The Optimization Of Exhaust System Noise And Vibration

The automobile industry and traffic utility of our country is developing high-speedly,which results the amount of using automotive vehicle increasing sharply.The huge noise pollution generated from that has been an assignable factor which disturbs people’s life and pollutes environment.More rigorous regulations on limiting vehicles are put forward b y countries around the world.The exhaust noise occupies a main part of vehicle noise.The rapid and stead y development of vehicle technique makes rotational speed and consolidation of the I.C.engines increase constantly,which enlarges exhaust noise and the vibration transmitted from exhaust system and reduces the comfortbility.The design and development of NVH depends on physical model test which is also applied to noise and vibration issues.However,it costs considerable time and money.In order to avoid the waste,this paper adopts simulation to optimize exhaust noise,fuel econom y and power loss.To begin with,the exhaust system model by GT-POWER is constructed and then the exhaust noise,power loss and fuel economy can be obtained after the analysis.Optimizing the parameters and instruction with orthogonal test is the third step.Finall y the exhaust noise,fuel economy and power loss turns better than the original result.After the optimization of exhaust noise,modal anal ysis is madethrough exhaust system model to calculatethe natural frequency.Sensitive anal ysis is performed on the key parameters of exhaust system components.Based on ADDOFD method,optimize the suspension point layout.According to the result of sensitive analysis,change the natural frequency to make it far from engine driving frequency.In the end,check the feasibility b y static anal ysis.