Noise Elimination Reserching Of Muffler Based On Emission And Acoustics Characteristics

With the rapid development of motorcycle industry, Motorcycle production and motorcycle retention get an exponential ramp. Motorcycle has become an indispensable transport means of human beings.But, motorcycles aslo bring some safety problems and environmental pollution at the same time. noice pollution is one of the environmental pollution caused by motorcycle and it has already drawn widespread attention from the whole society. How to reduce the noice of motorcyle has become a serious problem to be solved immediately.The exhaust noise is the most important noise source of the motorcycle. And muffler was used to control the exhaust noise effectively. In order to abate noise pollution, studying acoustic performance of exhaust muffler for motorcycle and its improving is of great importance to society and application.Based on the present investigation of muffler, a numerical emulated research on exhaust muffler of LX150/LX125 motorcycle is made by using software of"ANSYS"and"SYSNOISE/GT-POWER"combinedly, and the effect of structural parameter on muffler's acoustic performance is analyzed by the same way. Besides, the special motorcycle and muffler is measured, and its acoustic performance is analyzed by program of"MATLAB". Consistency can be displayed by comparing the muffler's test with that of numerical analysis. Then, the drawback of the muffler can be showed by observing these outcomes—the graphs of transmission loss and exhaust spectrum: the performance of the muffler is poor at low-frequency, and there are several through- frequency. Against these drawbacks, some improving design is done: adding a Helmholtz-resonator as the forth cavity, adding a short perforate pipe at the tail tube.Transmission loss and pressure loss are main evaluating indicators in the process of comparing the old and improved muffler. Then it is displayed that the performance is improved obviously. So the expected result is reached.This method can shorten the test-period of muffler and reduce its cost. And it is alsoconvenient, fast and illustrated. Moreover, improving design against its weakness can be done by this method which is significant to boosting the level of designing and analyzing exhaust muffler.