Optimal Design for Multi-Diffuser Mufflers Using the Simulated Annealing Method

In this paper, a four-pole system matrix for evaluating acoustic performance (STL) is derived using a decoupled numerical method. During the optimization process, a simulated annealing (SA) method, which is a robust scheme utilized to search for the global optimum by imitating a physical annealing process, is used. Prior to dealing with a broadband noise, to recheck the SA method's reliability, the STL's maximization relative to a one-tone noise (400 Hz) is performed. To assure the accuracy of muffler's mathematical model, a theoretical analysis of one-diffuser muffler is also confirmed by an experimental data. Subsequently, the optimal results of three kinds of mufflers (muffler A: one diffuser; muffler B: two diffusers; muffler C: three diffusers) have also been compared. Results reveal that the acoustical performance of mufflers will increase when the number of diffusers installed at the muffler inlet increases.