| Experimental Studies on the Effects of Thermal Bumps in the Flow-Field around a Flat Plate using a Hypersonic Wind Tunnel |
Jul 2012 |
109 pages |
| Authors:
Konstantinos Kontis; MANCHESTER UNIV (UNITED KINGDOM) SCHOOL OF MECHANICAL AEROSPACE AND CIVIL ENGINEERING
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 | This report presents investigations performed on the hypersonic flow-field over a flat plate with and without thermal induced bump in the University of Manchester hypersonic blowdown wind tunnel HSST at Mach no. 5.0 and free-stream Reynolds no. 6.2x106 to 11.6x106 per metre. Experiments were conducted with air as the test gas. The report consists of two parts: The first part deals with the experiments using a microheater coil of 16mm ... |
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| Boundary Layer Measurements in the Trisonic Gas-dynamics Facility Using Particle Image Velocimetery with CO2 Seeding |
22 Mar 2012 |
109 pages |
| Authors:
Daniel B Wolfe; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| Particle image velocimetry (PIV) is utilized with solid carbon dioxide (CO2) seeding material to conduct boundary layer measurements in the test section of the Air Force Research Laboratory?s Trisonic Gas-dynamics Facility (TGF), which has a 24 inch by 24 inch cross-section. Freestream velocity was set at Mach 0.3, Mach 0.5, or Mach 0.8 while stagnation pressure ranged from 500 to 2400 pounds per square foot (psf). High pressure liquid CO2 ... |
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| Fluidically Augmented Nozzles for Pulse Detonation Engine Applications |
Dec 2011 |
147 pages |
| Authors:
Larry R Smith; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Pulse Detonation Engines (PDE) operate in a cyclic manner resulting in large changes in the combustion chamber pressure. The widely varying pressure ratio between the chamber and nozzle exit makes it difficult to efficiently produce thrust since a fixed area ratio exhaust nozzle would operate off design nearly the entire cycle. Therefore, a nozzle with the capability to create the necessary area ratio throughout the cycle is required to produce ... |
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| High Order Well-balanced WENO Scheme for the Gas Dynamics Equations under Gravitational Fields |
12 Nov 2011 |
27 pages |
| Authors:
Yulong Xing; Chi-Wang Shu; BROWN UNIV PROVIDENCE RI DIV OF APPLIED MATHEMATICS
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| The gas dynamics equations, coupled with a static gravitational field, admit the hydrostatic balance where the flux produced by the pressure is exactly canceled by the gravitational source term. Many astrophysical problems involve the hydrodynamical evolution in a gravitational field, therefore it is essential to correctly capture the effect of gravitational force in the simulations. Improper treatment of the gravitational force can lead to a solution which either oscillates around ... |
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| Numerical Simulations of Pressure Spikes within a Cylindrical Launch Tube due to a Bursting Helium Flask |
09 Nov 2011 |
16 pages |
| Authors:
Harold D Ladouceur; Benjamin Gould; NAVAL RESEARCH LAB WASHINGTON DC CHEMICAL DYNAMICS AND DIAGNOSTICS BRANCH
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| A numerical model to simulate the bursting of a high-pressure flask of helium gas located within a cylindrical launch tube is described. The model provides an upper estimate for the launch tube wall pressures by assuming that the helium flask failure can be treated as a bursting balloon. The gas dynamic equations for the expansion of the 5000 psig helium region are solved utilizing the finite element program FlexPDE to ... |
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| A Minimum Entropy Principle of High Order Schemes for Gas Dynamics Equations |
18 Jul 2011 |
21 pages |
| Authors:
Xiangxiong Zhang; Chi-Wang Shu; BROWN UNIV PROVIDENCE RI DIV OF APPLIED MATHEMATICS
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| The entropy solutions of the compressible Euler equations satisfy a minimum principle for the specific entropy [10]. First order schemes such as Godunov-type and Lax-Friedrichs schemes and the second order kinetic schemes [6] also satisfy a discrete minimum entropy principle. In this paper, we show an extension of the positivity-preserving high order schemes for the compressible Euler equations in [13, 14], to enforce the minimum entropy principle for high order ... |
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| Positivity-preserving High Order Finite Difference WENO Schemes for Compressible Euler Equations |
15 Jul 2011 |
27 pages |
| Authors:
Xiangxiong Zhang; Chi-Wang Shu; BROWN UNIV PROVIDENCE RI DIV OF APPLIED MATHEMATICS
