
Accession Number : AD0710839
Title : BILDUNG SCHWACHER STATIONAERER STOBWELLEN IN RELAXIERENDEN GASGEMISCHEN (Formation of Weak, Stationary Shockwaves in a Mixture of Relaxing Gases),
Corporate Author : DEUTSCHE FORSCHUNGS UND VERSUCHSANSTALT FUER LUFT UND RAUMFAHRT E V AACHEN (WEST GERMANY)
Personal Author(s) : Romberg,Guenter
Report Date : 07 NOV 1969
Pagination or Media Count : 13
Abstract : The formation of a fully dispersed shock wave in a binary mixture of relaxing gases is investigated. It is assumed that the gas is bounded by a piston at the left, and at time t = 0 is in static thermodynamic equilibrium. The piston velocity changes from zero at t = 0 to a constant nonzero value at t > 0. A uniformly valid approximation for the resulting wave motion is found by the method of matched asymptotic expansions. It turns out that the formation of a steady shock wave depends on the temperature dependence of the vibrational specific heats. If the coefficient omega of the nonlinear term in Burgers equation is greater than zero, a steady shock wave is formed. However, for omega or = 0 this is not the case. One finds that the cases omega or = 0 are not realized in nature. Numerical results for the shock formation in relaxing air indicate, how the accuracy of acoustic theory decreases due to nonlinear effects as time proceeds. (Author)
Descriptors : (*SHOCK WAVES, PRODUCTION), RELAXATION TIME, GAS FLOW, PISTONS, THERMODYNAMICS, NUMERICAL ANALYSIS, WEST GERMANY
Subject Categories : Aerodynamics
Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE