Accession Number : AD0648233

Title :   UNSTEADY PISTON-GENERATED FLOWS IN GASKINETICS,

Corporate Author : DOUGLAS AIRCRAFT CO INC SANTA MONICA CALIF MISSILE AND SPACE SYSTEMS DIV

Personal Author(s) : Toba,K.

Report Date : FEB 1967

Pagination or Media Count : 52

Abstract : An analysis of piston-generated motion in a rarefied gas is treated as an initial value problem or an initial and boundary value problem of the collisionless Boltzmann equation. The solution for a plane piston accelerated impulsively serves as a basis for studying arbitrary finite acceleration problems. Special attention is placed on the small amplitude sinusoidal oscillation of a plane piston since it can be regarded as the highly rarefied limit of the generation and propagation of sound in a gas where the Knudsen number based on the distance from the piston is large. The work seeks to clarify and extend previous theoretical investigations with emphasis on the role played by gas-surface interaction. The resulting propagation properties such as dispersion and attenuation rate are in qualitative agreement with experimental values and previous theoretical predictions. However, the dependence of these properties on the molecule-surface interaction is found to be much more involved than suggested by earlier investigators, consequently leading to substantial quantitative disagreement between the present results on the propagation properties and those predicted previously. (Author)

Descriptors :   (*RAREFIED GAS DYNAMICS, MOTION), STABILITY, PISTONS, PROPAGATION, BOUNDARY VALUE PROBLEMS, BOUNDARY VALUE PROBLEMS, SOUND, GAS FLOW

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE