Application Of Finite Element Analysis In Design Of Reactive Muffler

One important component of automobile noise is the exhaust noise of engine that controlled mainly by installed exhaust muffler . Most of the muffler design methods developed earlier have dealt primarily with one-dimension-plane wave theory , designers' experience and experiment . One dimensional theory can not provide accurate analysis result because of the propagation of higher order modes of sound wave when higher analytic frequency is desired . For the complicated project , neither it nor experience of designers can work efficiently with experiment , and these methods are of long design period and large design cost. As a contrast, three dimension numerical method can more accurately calculate the acoustic characteristic of complicated model on computer , also has the capability to easily analyze deferent designs in shorter time and find the best one to guide the experiment,so the process of product development is speeded and more resources is saved .Therefor,With the FE software ANSYS,the performance of reactive muffler is calculated by the 3-D FEM (Finite Element method)in this thesis.The FE models of simple reactive muffler are developed under static state working condition.And then ,the acoustic characteristic of the muffler elements are studied with three different expansion ratio of the muffler.Theory and project example of the performance of muffler prediction are provided by this thesis.