Under The Influence Of The Engine Muffler Acoustic Performance Study

Engine exhaust noise control is an important factor in vehicle noise control, so the study on account of exhaust mufflers has always been an important topic in the automotive noise control. Most studies are based on the three-dimensional finite element method to predict muffler’s performance, which is also to guide the subsequent design optimization and test. Compared to one-dimension-plane wave theory, although the three dimension numerical method has improved a lot in simulation accuracy, and reflect the transmission loss of the muffler accurately, in real situation, the engine will have no small impact on muffler’s performance, which makes biased predict outcome. Taking impact factors from engine into account when study the performance of muffler may greatly improve the accuracy of predict outcome.This paper studies the performance of muffler of a newly developed exhaust system, applying three-dimensional numerical method to predict the transmission losses of muffler and establish the combustion model of the muffler matched engine, calculated the temperature and speed of the airflow at the muffler entrance in different conditions as influencing factors, analyzed the change of actual transmission losses of muffler under the impact of engine, compared the simulation results with test to verify the accuracy of this method in predicting the actual performance of muffler after its match of engine.