The Research Of Multi-field Coupling For Sound Absorption Of Porous Metal Materials

Based on the acoustic properties of porous metal materials under normal pressure and room temperature research, the sound absorption mechanism of porous metal material was deduced in detail under the action of the high temperature and SPL; the sound absorption mechanism of porous metal material in several physical force fields was simulated by COMSOL Multiphysics; which was provided for the reference of theoretical calculation and usage basis for the acoustic noise reduction of porous metal materials under extreme conditions.Firstly, the acoustic absorption theory of porous metal material is studied in the high temperature. To simplify the porous metal material as the cylindrical hole, thermal effect of circular tube was considered, and the expression of bulk modulus adopt to high temperature was deduced. By describing the relationship between temperature and the acoustic parameters of porous metal materials, the acoustic performance of the porous metal material under the action of different temperature field was theoretically calculated. Using COMSOL to the porous metal material in uniform temperature field, temperature gradient, the material internal with convection three scenarios for simulation, the acoustic properties of porous metal material under the action of different temperature field were obtained, and the sound absorption regularity of porous metal materials under high temperature was summarized.Secondly, this paper expounds the finite amplitude wave theory of nonlinear propagation and waveform distortion, using COMSOL on the nonlinear propagation of finite amplitude wave simulation, and the waveform and spectrum diagram of the non-linear propagation of sound wave were got. The non-linear viscous effect for the porous materials of acoustic parameters was analyzed; the efficient density was obtained after Forchheimer modified, and the acoustic performance of porous metal material under high SPL was obtained by calculating. Using COMSOL on the acoustic performance simulation of porous metal materials under the action of the non-linearity, the results were compared with test values and the curve of the alignment is good.Finally, based on the acoustic performance research of porous metal material under high temperature and non-linearity, the porous metal material internal energy dissipation theory under multiple physical fields was analyzed by using the constitutive equation of particle flow. Using COMSOL on the acoustics performance simulation of porous metal material under the action of multiple physical fields, the sound absorption regularity of porous metal materials under the action of multiple physical fields was summarized, and a feasible method of acoustic performance of porous metal materials under complex environment for the future of the theoretical calculation and simulation was provided.