As the compact design of a muffler system within a constrained

environment of a existing machine room becomes obligatory, it also

becomes essential to maximize the acoustic performance of mufflers

under space constraints. In this paper, the shape optimization of a

double-chamber muffler with an extended tube is presented. The

main characteristic of the solution methodology is the use of genetic

algorithm (GA) as the optimizer. In the paper, the acoustic perfor-

mance of sound transmission loss (STL) derived by transfer matrix is

conjugated with the techniques of GA searching. A numerical case-As the compact design of a muffler system within a constrained

environment of a existing machine room becomes obligatory, it also

becomes essential to maximize the acoustic performance of mufflers

under space constraints.　In this paper, the shape optimization of a

double-chamber muffler with an extended tube is presented.　The

main characteristic of the solution methodology is the use of genetic

algorithm (GA) as the optimizer.　In the paper, the acoustic perfor-

mance of sound transmission loss (STL) derived by transfer matrix is

conjugated with the techniques of GA searching.　 A numerical case