TURBULENTLIKE QUANTITATIVE ANALYSIS ON THE SOUND ABSORBING CHARACTERISTICS OF METAL RUBBER

Metal rubber has much penetrated pores from the surface to the core,and the quasi-periodic and irregularity features are very similar to those of turbulence. Because of the irregularity within the structure of metal rubber, even if the Reynolds number is very small, turbulence still occurs. Therefore, the concept of the Kolmogorov local isotropic turbulence is introduced and two assumptions on the local isotropic Kolmogorov turbulence are obtained. The physical model of turbulence is established, and the sound absorbing characteristics of metal rubber are quantitatively analyzed and the relationship of the expression between the energy dissipation rate of metal rubber material and its structural parameters is obtained. The results show that the introduction of turbulence statistical method provides not only a reliable theoretical basis for the optimal design of metal rubber instruments such as damper and muffler but an effective quantitative analysis method for engineering applications of ultra-light metal porous materials.