Discussion of finite element method on insertion loss of reactive muffler

As a main evaluation indicators of muffler,the advantage of insertion loss is intuit and utility.However,the insertion loss often depends on not only the performance of muffler itself,but also is related to the performance of the whole system device.Insertion loss is more closer to the actual in muffler performance prediction than transmission loss.Insertion loss of the reactive muffler with connection pipe is computed by applying four-parameter method and finite element method,which indicates that there are defects for one-dimensional wave theory in terms of muffler performance.Therefore an experimental model for simple muffler insertion loss measuring is established,and then the insertion loss of muffler is obtained through applying direct simulation method.The results show that insertion loss of muffler with connection pipe obtained by calculation of four-parameter method is coincidence with that by direct simulation.