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| In [20, 21, 23], we constructed uniformly high order accurate discontinuous Galerkin (DG) and finite volume schemes which preserve positivity of density and pressure for the Euler equations of compressible gas dynamics. In this paper, we present an extension of this framework to construct positivity-preserving high order essentially non-oscillatory (ENO) and weighted essentially non-oscillatory (WENO) finite difference schemes for compressible Euler equations. General equations of state and source terms are ... |
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| Multi-Scale Modeling for Combined Shock-Shear Initiation of Energetic Solids |
07-Oct-2009 |
25 pages |
| Authors:
Keith A Gonthier; LOUISIANA STATE UNIV BATON ROUGE DEPT OF MECHANICAL ENGINEERING
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| Multi-scale interactions between initially planar deformation waves in heterogeneous energetic solids and macro-scale boundaries were computationally examined to characterize wave interaction structures and dissipative heating responsible for combustion initiation. The macro-scale response was described by a continuum theory that accounts for elastic and inelastic volumetric deformation in a thermodynamically consistent manner. The meso-scale response was described by conservation principles and an elastic-viscoplastic constitutive theory to predict contact induced nonlinear deformation ... |
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| Non-Equilibrium Gas Dynamics - From Physical Models to Hypersonic Flights (Dynamique des gaz non- equilibres - Des modeles physiques jusqu'au vol hypersonique) |
Sep 2009 |
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| Authors:
NATO RESEARCH AND TECHNOLOGY ORGANIZATION NEUILLY-SUR-SEINE (FRANCE)
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 | In-depth knowledge of gas dynamics at hypersonic speeds is required to define the environment and requirements for the design and safe operation of space vehicles, planetary probes, and rockets. Development of physical models and numerical methods has enabled major advancements in our approach to the design of vehicles, and has minimized the needs for extensive flight tests. However, there remain many challenges in our ability to model the hypersonic regime. ... |
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| Electron-Impact Excitation and Ionization in Air |
Sep 2009 |
23 pages |
| Authors:
Winifred M Huo; HUO CONSULTING LLC LOS ALTOS CA
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| In a partially ionized hypersonic flow field, electron collision plays a significant role in energy re-distribution and in the production of excited states of atoms and molecules that can subsequently radiate. Thus electron collision data is part of the database used in modelling high speed entry flows. First principles computational methods for the calculation of electron-impact data are reviewed. Their merits are discussed, based on the requirements of reliability and ... |
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| Radiation Modeling in Shock-Tubes and Entry Flows |
Sep 2009 |
104 pages |
| Authors:
Sergey T Surzhikov; RUSSIAN ACADEMY OF SCIENCES MOSCOW (RUSSIA) INST FOR PROBLEMS IN MECHANICS
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| In the present lecture some basic problems of state and solving of radiation heat transfer equation as applied to radiation modelling in shock-tubes and entry flow are discussed. The lecture contains five parts. In the first part the radiation heat transfer equation and the general definitions of the radiation heat transfer theory are presented. The definitions introduced in the first part are widely used in other parts. The second part ... |
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| Study of Factors Determining the Gain Characteristics of DOIL Active Medium |
17-Apr-2009 |
56 pages |
| Authors:
Andrey A Ionin; Andrey Y Kozlov; Nina A Ionina; Nikolay P Vagin; Leonid V Seleznev; Dmitriy V Sinitsyn; Yuriy M Klimachev; Andrey A Kotkov; Igor V Kochetov; Nikolay N Yuryshev; Anatoliy P Napartovich; Oleg A Rulev; RUSSIAN ACADEMY OF SCIENCES MOSCOW LEBEDEV INST
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| The aim of the Project is to study experimentally and theoretically the possibility of working pressure increase and increase of singlet delta oxygen (SDO) yield in conditions of gas flow through the discharge region. Also, the properties of SDO and iodine containing gas mixture will be studied during the Project. In this connection, creation of experimental discharge facilities with gas flow is needed for efficient SDO production. During the work ... |
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| High-Order Non-Reflecting Boundary Conditions for the Linearized Euler Equations |
