On Numerical Simulation of Sound Damping Mechanisms in the Cell of a Sound-Absorbing Structure

Numerical simulation of acoustic processes with an interferometer at high acoustic pressure levels is one of the ways to noise reduction processes using samples of sound-absorbing structures (SAS). In the course of research, an SAS sample consisting of a single Helmholtz resonator of circular shape was used. Studies were conducted at sound pressure levels of 110, 130, 140, and 150 dB. Results obtained with the interferometer with normal wave incidence were taken as a basis. In the calculations, systems of linearized and complete Navier-Stokes equations were used. The results obtained with the linearized Navier-Stokes equations make it possible to determine the acoustic characteristics of the sample for linear modes of operation with sufficient accuracy. The complete system of Navier-Stokes equations, taking into account compressibility, allowed good qualitative and quantitative agreement with the experiment at high acoustic pressure levels.