CIRTM) process has been developed at the U.S. Army Research Laboratory (ARL) in collaboration with the University of Delaware. It enables two or more resins to be simultaneously injected into a mold filled with a stationary fiber preform. This process allows for the manufacturing of cocured multilayer multiresin structures in a single processing step. A separation layer is used to provide ... |
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| Thermal Damage and Shear Failure of Chromium Plated Coating on an A723 Steel Cannon Tube |
JUL 1999 |
23 pages |
| Authors:
John H. Underwood; Anthony P. Parker; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER WATERVLIET NY BENET WEAPONS LAB
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| Degradation of the electroplated chromium coating at the bore of A723 steel cannon barrels is characterized here following cannon firing and used to model the coating failure process. Transient thermal stresses due to firing are calculated using one-dimensional heat flow analysis and used as input to a shear failure model of the coating/substrate couple. The cracking array that develops in the coating and substrate with repeated thermal cycles, the configuration ... |
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| Second Report for Research and Modeling of Water Particles in Adverse Weather Simulation Facilities |
JUL 1998 |
139 pages |
| Authors:
R. J. Schulz; ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFS TN
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| This report describes a continuation of research into the modeling ofwater particle freezing for application to adverse weather simulation facilities. The research was initiated in FYI 996 to investigate the physics of freezing of submillimeter supercooled water particles or droplets in both natural and artificial or simulated adverse weather environments. The first phase of the research was reported and discussed in a report 1 and a paper 2. The work ... |
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| Unsteady Ice Jam Processes |
DEC 97 |
93 pages |
| Authors:
Jon E. Zufelt; Robert Ettema; COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
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| Ice jams cause flooding in northern temperate climate areas, usually forming rapidly, often with little warning, constricting water flow and elevating water levels. Consequently, jam formation comprises highly unsteady processes: drifting ice pieces are brought to rest, accumulated ice shoves and thickens, and initial water depths and velocities change. Those processes are even more unsteady when a jam collapses. Prior simulations of ice jams, however, treat them as simply stationary, ... |
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| COSFLOW: A Finite Element Model Coupling One-Dimensional Canal, Two- Dimensional Overland, and Three-Dimensional Subsurface Flow |
SEP 97 |
200 pages |
| Authors:
Gour-Tsyh Yeh; Jing-Ru Cheng; Ming-Hsu Li; Hwai- Ping Cheng; Hsin-Chi J. Lin; ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS COASTAL HYDRAULICS LA B
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| This report presents the user's manual of COSFLOW, which is a three- dimensional Finite Element Model coupling one-dimensional (1-D) Canal, two- dimensional (2-D) Overland, and three-dimensional (3-D) Subsurface Flow. The 1-D channel flow is described by water budget under the assumption that equilibrium within each channel reach is achieved instantaneously. The 2-D overland flow is modeled with a diffusive wave approach. Retention ponds included in the overland flow are simulated ... |
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| Adaptation of a Three-Dimensional Numerical Simulation to Represent Gas Turbine Engine Compression Systems |
APR 97 |
86 pages |
| Authors:
Jacqueline C. Chalk; SVERDRUP TECHNOLOGY INC ARNOLD AFS TN
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| A new three-dimensional compression system simulation was constructed by coupling the three-dimensional Navier Stokes flow solver, NPARC, with source terms that model the effects of turbomachinery components. A stage by stage characteristic technique adapted from the one-dimensional compressor code, DYNTECC, was used to calculate the turbomachinery source terms. This report discusses the development, adaptation, and implementation of the stage characteristic approach for calculating sources used in NPARC. The distribution of ... |
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| A One-Dimensional Numerical Method for Simulating Multiple Stage Shock Tube Flows |
NOV 96 |
57 pages |
| Authors:
Stephen J. Schraml; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| A method is presented for the numerical simulation of time-dependent fluid flow in shock tubes and blast simulators. This method solves the Euler equations in a one-dimensional (1-D) computational domain with area changes. Complex flow fields can be simulated through the use of grid geometries and boundary conditions that are allowed to vary with time. The formulation of the solution algorithm and the time-varying boundary conditions are described. Results of ... |
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| UNET: One-Dimensional Unsteady Flow Through a Full Network of Open Channels. User's Manual |
JUL 96 |
288 pages |
| Authors:
Robert L. Barkau; HYDROLOGIC ENGINEERING CENTER DAVIS CA
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| UNET is a numerical model that simulates one dimensional unsteady flow through a full network of open channels. In addition to solving the network system, UNET provides the user with the ability to apply many external and internal boundary conditions, including: flow and stage hydrographs, rating curves, gated and uncontrolled spillways, pump stations, bridges, culverts, and levee systems. |