01-Sep-2008 |
202 pages |
| Authors:
John R Dea; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| We wish to solve fluid flow problems in only a portion of a large or infinite domain. By restricting our area of interest, we effectively create a boundary where none exists physically dividing our computational domain from the rest of the physical domain. The challenge we must overcome, then, is defining this boundary in such a way that it behaves computationally as if there were no physical boundary. Such a ... |
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| Physiological and Biochemical Neuroprotection in Cetaceans: Are Some Marine Mammal Species Safeguarded from Emboli Formation and Barotrauma? |
Jan-2008 |
7 pages |
| Authors:
Terrie M Williams; CALIFORNIA UNIV SANTA CRUZ LONG MARINE LAB
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| The primary goal of this study is to evaluate the susceptibility of critical tissues in cetaceans to acoustically mediated trauma from emboli formation. By investigating tissue and whole animal mechanisms we intend to identify possible physiological/environmental factors that would allow for lipid/gas mobilization and concomitant tissue damage at depth. If successful, the results of this project will enable the development of environmentally sensitive schedules for oceanic acoustic activities by identifying ... |
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| Fundamental Physics and Practical Applications of Electromagnetic Local Flow Control in High Speed Flows |
16 FEB 2007 |
15 pages |
| Authors:
Doyle Knight; Hong Yan; Greg Elliott; Nick Glumac; Graham Candler; Alexander Zheltovodov; RUTGERS - THE STATE UNIV PISCATAWAY NJ DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
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| Achievement of the future US Air Force mission requires development of new high speed air vehicles. The aerodynamic performance of high speed air vehicles is sensitive to local flow phenomena which may adversely affect vehicle operation and possibly result in vehicle loss. An example is the Edney W shock-shock interaction which causes intense local surface heat transfer. New concepts in local flow control for high speed flows are needed to ... |
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| Quantum Algorithms for Computational Physics: Volume 3 of Lattice Gas Dynamics |
03 JAN 2007 |
315 pages |
| Authors:
Jeffrey Yepez; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
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| This report is divided into two tracks, an introductory track and a technical track. The introductory track includes a general introduction and background, introductions to two types of analog (and parallel) quantum computing, and an overview oriented conclusion. The technical track includes sections on quantum memory, conservative quantum logic, and quantum algorithm types, including quantum algorithms for the Dirac and Schroedinger quantum mechanical wave equations, the mesoscopic scale quantum Boltzmann ... |
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| Smoothed Particle Hydrodynamics: Applications Within DSTO |
OCT 2006 |
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| Authors:
D. A. Jones; D. Belton; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) PLATFORM SCIENCES LAB
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| Smoothed Particle Hydrodynamics (SPH) is a computational technique for the numerical simulation of the equations of fluid dynamics without the use of an underlying numerical mesh. Although originally developed for use in astrophysical gas dynamics, SPH has recently been applied to many other areas of numerical fluid dynamics and materials modelling, several of which have particular relevance to defense problems of interest to the DSTO. In this report we review ... |
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| Experimental and Numerical Study of Spacecraft Contamination Problems Associated With Gas and Gas-Droplet Thruster Plume Flows |
17 APR 2006 |
219 pages |
| Authors:
Mikhail S. Ivanov; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSK INST OF THEORETICAL AND APPLIED MECHANICS
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| The project consists of two large parts. The first part is the study of plume flows escaping into vacuum, and the second part deals with gasdroplet flows. These two parts are united by a common area of research, namely, contamination problems of space station surfaces due to thruster firing. The objective of the first part is accurate prediction of force and heat loads and contamination due to interaction of thruster ... |
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| Experimental Studies on Hypersonic Stagnation Point Chemical Environment |
