ENHANCEMENT OF ACOUSTIC PERFORMANCE OF CENTRAL INLET AND SIDE OUTLET MUFFLERS

摘要

Single expansion chamber is one of the most basic typesrnof silencing elements used in intake and exhaust system. Arntypical reactive muffler consists of inlet tube; expansionrnchamber and an outlet tube. The plane wave based models suchrnas the transfer matrix method (TMM) can offer fast initialrnprototype solutions for silencer designers. In this paperrnconventional transfer matrix is modified so that performance ofrncentral inlet side outlet muffler can be easily investigated byrncalculating transmission loss. Transmission loss prediction byrnusing modified elements of four pole parameters shows veryrngood agreement with transmission loss by numerical predictionsrnin low and mid frequency range. By using extended inlet & sidernoutlet acoustic performance of muffler is found to improve.rnFurther modification in central inlet & side outlet muffler,rnkeeping same space constraint and adding a baffle with arnprotruding tube in the chamber is found to improve the mufflerrnperformance dramatically at low to mid frequencies.