Research On Matching Exhaust System Of Petrol Engine With Some Passenger Vehicle To Reduce Noise

According to the rapid development of automotive industry and transportation industry at domestic, the vehicle ownership quantity in our country increases a lot recently. But the caused traffic noise pollution problems, which have serious negative influence to human work and health, have became a public disaster influenced and troubled people life. Countries around the world all begin to make stricter requirements to control the vehicle noise.The exhaust noise of internal combustion engine is the major vehicle noise source. According to the improvement of internal combustion engine rpm and intensification, the problem of airflow speed increasing in exhaust system increases, which means the exhaust noise increases, and causes the increasing trend of vehicle noise, should be paid enough attention. The relatively most effective method to control the exhaust noise of internal combustion engine is to use exhaust muffler. But the installation of the exhaust muffler could increase the exhaust resistance and the exhaust back pressure, which will influence the dynamic and economy of the engine, and will be against conservation principle and sustainable development we look forward to.Thus, performance predicts and optimization designs of internal combustion engine exhaust muffler become the focus of this article. At present, vehicle noise control, especially the pass by noise, is the important research topic in vehicle industry.By using the transfer matrix method and simulation software of one-dimensional acoustic performance, GT-POWER to do the value simulation analysis of intake and exhaust system on special new vehicle with small displacement, this topic built one-dimensional joint model for intake system and exhaust muffler with engine, solved the problems such as the model building and related parameters setting of intake and exhaust system. Take the simulation calculation result as the base of making improving proposal for noise reduction by getting the parameters such as transfer loss and pressure loss of intake system, and muffler value, transfer loss, pressure loss and exhaust back pressure of exhaust muffler through value simulation. Because the vehicle structure had been confirmed, the larger changes could not be don, except structure optimization of intake and exhaust muffler to reduce vehicle noise. Check proposal rationality and validity through the value simulation and test verification, and optimize the noise performance of intake and exhaust system on the base of value simulation result and external acceleration noise test data. The better consistency between test result of external acceleration noise and value simulation means a positive engineering practical value for using simulation software of one-dimensional acoustic performance, GT-POWER to optimize vehicle exhaust system noise reduction. And it solves the problem that how to reduce noise without larger vehicle changes.Under the guide of Professor Shi Wenku, the author of this article optimized the special intake and exhaust system, reduced the noise of intake and exhaust system, and then reduced the vehicle external acceleration noise by reading lots of related documents and taking the research of optimization design for intake and exhaust system during working as the base.