FEB 2006 |
33 pages |
| Authors:
O. Chazot; VON KARMAN INST FOR FLUID DYNAMICS RHODE-SAINT-GENESE (BELGIUM)
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| Development of space transportation is a very challenging task. Hypersonic flight should be investigated in details to allow designing spacecraft according to the severe environment of their flight conditions. Typically during planetary re-entry, a strong bow shock takes place ahead of the vehicle detached from its nose. Across the shock a large amount of kinetic energy is converted into thermal energy. It results into a plasma flow which impinges on ... |
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| Equipment for Flow Diagnostics and Control |
31 AUG 2005 |
24 pages |
| Authors:
Mo Samimy; OHIO STATE UNIV COLUMBUS GAS DYNAMICS AND TURBULENCE LAB
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| The DURIP grant enabled us to acquire a complete and powerful stereo Particle Imaging Velocity (PIV) system, equipment for experimentally implementing real-time feedback flow control, and all the necessary equipment for automatic control of the flow facilities at the Gas Dynamics and Turbulence Laboratory (GDTL). All of these equipment items enabled us to get detailed Ply measurements simultaneously with pressure measurements. We then used the techniques described in the rest ... |
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| Hybrid Molecular Dynamics-Monte Carlo Simulations for the Properties of a Dense and Dilute Hard-Sphere Gas in a Microchannel |
13 JUL 2005 |
8 pages |
| Authors:
S. V. Nedea; A. J. Frijns; A. A. van Steenhoven; A. J. Markvoort; P. A. Hilbers; EINDHOVEN UNIV OF TECH (NETHERLANDS) DEPT OF MECHANICAL ENGINEERING
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| We present a hybrid method to study the properties of hard-sphere gas molecules confined between two hard walls of a microchannel. The coupling between Molecular Dynamics(MD) and Monte Carlo(MC) simulations is introduced in order to combine the advantages of the MD and MC simulations, by performing MD near the boundaries for the accuracy of the interactions with the wall, and MC in the bulk because of the low computational cost. ... |
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| Three-Dimensional Rayleigh-Benard Convection of a Rarefied Gas: DSMC and Navier-Stokes Calculations |
13 JUL 2005 |
7 pages |
| Authors:
S. K. Stefanov; V. M. Roussinov; C. Cercignani; BULGARIAN ACADEMY OF SCIENCES SOFIA INST OF MECHANICS
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| The three-dimensional Rayleigh-Benard convection of a rarefied gas is studied numerically by using DSMC and Navier-Stokes finite difference methods. We present the results obtained in a three-dimensional box with an aspect ratio A=Lx:Ly:Lz at a fixed wall temperature ratio r=Tc/Th=0.1. In general, the three-dimensional results confirm the validity of the zone of convection obtained in the previous author's two-dimensional considerations. A detailed analysis has been performed for Knudsen number Kn=0.02 ... |
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| Plane Couette Flow Computations by TRMC and MFS Methods |
13 JUL 2005 |
7 pages |
| Authors:
G. Russo; L. Pareschi; S. Trazzi; A. A. Shevyrin; Ye. A. Bondar; M. S. Ivanov; CATANIA UNIV (ITALY)
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| A new class of schemes of the DSMC type for computing near-continuum flows has been recently suggested: the time-relaxed Monte Carlo (TRMC) methods. An important step preceding the wide use of these schemes is their validation by classical homogeneous and one-dimensional problems of gas dynamics. For this purpose, a plane Couette flow is considered in the present paper. A comparison of TRMC results with the data obtained by time-proved schemes ... |
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| Direct-Connect Performance Evaluation of a Valveless Pulse Detonation Engine |
DEC 2004 |
79 pages |
| Authors:
Nicole K. Wittmers; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Operational characteristics of a valveless pulse detonation engine system were characterized by experimental measurements of thrust, fuel flow, and internal gas dynamics. The multi-cycle detonation experiments were performed on an axis-symmetric engine geometry operating on an ethylene/air mixture. The detonation diffraction process from a small initiator combustor to a larger diameter main combustor in a continuous airflow configuration was evaluated during multi-cycle operation of a pulse detonation engine and was ... |
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| High Altitude Chemical Injections: Non-Thermal Chemical Dynamics and Flow Field Modeling |
NOV 2004 |
16 pages |
| Authors:
Lawrence Bernstein; Matthew Braunstein; SPECTRAL SCIENCES INC BURLINGTON MA
|
