In this work, an impedance tube apparatus for high temperature sound absorbing test of porous metal is introduced. The temperatures and acoustic pressures at some key positions in impedance tube are directly measured by using several thermal couples and acoustic microphones. On the other hand, to vividly display the acoustics and temperature field, two COMSOL modulus, heat transfer in porous media and pressure acoustics in frequency domain, are applied to solve multi-physical problem involved in this study. In simulation analysis, the heat transfer between skeleton of porous material and air in pores, thermal convection of air inside or outside impedance tube and sample section, heat radiation of outer surface of heating sections of the apparatus, and the assumption of propagation of planar acoustic waves in impedance tube are considered also. Moreover, Johnson-Champoux-Allard model is applied for the numerical simulation of acoustic field in impedance tube with a porous metal filled. The experimental results show that the maximum absolute error for the simulation of temperatures at the key positions is 8K. And the result of acoustic field from COMSOL simulation is reasonable as well.
展开▼