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| Development and Evolution of Nearshore Topography |
17 OCT 95 |
4 pages |
| Authors:
Bradley T. Werner; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
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| Hydrodynamic descriptions of one-dimensional granular systems have emphasized that the usual master variables, density, velocity and temperature are inadequate. A minimal description requires a fourth variable which is the third moment or "skewness" of the single particle velocity distribution function. These supplemented hydrodynamic systems have been used to study the linear stability of the spatially homogeneous state and good agreement with numerical simulation ... |
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| An Analytical Solution for the Unsteady Flow of a Bingham Plastic Fluid In a Circular Tube |
17 OCT 95 |
32 pages |
| Authors:
Stephen A. Austin; NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV RI
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| This report describes a closed form solution of the axial velocity profile and the shear stress profile for a Bingham plastic fluid in a circular tube. The analysis simulates the commencement of flow resulting from a pressure gradient. Past numerical and analytical solutions are shown to be deficient in the early stages of the flow when they are compared with the closed form solution presented here. |
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| Efficient Implementation of Weighted ENO Schemes |
OCT 95 |
42 pages |
| Authors:
Guang-Shan Jiang; Chi-Wang Shu; INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA
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| In this paper, we further analyze, test, modify and improve the high order WENO (weighted essentially non-oscillatory) finite difference schemes of Liu, Osher and Chan 9. It was shown by Liu et al. that WENO schemes constructed from the r(th) order (in L(1) norm) ENO schemes are (r + 1)th order accurate. We propose a new way of measuring the smoothness of a numerical solution, emulating the idea of minimizing ... |
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| HEC-RAS River Analysis System. Hydraulic User's Manual. Version 1.0 |
JUL 95 |
168 pages |
| Authors:
Gary W. Brunner; HYDROLOGIC ENGINEERING CENTER DAVIS CA
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| Welcome to the Hydrologic Engineering Center's River Analysis System (HEC-RAS). This software allows you to perform one-dimensional steady flow, unsteady flow, and sediment transport calculations (The current version of HEC- RAS can only perform steady flow calculations. Unsteady flow and sediment transport will be added in future versions). The HEC-RAS modeling system was developed as a part of the Hydrologic Engineering Center's 'Next Generation' (NexGen) of hydrologic engineering software. The ... |
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| HEC-RAS River Analysis System. Hydraulic Reference Manual. Version 1.0 |
JUL 95 |
143 pages |
| Authors:
Gary W. Brunner; HYDROLOGIC ENGINEERING CENTER DAVIS CA
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| Welcome to the Hydrologic Engineering Center's River Analysis System (HEC-RAS). This software allows you to perform one-dimensional steady flow, unsteady flow, and sediment transport calculations. The current version of HEC- RAS only supports one-dimensional, steady flow, water surface profile calculations. This manual specifically documents the hydraulic capabilities of the Steady flow portion of HEC-RAS. Documentation for unsteady flow and sediment transport calculations will be made available as these features are ... |
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| Monte-Carlo Simulation Methods for Finite Flat Plate Winding Flows |
15 NOV 94 |
18 pages |
| Authors:
Yuzhong Shi; Qifen Wu; Bing Ren; NATIONAL AIR INTELLIGENCE CENTER WRIGHT-PATTERSON AFB OH
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| This article opts for the use of direct simulation Monte-Carlo methods to solve such problems as those associated with winding flows around flat plates of finite length. The methods in question are ones which go through tracking the movements of simulated molecules by computer in order to realize numerical value simulations. Collision calculations between simulated molecules are determined from statistical samplings. As far as collision models are concerned, respective selections ... |
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| Dynamic Response of a Compressor Research Facility |
DEC 93 |
226 pages |
| Authors:
Janet W. Grondin; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
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| The response of the Wright Laboratory Compressor Research Facility to a small amplitude, acoustic, sinusoidal disturbance was investigated. The fluid transmission line equations for laminar, one-dimensional flow in a circular duct were solved and verified through a laboratory experiment using a scale model of the facility. The resonant frequencies of the facility were determined for a variety of flow conditions. Techniques for analytically modeling end impedance and flow straightening elements ... |
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| Shape Optimization Governed by the Euler Equations Using an Adjoint Method |
NOV 93 |
21 pages |
| Authors:
Angelo Iollo; Manuel D. Salas; Shlomo Taasan; INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA
