Accession Number : AD0693334

Title :   NON-LINEAR NON EQUILIBRIUM FLOWS.

Descriptive Note : Annual scientific rept. no. 1, 15 Nov 67-14 Nov 68,

Corporate Author : NAPLES UNIV (ITALY) ISTITUTO DI AERODINAMICA

Personal Author(s) : Napolitano,L. G.

Report Date : JUN 1969

Pagination or Media Count : 74

Abstract : The first part of the report deals with the non-linear acoustics for singly reacting media. The non-linear wave equation is derived to within a small perturbation approximation and its physical implications are discussed. The type and nature of additional simplifications which can be obtained under particular hypothesis on the equilibrium thermodynamic properties of the medium and/or the kinetics of the process are analized and relevant analogies are established and commented upon. In the second part the effects of the multiplicity of principal relaxation frequencies are considered. By means of the spectral decomposition of the relaxation matrix the following result is proved: the features of any linearized non-equilibrium flow field do not depend on the number of independent rate processes taking place in the gas mixture but, rather, on the number of distinct principal relaxation frequencies. The analogies following as a corollary of this statement are pointed out and discussed. (Author)

Descriptors :   (*NONEQUILIBRIUM FLOW, NONLINEAR SYSTEMS), ACOUSTIC PROPERTIES, THERMODYNAMICS, RELAXATION TIME, FREQUENCY, PROPAGATION, ITALY

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE