Performance Analysis And Research Strengthening Exhaust Muffler Acoustic Characteristics Based On The Frequency Band

With the improvement of consumers for cars environmental requirements, more and more is also high to the requirement of vehicle noise control, control of automotive main noise source of engine noise has become the vendor of choice. Due to the domestic enterprise technology is weak, and the muffler design level is limited, mostly by empirical trial and error method is given priority to, the method of the high cost of long cycle poor consistency. To improve the muffler design means to strengthen the computer simulation design, silencing effect prediction, guide the muffler design and experiment with theoretical significance and practical engineering value.Using engine virtual test software GT-suite, analyze noise elimination effect of anechoic units according to the frequency band. Use the results of the analysis and the orthogonal experiment method to improve the target muffler band silencing effect. The commercial vehicle exhaust system as the research object. First of all, analysis of the taper pipe structure, the structure of the perforated tube, double tube structure and various single silencing structure as different structural parameters and installation position attenuation characteristics based on frequency band. Secondly, using software GT-suite engine, establish the heavy-duty commercial vehicle engine model according to the engine physical parameters by engine compared with the simulation results, make sure the experimental results verify the model accuracy, obtaining band noise characteristics of the engine. Finally, According to the engine noise frequency distribution, the choice in engine noise band biggest silencing effect better several silencing structure into the original muffler. Use the method of orthogonal test, to select the silencing structure factors, the interaction between meter and factors of the orthogonal experiment. Choose the optimal combination of structural parameters of muffler by engine and muffler coupling simulation. According to choose the optimal parameter combination muffler simulation computation results show that the optimized 1.97 dB lower than the original muffler tail pipe noise, exhaust back pressure rise 1.9 kPa, but the loss of engine power is almost negligible.The paper applies the method of band noise analysis. For different engine main noise band, to join the band noise elimination in the muffler noise elimination structure with better effect, specific design match engine muffler, muffler for automobile enterprise development puts forward a new method, development has a guiding significance for other similar models muffler.