|
| In this paper we discuss a numerical approach for the treatment of optimal shape problems governed by the Euler equations. In particular, we focus on flows with embedded shocks. We consider a very simple problem: the design of a quasi-one-dimensional Laval nozzle. We introduce a cost function and a set of Lagrange multipliers to achieve the minimum. The nature of the resulting costate equations is discussed. A theoretical difficulty that ... |
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| Formulation of a Next-Generation Interior Ballistic Code |
OCT 93 |
71 pages |
| Authors:
Paul S. Gough; GOUGH (PAUL) ASSOCIATES INC PORTSMOUTH NH
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| Two-phase flow interior ballistic codes, both one-dimensional and two-dimensional, have been developed over the last 20 years for the purpose of modeling the behavior of solid propellant gun propulsion systems. These codes have proven useful for explaining charge malfunctions and for studying possible remedies. Over the years, these codes have become increasingly elaborate as more complex designs have been addressed and also as the depth of simulation has increased. However, ... |
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| DYNLET1: Dynamic Implicit Numerical Model of One-Dimensional Tidal Flow through Inlets |
SEP 91 |
133 pages |
| Authors:
Michael Amein; Nicholas C. Kraus; COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS
|
| The development and verification of a simple model of inlet hydrodynamics for use in reconnaissance level quantitative studies of inlets are presented. The model, named DYNLET1 for its one dimensional modeling of the dynamic (time dependent) behavior of tidal flow at inlets, is based on the full one-dimensional shallow water equations employing an implicit finite difference technique. The model is intended for personal computer users having little or no experience ... |
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| Volume 1. Performance Flight Testing. Chapter 6. Supersonic Aerodynamics |
JAN 91 |
94 pages |
| Authors:
AIR FORCE TEST PILOT SCHOOL EDWARDS AFB CA
|
| Some basic concepts of Aerodynamics and Thermodynamics have previously been covered. These related to determination of fluid flow around various shapes and the resultant forces acting upon these shapes. Fluids previously studied were assumed to be incompressible. This assumption, among others, reduced the number of variables involved and allowed relatively simple solutions to previously complex sets of equations. Making assumptions to eliminate some variables is an everyday activity of the ... |
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| Volume 1. Performance Flight Testing. Annex 6B. NACA 1135. Equations, Tables, and Charts for Compressible Flow for Supersonic Aerodynamics |
JAN 91 |
73 pages |
| Authors:
AIR FORCE TEST PILOT SCHOOL EDWARDS AFB CA
|
| This report, which is a revision and extension of NACA TN 1428, presents a compilation of equations, tables, and charts useful in the analysis of high-speed flow of a compressible fluid. The equations provide relations for continuous one-dimensional flow, normal and oblique shock waves, and Prandtl- Meyer expansions for both perfect and imperfect gases. The tables present useful dimensionless ratios for continuous one-dimensional flow and for normal shock waves as ... |
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| One-Dimensional Analysis of a Radial Source Flow of Water Particles into a Vacuum |
31 AUG 90 |
45 pages |
| Authors:
A. Setayesh; RADEX INC BEDFORD MA
|
| An analytical investigation is made of a one-dimensional radial source flow of water into a vacuum. The equations that describe this model are a sixth-order, nonlinear, two-point boundary value problem. The problem is solved by the shooting/splitting technique. The results of this investigation are compared with the other works in the literature and the comparisons generally are in good agreement. Engineering parameters for the release of water into space are ... |
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| Magnetohydrodynamic Liquid-Metal Flows in a Rectangular Channel with an Axial Magnetic Field, a Moving Conducting Wall and Free Surfaces |
NOV 89 |
79 pages |
| Authors:
Gita Talmage; John S. Walker; Samuel H. Brown; Neal A. Sondergaard; Patricia E. Burt; DAVID TAYLOR RESEARCH CENTER BETHESDA MD
|
| Fully developed, viscous liquid-metal velocity profiles and induced magnetic field contours were studied for Hartmann number of M=2 and 10 and for different load currents for a particular rectangular channel configuration (two- dimensional Couette flow). The rectangular channel was assumed to have a homogeneous external (axial) magnetic field parallel to the moving, perfectly conducting top wall and the stationary, perfectly conducting bottom wall. The two stationary side walls were also ... |
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| Global Existence and Asymptotic Stability for a Nonlinear Integrodifferential Equation Modeling Heat Flow |
JUN 89 |
55 pages |
| Authors:
Deborah Brandon; WISCONSIN UNIV-MADISON CENTER FOR MATHEMATICAL SCIENCES
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| We study initial-value problems that arise from models for one- dimensional heat flow (with finite wave speeds) in materials with memory. Under assumptions that ensure compatibility of our constitutive relations with the second law of thermodynamics, the resulting integrodifferential equation is hyperbolic near equilibrium. We establish the existence of unique, global (in time) defined, classical solutions to the problems under consideration, provided the data are smooth and sufficiently close to ... |
