Viscous and thermal effects in acoustic radiation problems

Abstract

The thermal and viscous effects are generally neglected in acoustic radiation problems. In the present work we observe if these effects have any significance on acoustic radiation characteristics. Several researches have been materialised in this respect, notably, Bruneau, Beltman et al. These models study factors like inertial and viscous terms for example and then keep some while neglect others based on their significance. Our approach is quite general and we take all the factors into consideration. Our model not only deals with the thermal and viscous effects but compressibility and all other terms are taken into consideration. A system of differential equations issuing from conservation principles is linearized. Next harmonic dependence is assumed and a linear system is obtained. This linear system generates different waves among which only those are kept, which follow the sommerfeld condition. These waves produce an equal number of linear systems, and consequently; pressure, temperature, and the norm...