A Simple Theory for Pressure Pulses in Exhaust Systems

Abstract

A simple method is presented for calculating the strength of pressure pulses transmitted through pipes with area changes or in simple branch systems. The method is based on the assumption of one-dimensional flow, otherwise the exact gas relations are employed. A number of examples of typical practical configurations were investigated both theoretically and experimentally and the results compared. With the exception of one or two cases where three-dimensional effects predominate, the agreement between the theory and the measurements was very satisfactory. The application of the theory to flow problems in internal combustion engines is discussed in some detail.