Laser-Induced Spark Flameholding in Supercritical, Subsonic Flow

1997 ◽  
Vol 13 (6) ◽  
pp. 721-729 ◽  
Author(s):  
Lara D. Medoff ◽  
Andrew McIlroy
Keyword(s):  
Subsonic Flow

A new solution method for lifting surfaces in subsonic flow

AIAA Journal ◽  
1982 ◽  
Vol 20 (3) ◽  
pp. 348-355 ◽  
Author(s):  
T. Ueda ◽  
E. H. Dowell
Keyword(s):  
Solution Method ◽  
Subsonic Flow ◽  
Lifting Surfaces

Flutter analysis of cantilever composite plates in subsonic flow

AIAA Journal ◽  
1989 ◽  
Vol 27 (8) ◽  
pp. 1102-1109 ◽  
Author(s):  
Kuo-Juin Lin ◽  
Pong-Jeu Lu ◽  
Jiann-Quo Tarn
Keyword(s):  
Subsonic Flow ◽  
Composite Plates ◽  
Flutter Analysis

Study of Gas Flow in Micronozzles Using an Unstructured DSMC Method

2009 ◽  
Author(s):  
Ehsan Roohi ◽  
Masoud Darbandi ◽  
Vahid Mirjalili
Keyword(s):  
Boundary Layer ◽  
Knudsen Number ◽  
Gas Flow ◽  
Subsonic Flow ◽  
Flow Behavior ◽  
Boundary Layer Separation ◽  
Back Pressure ◽  
Viscous Force ◽  
Dsmc Method ◽  
Wide Range

The current research uses an unstructured direct simulation Monte Carlo (DSMC) method to numerically investigate supersonic and subsonic flow behavior in micro convergent–divergent nozzle over a wide range of rarefied regimes. The current unstructured DSMC solver has been suitably modified via using uniform distribution of particles, employing proper subcell geometry, and benefiting from an advanced molecular tracking algorithm. Using this solver, we study the effects of back pressure, gas/surface interactions (diffuse/specular reflections), and Knudsen number, on the flow field in micronozzles. We show that high viscous force manifesting in boundary layers prevents supersonic flow formation in the divergent section of nozzles as soon as the Knudsen number increases above a moderate magnitude. In order to accurately simulate subsonic flow at the nozzle outlet, it is necessary to add a buffer zone to the end of nozzle. If we apply the back pressure at the outlet, boundary layer separation is observed and a region of backward flow appears inside the boundary layer while the core region of inviscid flow experiences multiple shock-expansion waves. We also show that the wall boundary layer prevents forming shocks in the divergent part. Alternatively, Mach cores appear at the nozzle center followed by bow shocks and an expansion region.

A discussion on advanced methods of energy conversion- Magnetohydrodynamic power generation - Wave growth in m .h.d. generators

1967 ◽  
Vol 261 (1123) ◽  
pp. 461-470 ◽  
Keyword(s):  
Thermodynamic Properties ◽  
Acoustic Waves ◽  
Subsonic Flow ◽  
Flow Direction ◽  
Noble Gas ◽  
Travelling Waves ◽  
Combustion Products ◽  
Stationary Waves ◽  
Ohmic Dissipation ◽  
Steady Current

It has been shown that in an m.h.d. generator, acoustic waves can grow due to the coupling of fluctuations in electrical conductivity, Hall parameter and thermodynamic properties of the gas, with the ohmic dissipation and electromagnetic body forces. A new analysis of this phenomenon is presented in which waves travelling at an arbitrary angle to the flow direction in a plane perpendicular to the magnetic field are considered. In contrast to McCune’s (1964) treatment the thermodynamic properties are not restricted to perfect gas laws; and the condition for spatially and temporally growing waves is examined using a general dispersion relation which includes both these types of wave. We consider in detail (i) stationary waves in supersonic flow, and (ii) travelling waves in the subsonic flow found in the G.E.G.B. 200 MW thermal input generator being built at Marchwood, and a possible power station m.h.d. generator. It is found that the waves in the 200 MW rig which burns kerosene in oxygen will be damped. But in an oil-air combustion products generator for Hall parameters of order 3 or greater, it is found that stationary waves which grow rapidly may occur at Mach numbers greater than about 1-7; and in subsonic flow waves propagating antiparallel to the steady current vector may be amplified, though the growth rate is not excessive. In noble gas m.h.d. generators these waves are more unstable than in the oil, air combustion products generator.

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