Analysis of self-excited thermoacoustic vibrations by using concentrated mass model

Abstract

Noise countermeasures are an important engineering problem, and acoustic analysis methods for noise prediction and reduction have been widely studied. In a thermoacoustic engine, the sound is generated when the air vibrates due to the temperature gradient inside the pipe. Applying this effect may reduce noise by using the temperature distribution. Therefore, the purpose of this study is to analysis an acoustic space with a temperature gradient using a concentrated mass model. In previous study, we built a linear model of an acoustic tube with temperature gradient and validate the proposed model by numerical calculation of heat storage device in a cylindrical pipe. In this report, we propose the analysis method of self-excited thermoacoustic vibrations using the previous model. Two types of methods using a transfer matrix and a dynamic stiffness matrix is examined as methods for analyzing self-excited vibrations. The proposed methods are validated by comparison with the numerical calculation results shown in another study.