Shape Optimization of One-Chamber Perforated Mufflers Filled with Wool Using Simulated Annealing

Abstract

Research on dissipative and reactive mufflers has been addressed. However, the acoustical performance -sound transmission loss (STL)- of mufflers within a constrained space is often insufficient. In this paper, to improve the acoustical efficiency, a one-chamber perforated muffler filled with sound absorbing wool optimized by using simulated annealing (SA) in conjunction with the numerical decoupling technique is presented. A numerical case in eliminating a broadband noise is also introduced. To verify the reliability of SA optimization, optimal noise abatements for the pure tone are exemplified. Before the SA operation can be carried out, the accuracy of the mathematical models has been checked using the experimental data. Results indicate that the maximal STL is precisely located at the desired target tone. Moreover, the STL can be improved when the ratio of the perforated tube’s length and the porosity of the perforated tube and the acoustical flowing resistance of the wool increase and the Mach number and the expansion ratio decrease. Consequently, a successful approach used for the optimal design of the one-chamber dissipative mufflers within a constrained space has been demonstrated.