The Acoustic Characteristics Simulation Research And Improvement Of The Automobile Exhaust Muffler

The exhaust noise is the main noise sources of vehicle and it’s belongs to the low frequency noise. In city noise source, vehicle noise occupy a large proportion, So the analysis of the acoustic characteristics of the vehicle is of great significance. In view of the vehicle exhaust noise. At present, the ways to reduce the noise is to install exhaust muffler. Both traditional muffler and new type muffler, the basic structure is the expansion chamber, perforated tube inserted and exports pipe, etc. Baseed on the basic structure of muffler, this paper analyzed of the acoustic characteristics of automobile exhaust muffler, and improvement on the performance of the muffler has important significance.The article is mainly for analysis automotive exhaust noise. At present, the analysis of the exhaust noise is difficult to form accurate theoretical accurate results. But with the development of computer technology, as well as the hardware and software of the revolutionary updates, analysis and calculation from various acoustic parameters for us to provide the powerful support, and with the help of computer simulation and thought that the plane wave theory and three-dimensional numerical method is used to calculate simple expansion chamber muffler under different structure parameters of transmission loss, using three-dimensional modeling software SOLIDWORKS and professional acoustic software SYSNOISE analysis on simple expansion chamber muffler’s acoustic performance, and analysis of the aerodynamic performance of exhaust muffler, are mostly about the pressure distribution and the influence of inlet velocity on the pressure loss, thus to evaluate muffler noise performance. The results showed that within a certain range, when increase the expansion ratio, transmission loss will also along with the increase, but the expansion ratio exceeds a certain range will produce incentive noise again, form a negative effect. Expansion chamber’s length has little effect, but it determines the frequency characteristic. Within a certain range, the influence of insert tube length on the transmission is considerable. Automobile exhaust muffler of aerodynamic characteristics not only have an effect on the acoustic characteristics of the muffler, but also influence on the performance of the engine power and fuel economy. Based on the related research contents, the structure of exhaust muffler has been optimized to improve, and The acoustic characteristics of the muffler was analyzed, as a whole to achieve the optimization of the improved muffler performance is better than that of improving the performance of the former.