Optimization Design Of Muffler Based On MATLAB

At this stage, our country is more and more prosperous, and people are richer and richer. As a result, people want to ask for more from vehicles. In addition to a basic means of transportation, we need it to be more comfortable and quieter, and have a good sound quality. Therefore, vehicle noise control, especially exhaust noise control has become an emphasis and focus of vehicle manufacturers. Exhaust noise control is inseparable from muffler research, and this paper's research is made for that a car's noise is too high and the sound quality is poor in the process of acceleration.After studying the basic theory of exhaust noise control, the paper analyses the acoustic transfer matrixes of nine basic silencer units. For the plate with some concave holes, its transfer matrix is calculated. A muffler performance simulation system with GUI of MATLAB is built, and it not only can calculate the transmission loss and pressure loss of a muffler, but also can play noise audio and calculate the value of it. At the same time, the input and output of data can be completed by the system, as well as the data comparison.Then, by the vehicle muffler performance simulation system, the paper studies the acoustic characteristics of six anechoic structures, which are used during the work of muffler optimization, and summarizes the effects of various parameters to the performance of the structures.Finally, the paper optimizes a vehicle muffler by the system. According to the acoustic characteristics of the common anechoic structure, several optimization schemes are proposed, and the best one is selected by the comparison of transmission losses, which are calculated by the system. After the simulation and experimental validation of tailpipe noise's numerical analysis and subjective evaluation, it determines the optimization scheme is compliance with the requirements. The scheme succeeds in reducing the overall noise level of exhaust system by at least 1.7 d B(A), and the noise peaks at 1200 rpm and 2000 rpm down into an acceptable range. After optimization, the vehicle exhaust noise is improved in both numerical value and sound quality.Objective evaluation and subjective evaluation work throughout the entire process, when the paper performs the optimization of the muffler. As it analyzes the performance of the original exhaust system, the paper performs objective evaluation and subjective evaluation by analyzing the noise curve and audio gained from the test; as it simulates the tailpipe noise, the paper makes objective evaluation and subjective evaluation to the curve and audio of the noise, which is produced by GT-Power; as it performs the experimental validation, objective evaluation and subjective evaluation of the test noise are taken. In the process of muffler optimization, the integrated use of objective evaluation and subjective evaluation has an intuitive, practical and prominent effect.