Nongray thermal radiation effects on the sound wave propagation in gas-particle two-phase medium

Abstract

A theoretical analysis has been carried out to study the acoustic wave propagation through a hot planar gas-particle two-phase medium with emphasis on the nongray gas radiation effects. The relaxation model and P-1 approximation were employed to describe the momentum exchange between two phases and the radiant energy transfer, respectively. Nongray gas radiation was taken into account while the radiative contribution by suspended particles were assumed negligible. The nongray radiative property of gas was modeled using WSGGM and SGM and their results were compared and discussed based on the gray gas approximation. The results have shown that the effects of various radiation models appeared only in the radiation-induced attenuation mode. It was the biggest for the gray gas approximation whereas the smallest for the nongray model with WSGGM. The acoustic characteristics in the induced attenuation by nongray radiation models was also found to occur through nonlinear interaction by a combination of each gray band effect. (C) 2002 Elsevier Science Ltd. All rights reserved.