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| The 17-Meter Flume at the Coastal Research Laboratory. Part 2. Flow Characteristics |
MAY 89 |
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| Authors:
John H. Trowbridge; W. R. Geyer; Cheryl A. Butman; Robert J. Chapman; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA COASTAL RESEARCH CENTER
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| This report summarizes the characteristics of the idealized one- dimensional turbulent channel flow for which the 17-Meter Flume was designed, and describes a measurement program designed to determine whether the flume can in fact produce such a flow. The measured quantities include mean velocities, Reynolds stresses, turbulence intensities and velocity spectra. Measured profiles on mean velocity, Reynolds stress and turbulence intensities are consistent with previous theoretical and empirical results. Measured ... |
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| A Method for Calculating Asymmetric Flow Through Nozzles |
JAN 89 |
24 pages |
| Authors:
Rudolf X. Meyer; AEROSPACE CORP EL SEGUNDO CA ENGINEERING GROUP
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| The asymmetric steady-state, inviscous, adiabatic flow of a perfect gas through a subsonic/supersonic nozzle is considered. The nozzle itself is either of rectangular cross section or is axisymmetric. A first-order small asymmetry induced by an entrance flow which is oblique to the nozzle axis and has a transverse pressure gradient is allowed. The cross section of the nozzle is assumed to vary only slowly as a function of the axial ... |
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| Compression and Shear Wave Propagation in Explosives |
JAN 89 |
84 pages |
| Authors:
M. Cowperthwaite; SRI INTERNATIONAL MENLO PARK CA
|
| The objective of the experimental study was to investigate the occurrence of shear-induced reaction (SIR) in an explosive subjected to the type of one-dimensional compression and shear (1DCS) loading produced by the parallel-inclined impact (PII) technique pioneered by Gupta. The objective of the theoretical study was to formulate a treatment of the reactive flow produced in an explosive subjected to 1DCS loading and thereby provide a framework for interpreting the ... |
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| Transverse CO2 Laser Two-Dimensional Gain Distributions |
24 JUN 88 |
22 pages |
| Authors:
Liyin Chen; Zexiang Chu; Haitao Chen; FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
|
| Using one-dimensional gas flows and quasi-two-dimensional electrical discharge models, we calculated the two-dimensional gain curve contour lines for equal values on perpendicular electrode planes. We studied the electrical discharge area gas flow speeds and electrical discharge parameters as well as gas constituents and similar items and their effects on the rules or patterns of changes along the direction of the gas flow. As far as each gas pressure is concerned, ... |
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| Physical Fluid Mechanics in MPD Thrusters |
18 SEP 87 |
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| Authors:
Manuel Martinez-Sanchez; MASSACHUSETTS INST OF TECH CAMBRIDGE SPACE SYSTEMS LAB
|
| This report describes work done on three areas of MPD research: (a) A rigorous theoretical examination of the one dimensional flow of a self-field accelerated plasma, clarifying the roles of area change, sonic vs. magnetoacoustic chocking, and finite magnetic Reynolds number. (b) Continued development of computational codes for axisymmetric MPD flows, and (c) Results of a first test series on two channels designed to verify productions on the effects of ... |
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| Application of a Flux Vector Splitting Methodology towards the Solution of Unsteady Transonic Flows, with Future Emphasis on the Blade Flutter Problem |
JUL 87 |
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| Authors:
Torsten H. Fransson; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This study presents a method, based on the flux vector splitting approach, to the problem of unsteady two dimensional inviscid transonic flows, with emphasis on the numerical determination of the shock position, through nozzles with varying back pressure. The method, governed by Euler equations, is first explained for one and two dimensional steady state applications, and the accuracy of the results is validated by comparison with exact (one dimension and ... |
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| Experimental and Theoretical Study on Cavitation Inception and Bubbly Flow Dynamics. Part 1. Design, Development and Operation of a Cavitation Susceptibility Meter. Part 2. Linearized Dynamics of Bubbly and Cavitating Flows with Bubble Dynamics Effects |
MAY 87 |
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| Authors:
Luca D'Agostino; CALIFORNIA INST OF TECH PASADENA DIV OF ENGINEERING AND APPLIED SCIENCE
|
| This theses presents the design, development and operations of a Cavitation Susceptibility Meter based on the use of a venturi tube for the measurement of the content of active cavitation nuclei in water samples. The pressure at the venturi throat is determined from the upstream pressure and the local flow velocity without corrections for viscous effects because the flow possesses a laminar potential core in all operational conditions. The detection ... |
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| Journal of Chinese Society of Astronautics (Selected Articles) |
06 APR 87 |
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| Authors:
Xianqi Chang; Weng-An Xu; Shi-Xue Yang; FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
|
| In this paper, a numerical solution of basic equation for one dimensional two-phase nonequilibrium flow in a combustion chamber of solid propellant rocket motors is discussed in detail, the effect of particle size on flow field in combustion chamber and pressure-time curves is analyzed, and some useful conclusions are obtained in comparison with results of one dimensional two-phase constant lag flow in combustion chamber. It is useful for predicting pressure-time ... |
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| Further Development of a One-Dimensional Unsteady Euler Code for Wave Rotor Applications |
MAR 87 |
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| Authors:
David T. Johnston; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The wave rotor consists of simple tube-like passages along and around the periphery of a drum which rotates between end walls containing inlet and outlet (partial admission) gas ports. Compression and expansion processes occur in a cyclically periodic unsteady process within the rotor such that a high pressure driver gas is used to compress a low pressure driven gas. The compressed driven gas is led from the outlet port to ... |
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| A Method for Calculating Turbulent Boundary Layers and Losses in the Flow Channels of Turbomachines |
87 |
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| Authors:
Lawrence F. Schumann; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| An interactive inviscid core flow boundary layer method is presented for the calculation of turbomachine channel flows. For this method, a one- dimensional inviscid core flow is assumed. The end wall and blade surface boundary layers are calculated using an integral entrainment method. The boundary layers are assumed to be collateral and thus are two-dimensional. The boundary layer equations are written in a streamline coordinate system. The streamwise velocity profiles ... |
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| Subdivision Froude Number |
OCT 85 |
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| Authors:
D. H. Schoellhamer; J. C. Peters; B. E. Larock; HYDROLOGIC ENGINEERING CENTER DAVIS CA
|
| A Froude number that is applicable to subdivisions of a cross section is developed assuming one-dimensional flow. The subdivision Froude number is shown to be an accurate index of the flow regime in subdivisions of a cross section. An imaginary Froude number in a flood plain indicates that the velocity is increasing with depth and that a one-dimensional flow assumption may be invalid. Mixed flow regimes at a cross section ... |
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| Weak Shock Waves Propagating in Fluid-Gas Mixtures |
FEB 85 |
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| Authors:
E. H. VAN Leeuwen; MATERIALS RESEARCH LABS ASCOT VALE (AUSTRALIA)
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| The structure of a weak normal shock wave is investigated analytically for the one-dimensional flow of a fluid, containing gas bubbles. The relative motion of the gas bubbles follow a Stokes-drag law. It is shown that for large values of time the gas bubbles behave isothermally and the shock wave approaches a steady state. For small values of time the gas bubbles behave isentropically and move faster than the fluid. ... |
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| A Computational Blast Valve Study |
FEB 85 |
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| Authors:
D. M. Hisley; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| The BRL Q1D code was modified to include a diaphragm blast valve model. The diaphragm/blast valve model was verified and used to computationally determine the suitability of using a fast-acting (blast) valve to replace diaphragm-breaking as the means of initiation flow in a large shock. For a 1- dimensional model of the Centre d'Etudes de Gramat shock tube, it was determined that a blast valve which opens in less than ... |
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| Determination of Heat Transfer Coefficient in a Gun Barrel from Experimental Data |
JAN 85 |
83 pages |
| Authors:
W. F. Donovan; ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD
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| A review of the Schmidt technique for analyzing unsteady heat flow under the restrictions of idealized boundary conditions is presented. Algebraic formulations are used for estimating wall temperatures in a ballistics environment. The procedure is given in desk-top computer program for maximum utility. |
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| Conservation Equations for a Nonsteady Flow of a Compressible Viscous Single-Phase Fluid in Various Coordinate Systems |
31 DEC 84 |
44 pages |
| Authors:
Gordon C. Yeh; Allen L. Kuhl; R AND D ASSOCIATES MARINA DEL REY CA
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| Based on a generalization of the Reynolds transport theorem the mass, momentum and energy conservation equations for a nonsteady flow of a compressible viscous single-phase fluid (expressed in vector and dyadic notations) are first formulated in integral form (in terms of moving volume and surface elements), next converted into differential form and then transformed in terms of orthogonal curvilinear coordinates. Specialized equations are obtained for three dimensional flows in Cartesian, ... |
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ONE DIMENSIONAL FLOW