| Near UV OH(A->X) and NH(A->X) emission bands at ^3100 and 3360 A, respectively, have been observed in Space Shuttle engine exhaust using the GLO imager spectrograph located in the payload bay. Spectra were collected at a resolution of 4 A for daytime solar illumination conditions during low-Earth orbit (LEO) maneuvers. While it is now understood that the OH(A-X) emissions stem from solar-induced fluorescence and photodissociation of OH and H2O in ... |
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| Microwave-Driven Air Plasma Studies for Drag Reduction and Power Extraction in Supersonic Air |
15 OCT 2004 |
123 pages |
| Authors:
Richard B. Miles; Sergey Macheret; PRINCETON UNIV NJ DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
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| Program involving modeling and experiment to explore the utility of plasmas and magnetohydrodynamics (MHD) for aerodynamic applications. Anomalous behavior of shocks on weakly ionized plasmas has been explained in terms of conventional gas dynamics with temperature gradients. Theoretical and computational models have been developed for plasma aerodynamics and nonequilibrium MHD. Models include a new theory of nonequilibrium dissociation and vibrational relaxation and kinetics of plasmas generated by electron beams 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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| Dynamics of Etching at the Gas-Surface Interface |
19 JAN 2004 |
16 pages |
| Authors:
Timothy K. Minton; MONTANA STATE UNIV BOZEMAN
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| The primary objective of this research project is to elucidate fundamental chemical and physical processes that contribute to the etching of polymers and semiconductors in dry etching environments. This fundamental knowledge should help enable the design of novel etch processes for specialty applications where fine features with high aspect ratios are critical. The new knowledge generated by this project will not only suggest new etch processes, but it will add ... |
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| Magneto-Aerodynamic Hypersonics |
DEC 2003 |
7 pages |
| Authors:
F. Witzeman; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AIR VEHICLES DIRECTORATE
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| Favorable interactions of electromagnetic fields and weakly ionized air for flow control have been recognized since the late 1950s. Potential applications of flow control to hypersonic flight vehicles were recently demonstrated by Russian research and concepts. The scientific knowledge base of this interdisciplinary area (i.e., fluid dynamics, electromagnetics, and chemical and thermal nonequilibrium gas dynamics) is extremely sparse. Therefore, controversy and even misunderstandings are abundant in the research community. This ... |
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| Enhancement of Efficiency of Operation of High-Speed Aircraft Engine Elements by Means of Separation Flow Controlling |
20 OCT 2003 |
3 pages |
| Authors:
N. V. Guryleva; M. A. Ivankin; O. M. Kolesnikov; G. N. Lavrukhin; D. V. Merekin; TSAGI (CENTRAL AEROHYDRODYNAMIC INST) ZHUKOVSKY (RUSSIA)
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| Results of investigations of the mechanism of appearance and destruction of separation zones in supersonic gas flows are presented. Methods for controlling separation phenomena were developed to increase the operation efficiency of ducts combustors inlets and outlets of high-speed aircrafts. The main trends of investigations were: 1) Study of deceleration flows in ducts of various shapes with pseudoshock; 2) Development of non-traditional manners of spatial implementation of combustion in supersonic ... |
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| Combined Non-Self-Maintained Discharge in Air for Generating of Chemically Active Particles |
OCT 2003 |
8 pages |
| Authors:
N. V. Ardelyan; V. L. Bychkov; O. A. Gordeev; A. I. Klimov; MOSCOW STATE UNIV (RUSSIA)
|
| Development of plasma technologies for problems of external and internal gas dynamics is impossible without the detailed studies of different discharge types both self maintained and non-self maintained improvement. These questions were discussed in many scientific forums recently. In particular, the longitudinal and transversal gas discharges in air were studied in air flows 1- 3 for their applications in applied problems of external and internal aerodynamics (ignition of flammable mixtures ... |
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| Comparison of Force Balance Calibration Techniques for the Nano-Newton Range |
31 JUL 2003 |
25 pages |
| Authors:
Nathaniel P. Selden; Andrew D. Ketsdever; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
