The Novel Design Of Exhaust Muffler For A Certain Engine

With the development of technology and time, people know more about the harm ofnoise and pay more attention on it. In recent years, the industry in our country isdeveloping increasingly and the noise from engineering becomes main resource of thecity noise. The engine noise is the important part of engineering noise. The noise ofexhaust is one of the main noise of engine. The most effective way to control the noiseof exhaust is to use the muffler. According to the spot experiment and three-dimensionalacoustic simulation, this paper analyzed the acoustic property of original muffler andapproved the improved project. The analysis for acoustic field of the approved mufflerwas carried out and the new structural parameter of the muffler was obtained meanwhile.Then we carried out the spot experiment to prove if the new design met the demands.Firstly, this paper introduced the research actuality of muffler and then relative theoryabout the design of muffler was mentioned, which supplied the further research withtheory foundation and reference.Secondly, the insert loss date of original muffler was obtained through the spotexperiment. Then this paper analyzed the frequency character of the noise after beingmuffled by muffler and distinguished the frequency of the unrestricted noise. Thethree-dimensional and finite element model of muffler was built by modeling softwareUG and mesh dividing software Hypermesh, respectively. According to the Virtual.lab,we analyzed the acoustic structure of the muffler and got the frequency character of themuffler. The simulative results were coincided with the relative experiment, whichproved partly the rationality of the three-dimensional acoustic simulation of muffler.Then, we improved the structural parameter and arrangement form of the mufflerand raised the improved project of the structural parameter based on the obtainedexperimental results and the Resistance Muffler theory. On the foundation ofnumeration of experience formula and repeated soft simulation, we got the sizeparameter of the new muffler and designed a novel resistance muffler.Finally, via the spot experiment, it proved that if the new muffler met the anticipateddemands in this paper. The obtained results indicated that the sound deadeningcapacity on various frequency of the muffler with new structure met the requirementsand the main properties of the new muffler were superior to the old one, especiallynoise elimination ability on the low frequency. What’ more, the total sound pressure ofexhaust noise reached104.9dB(A), which met the demand of design. All of the analysis, design and improving processes were benefited to the production.