Time-domain analysis of extended-tube expansion chamber mufflers by means of the method of characteristics

Abstract

Accurate prediction of pressure pulsations in an engine is required because of the fact that these pulsations affect the engine performance and are the prime noise generators in the 1C engine. There are two methods to analyze the exhaust system and these are: (i) time domain analysis, and fit) frequency-domain analysis. The second one is more convenient, but it lacks self-dependency. It requires prior knowledge of the source characteristics, evaluation of which is a challenge to the researchers. On the contrary, the first one is self-dependent and it provides a complete formalism to analyze the exhaust system. In this article, a computer program has been developed considering different boundary conditions for simple expansion-chamber muffler and extended-tube expansion-chamber muffler for the two-characteristics as well as the three-characteristics model. The results obtained by the present two methods have been compared with each other.