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| With the rapid progress of micro- and nano-scale fabrication technology, devices are continually being created which produce extremely small forces. This creates a distinct need for a measurement instrument and adequate calibration techniques which can resolve forces below 1 micro N. Two calibration methods for force balance measurements in the nano-Newton range are presented. These methods are based on a free molecule, gas dynamic expansion through a thin-walled orifice and ... |
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| Modeling HF Gain Generator F-Atom Flows |
10 MAY 2003 |
31 pages |
| Authors:
Munson A. Kwok; Sherwin T. Amimoto; AEROSPACE CORP EL SEGUNDO CA SPACE SCIENCES LAB
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| Control volume analysis and one-dimensional reacting gasdynamics have been combined with a unique thermal-mechanical model of a combustor vessel to estimate production of fluorine atoms at the nozzle exit plane. Upon reaction with hydrogen, H2, these F-atoms are a key species in the efficient production of internally energetic hydrogen fluoride (HF) molecules, which is the lasant material for an HF chemical laser. Thus, a quantitative estimate of F-Atom density and ... |
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| Theoretical Development, Design and Testing of a Magnetic Fuel Cell |
DEC 2002 |
103 pages |
| Authors:
Joseph E. Brennan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| A magnetic fuel cell uses high-pressure gas to cause a time-dependant change in magnetic field to generate a voltage based upon Faraday's Induction Law. In this thesis, the use of a compressed magnetic gas passing through a magnetic field is described for generation of electrical power. The first stage of this thesis explores the fundamental physical nature of diamagnetic and paramagnetic gases. Once this stage is completed, it will become ... |
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| Monte Carlo Simulation of Radiation in Hypersonic Flows |
SEP 2002 |
12 pages |
| Authors:
Lain D. Boyd; CORNELL UNIV ITHACA NY DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
|
| Radiation is generated in hypersonic flows of missiles. Depending on the flight altitude, the gas dynamics may be modeled by continuum or kinetic simulation techniques At high altitude, kinetic methods are more physically accurate, but continuum methods are more numerically efficient. In an attempt to utilize the best of both approaches, we are undertaking the development of a hybrid continuum-kinetic method for high altitude hypersonic flows. Ultimately, such a method ... |
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| Hypersonic Pulsing Regimes of Magnetic Field Emerge From Lower Layers of the Convective Zone Up to the Photosphere of the Sun |
JUL 2002 |
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| Authors:
S. V. Alekseenko; V. A. Romanov; K. V. Romanov; I. V. Semeonov; KRASNOYARSK INST OF NON-FERROUS METALS (USSR)
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| Oscillations of an isolated thin magnetic tube at various depths of the convective zone and in the atmosphere of the Sun are investigated in the present work in the approximation of ideal magnetic gas-dynamics. These oscillations are the source of generation of acoustic waves whose transition in weak shock waves provides anomalous heating of the solar atmosphere. The modes of small-amplitude linear oscillations at various depths of the convective zone ... |
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| Gas-Surface Interaction Model Evaluation for DSMC Applications |
JUL 2002 |
10 pages |
| Authors:
Dean C. Wadsworth; Douglas B. VanGilder; Virendra K. Dogra; ENGINEERING RESEARCH AND CONSULTING INCEDWARDS AFB CA
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| The general gas surface interaction event is considered to be parameterized by the molecule's incident energy magnitude and incident angle relative to the surface normal. These parameters are used to estimate the degree of nonequilibrium that arises for typical applications, and the quality of scattering predictions made by common few-parameter models such as the Maxwell model. Experimental measurements and molecular dynamics simulations are evaluated as potential sources of data to ... |
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| Ejection in Wind Tunnels. The Theory Explaining Pressure Losses in Subsonic Diffusers |
JUL 2002 |
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| Authors:
Yu. K. Arkadov; TSAGI (CENTRAL AEROHYDRODYNAMIC INST) ZHUKOVSKY (RUSSIA)
