Research On Acoustic Characteristics Of A Vehicle Exhaust Muffler Based On Coupling Thermal Acoustic And Solid

Exhaust noise,as the main noise source of automobile,has a serious impact on the structural and acoustic performance of muffler due to its emission of high-temperature waste gas.At the same time,there is an interaction between structure and sound field.Therefore,it is very important to study the performance of muffler under the condition of multi-field coupling of thermo-acoustic solid.This paper studies the influence law of muffler on the performance of the muffler under the condition of thermal acoustic and solid coupling.Considering the coupling condition,the structure optimization design of the muffler is carried out and the experimental verification is carried out.The work content of this paper is as follows:(1)Taking a truck muffler as the object of study,the internal temperature field and the acoustic performance before and after considering the temperature were analyzed,and the influence law was obtained,and the theoretical formula was used for analysis.(2)The structure and acoustic performance of the muffler under the condition of thermo-solid coupling,thermo-acoustic coupling and thermal acoustic solid coupling were analyzed by using finite element method.(3)Considering the thermoacoustic coupling,the acoustic properties of the simple muffler are analyzed,and the influence law of different muffler on the muffler is obtained.(4)Bench experiment of the original muffler.According to the target spectrum and the characteristics of different silencing anechoic unit to design of thermoacoustic solid coupling complex muffler.Analysis the influence of the acoustic performance of muffler in different condition of muffler structure thickness.According to the silencing effect,choose the the best optimal solution,and test of the project.The results show that the optimized silencer muffler performance improved obviously and reduce the exhaust noise effectively.Based on the previous work,the influence law of multi-field coupling on muffler performance is studied and the basic guidance for noise reduction optimization of muffler under coupling condition is provided which is important in theoretical and application value.