Abstract: Transmission loss belongs to the anechoic performance of the muffler,acoustic software Sysnoise is used to analyze transmission loss for vehicle exhaust muffler through theoretical modeling,the lack of noise eliminating ability of the muffler in fundamental frequency and high frequency is found,muffler structure is improved through modern theory of muffler design,it was found that the improved muffler effect is obvious through simulation analysis,and at last the double-load method is used to measure transmission loss of the original muffler and a newly developed muffler,and simulation prediction values are in good agreement.

Key words: exhaust muffler of car, transmission loss, performance simulation analysis, double-load method, structure improvement