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| When testing an aircraft model in a wind tunnel the drag of the model itself requires only a low proportion of the wind tunnel compressor power- say the blockage ratio which is a few per cent. An almost equal proportion is lost in the balance i.e. 90% of the electric power consumed is spent to recover the total pressure loss in wind tunnel diffusers. Therefore it is crucially important to ... |
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| Peculiarities of Gasdynamics of Descent and Landing on Planets with Rarefield Atmosphere |
JUL 2002 |
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| Authors:
A. A. Bachin; E. M. Kalinin; V. I. Lapygin; N. E. Khramov; CENTRAL SCIENTIFIC RESEARCH INST OF TECH AND MACHINE BUILDING MOSCOW (USSR)
|
| TSNIIMash was one of the first scientific centers were such investigations had been started dealing with force and heat loads from the engine jets acted on the space vehicle structure during soft landing on the lunar and Martian surfaces. Interaction of single/multiple jet with oncoming flow or surface is characterized by appearance of a large number of shock waves contact surfaces separated zones and other peculiarities and this defined the ... |
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| Special Features of Using N2O For Heating of The Test Gas in A Hot-Shot Wind Tunnel |
JUL 2002 |
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| Authors:
M. I. Yarozlavtsev; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSK INST OF THEORETICAL AND APPLIED MECHANICS
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| The study of heat and mass supply in gas-dynamics models with combustion involves the necessity of modeling not only aerodynamic criteria of similarity (M, Re, St, etc.) but also natural values of stagnation pressures and temperatures, since the conditions of self-ignition of the fuel, heat release in time and space, and chemical reaction rate depend significantly on P(sub 0) and T(sub 0). These or similar conditions can be obtained in ... |
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| Measurements of Transient Aerogasdynamic Forces and Moments |
JUL 2002 |
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| Authors:
V. I. Lagutin; V. I. Lapygin; CENTRAL RESEARCH INST FOR MACHINE BUILDING MOSCOW (RUSSIA)
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| The examples of realization in TSNIIMASH of measurements short duration aerogasdynamic forces and moments in piston gasdynamic units U-11 and U-7, shock tube U-I 2 and vacuum chambers U-22 and U-22M are given in the present paper. The characteristic run duration in these facilities is 0,01-0,2 5, and loading measurements are carried out without consideration of inertial forces. Some methodical approaches of measuring transient aerodynamic forces and moments acted on ... |
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| Comparison of Fuels Used for Chemical Heating of the Working Medium in Gasdynamic High-Enthalpy Facilities |
JUL 2002 |
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| Authors:
V. V. Shumskii; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSK INST OF THEORETICAL AND APPLIED MECHANICS
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| In the present study we compare hydrogen, acetylene, propane and their mixtures with nitrogenous oxide from the viewpoint of the amount of fuel required for reproducing full-scale enthalpy and pressures, with due regard made for their ignition conditions. |
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| Aerogasdynamics of Waveriders with Powder-Law Compression Surfaces |
JUL 2002 |
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| Authors:
I. I. Mazhul; R. D. Rakhimov; RUSSIAN ACADEMY OF SCIENCES NOVOSIBIRSK INST OF THEORETICAL AND APPLIED MECHANICS
|
| Use of the well-known flows streamlines with specified properties to design spatial lifting configurations (waveriders) allows to simplify essentially an analysis of such form characteristics in the so-called design flow regimes which corresponds to their construction conditions. Waveriders using as the basis of a future hypersonic aircraft is widely discussed. Waveriders characteristics in the design regimes have been analyzed in a number of works. However, the off-design regimes applying to ... |
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| Investigations of Novel Energetic Materials to Stabilize Rocket Motors |
30 APR 2002 |
276 pages |
| Authors:
Merrill W. Beckstead; Fred E. Culick; Thomas B. Brill; Thomas A. Litzinger; Vigor Yang; Gary A. Flandro; Robert A. Frederick; M. C. Lin; E. W. Price; CALIFORNIA INST OF TECHNOLOGY PASADENA CA JET PROPULSION LAB
|
| This document is the final report of the Caltech Multidisciplinary University Research Initiative (MURI), "Investigations of Novel Energetic Materials to Stabilize Rocket Motors," ONR Contract No. N00014-95-1-1338. With a one-year no-cost extension, the program covered the period 1 October 1995 to 30 September 2001 and involved Principal Investigators at nine Universities. In addition, for three years, funds from another source supported research by seven Russian research groups. Participants in the ... |
