Design Of Muffler For Passenger Vehicle

With the development of automobile and transport business, the automobile quantity increases significantly every year and causes the city noisier and noisier. Besides, people become more and more dependent on automobiles. So they have a higher requirement that the automobiles should be more comfortable with lower noise. The manufacturers put the lower noise of cars as the main objective. One-third proportion noise of the car is exhaust noise and it's hard to reduce the whole automotive system's noise, as it involves in many sound sources and requires a certain technical research. But only control the individual noise is much easier. As the engine speed increases and the engine becomes more and more compact, which causes the exhaust noise and the automobiles'noise increasing. The exhaust noise can not be reduced only by controlling the noise source itself. The most effective and simple method is application with the exhaust silencer. A good muffler can not only reduce the exhaust noise but its power should not be lost much. Besides, different vehicles need different requirements of noise reduction. Therefore, the exhaust muffler needs further studied.Firstly, some test projects related to muffler are described, including test method and process of exhaust noise and exhaust back-pressure test in Japan and China. Then a comparison is made in difference of test standard between Japan and China. The results show that Japanese legislation fits well the actual noise status of driving vehicles and is stricter in vehicle exhaust noise limit than China.GT-Power is applied to design muffler for the turbocharged engine. By analyzing the engine speed with 1/3 octave center frequency, the overall and order noise, three different mufflers are designed. Then the muffler models and performance evaluation models are established. After that, the acoustic performances are simulated, the results can achieve project objective. The model one is the best muffler in the three models and the performance can meet the customer's requirement.The drainage and heat insulation of mufflers are designed based on this construction, considering the mufflers'structure, materials and actual installation position.