Simulation Studies on the Transition from Simple Expansion Chamber Muffler to Tapered Expansion Chamber Muffler

The pressure waves escape from the engine exhaust with a high velocity, producing an offensive exhaust noise. A properly designed exhaust silencer/muffler is helpful to reduce exhaust noise. In this paper, the effect of the shape variation in expansion chamber on the transmission loss of a reactive muffler (In line type) has been presented. The purpose of this paper is to evaluate the performance of the tapered expansion chamber muffler. The transfer matrix method is used for the evaluation of the transmission loss of the muffler. In addition, this paper discusses the shape variation from simple expansion chamber to tapered expansion chamber. The results revealed that as the area of tapered expansion chamber muffler approaches to the area of simple expansion chamber muffler, the transmission loss of both the mufflers become equal. Therefore, reactive muffler having combination of both designs can give the better performance.