Determination of the acoustical parameters of sintered porous metals

The acoustical parameters of porous materials such as tortuosity factor, viscous and thermal characteristic length, and static flow resistivity, are very important, but not obtained directly from the conventional experimental measurements. Hence, in this study, the methods based on the Johnson-Champoux-Allard model and including the simulated annealing generic algorithm and successive quadratic programming are put forward so as to determine the acoustical parameters of a kind of sintered fibrous metal. And the corresponding results are compared to each other. It is found that the determination of the acoustical parameters of the sintered fibrous metals employing the simulated annealing generic algorithm is not only accurate, but also has good robust properties. Moreover, the work shows that utilizing the successive quadratic programming method can also obtain good results provided that the optimization variables are chosen appropriately. Finally, some calculated and measured results are given and discussed to verify the validity of the presented methods further.