关键词：汽车；消声器；声学
摘 要：The dimention for muffler has great impact on the car engine.Based on software GAMBIT,GT-POWER,SYSNOISE,through comprehensively using finite element and boundary element method,simulating and analyzing the acoustic performance for the basic noise reduction unit,establishing the finite element model,comparing the frequency and noise reduction of different volume ratio of cavity and throat tube.Simulation analysis and experimental results show that the resonant structure parameters have a direct effect on its resonant frequency and noise reduction amount,the relationship characteristic between them is that the ratio more bigger,the requency and noise reduction amount more bigger,too.And draw the two relation formulas through calculation.