A Engine Exhaust Muffler Acoustic Performance Simulation And Research

The engine exhaust noise is one of the main noise sources of a vehicle，At presentthe most direct and effective way to control the noise is to equip exhaust muffler．So ithas very important significance for the muffler acoustic properties research.Traditional method for exhaust muffler designing is mainly depends onexperience, one dimensional plane wave theory and lots of experiments,and that willbe time consuming，laborious and expensive．And one dimensional plane wave theorycan’t accurately simulates three dimensional wave effected by practicalfactors,etc.And the simulation results is not accurate.Three dimensional numericalmethods of exhaust muffler performance accurate simulation of in the meantime alsocan consider to a variety of external factors influence, It is the effective method forexhaust muffler designing and improving.This paper uses finite element method andsysnoise software,ansys software to simulate muffler attenuation.This paper firstly accounts acoustic basic theory, the vehicle exhaust noise theory,muffler principle, the calculation of transmission loss,And then make exhaust noisetest of465Q engine,get exhaust noise spectrum.And then we can find the badattenuation performance frequency of primitive muffler. The paper uses Pro-e to make3D model, then import it to Ansys for grid partition, and use sysnoise to simulatemuffler acoustic properties, get the muffler’s transmission loss curve.By comparingthe test and simulation data, to verify the accuracy of the simulation model. Use thesame method to simulate the every reduction structure, get the transmission losscurve, find reduction structure defcts,To contrast the transmission loss curve betweenthe new and primitive muffler,realize the expected improvement goals.Through numerical simulation technology,we can design exhaust muffler rapidand accurately,and it will reduce the test times, improve the design efficiency. In thispaper the acoustics performance exhaust muffler3-d numerical simulation can notonly provide a powerful guidance for the test, but also improving the experienceaccumulated and the improved methods, is important reference for muffler design andimprovement.