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| Air Force Support for the Twenty-Third International Symposium on Shock Waves |
15 MAR 2002 |
3 pages |
| Authors:
Frank K. Lu; TEXAS UNIV AT ARLINGTON
|
| The Twenty-Third International Symposium on Shock Waves, hosted by the University of Texas at Arlington, was held in Fort Worth, Texas, from July 23 through July 27, 2001. The symposium covered a comprehensive range of topics involving shock waves, ranging from fundamental to applied. Plenary, oral and poster sessions were included. The symposium included a companion program and off-site events. A total of 210 delegates and 43 accompanying persons attended ... |
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| Generation and Diagnostics of Super-Ionized Air Plasmas |
OCT 2001 |
16 pages |
| Authors:
Charles H. Kruger; Christophe O. Laux; STANFORD UNIV CA DEPT OF MECHANICAL ENGINEERING
|
| This grant has permitted the acquisition of instrumentation to produce and study super-ionized air plasmas present grant allowed acquisition of the instrumentation necessary to experimentally demonstrate large power budget reductions. The instrumentation acquired with this grant comprises a repetitive pulse generator (100 kHz, 12 kv, 10 ns), a fast intensified CCD camera for optical diagnostics of the pulsed discharge, a fast sampling oscilloscope for electrical diagnostics of the discharge, and ... |
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| 18TH International Colloquium on the Dynamics of Explosions and Reactive Systems |
AUG 2001 |
158 pages |
| Authors:
J. R. Bowen; UNIV OF WASHINGTON SEATTLE
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| The 18tb International Colloquium on the Dynamics of Explosions and Reactive Systems was held at the University of Washington from 29 July through 3 August 2001. Two hundred and twenty nine participants from 21 countries gathered to discuss the latest advances in experimental investigation and mathematical modeling of explosions and reactive systems. Two minisymposia focused on pulsed detonation engines and ram accelerators, while 186 podium presentations and 40 posters covered ... |
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| Basic and Applied Studies of the Ram Accelerator as a High Performance Launcher |
28 JUN 2001 |
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| Authors:
Carl Knowlen; Adam P. Bruckner; UNIV OF WASHINGTON SEATTLE AEROSPACE AND ENERGETICS RESEARCH PROGRAM
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| The ram accelerator is a hypervelocity launch concept that uses a confined, in-tube ramjet propulsive cycle to generate thrust for the acceleration of a projectile. Key technical issues involving the starting and operation of the ram accelerator were investigated at fill pressures up to 200 atmospheres. The research was initiated to evaluate the feasibility of using a ram accelerator of limited length for specific applications, e.g., mobile or ship-based. In ... |
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| Theory of the Lattice Boltzmann Method: Lattice Boltzmann Models for Non-ideal Gases |
APR 2001 |
28 pages |
| Authors:
Luo Li-Shi; INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA
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| In this paper a procedure for systematic a priori derivation of the lattice Boltzmann models for non-ideal gases from the Enskog equation (the modified Boltzmann equation for dense gases) is presented. This treatment provides a unified theory of lattice Boltzmann models for non-ideal gases. The lattice Boltzmann equation is systematically obtained by discretizing the Enskog equation in phase space and time. The lattice Boltzmann model derived in this paper is ... |
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| Tensile Strengths of Silicon Carbide (SiC) Under Shock Loading |
MAR 2001 |
56 pages |
| Authors:
Dattatraya P. Dandekar; Peter T. Bartkowski; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
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| The present work was initiated to measure and compare tensile strengths (i.e., spall thresholds) of five different types/varieties of silicon carbide materials. Two of these materials were sintered, and the remaining three were hot-pressed. Three types of silicon carbides (one sintered by Sohio and. the other two hot-pressed by Cercom) were manufactured in the United States. The remaining two varieties of silicon carbides were manufactured in France. Spall strengths of ... |
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Reports by Keyword(s)
GAS DYNAMICS
