Predication of Acoustical Dissipation in Large Irregular Cavities by Helmholtz Solver

F. Mbailassem [1], Q. Leclere [1],
[1] LVA - INSA de Lyon, France
Published in 2015

This paper introduces an efficient model to describe energy dissipation in acoustic. When the propagation domain has hard wall boundary conditions only viscous and thermal losses happen and are completely described by the so-called Full Linearized Navier-Stokes model (FLNS) which is implemented in thermoacoutics interface using the COMSOL Acoustics Module. This model defined by a set of equations solving for three variables is however very costly in time and memory. In this work we present a lightweight approach based on perturbations theory using just the isentropic Helmholtz equation (Acoustic pressure interface) solution to predict acoustical damping in cavities having any dimensions greater than viscous and thermal boundary layer. Application of this theory to irregular cavities yield results in quiet agreement with those of the FLNS.