Correlation between pulsatile flow field and its pressure characteristics in S-shaped exhaust pipe of automotive engine

Abstract

Pulsatile exhaust flow from an automotive engine is studied to investigate the correlation between the flow field and pressure characteristics. In our experiments, the exhaust flow is generated by a four-cylinder gasoline engine in a S-shaped duct, which consists of two bends and straight part, and time fluctuations of velocity and pressure of the flow are measured by hot wire anemometry and pressure sensor, respectively. Numerical simulations are also performed with RNG k-ε model. It is shown that time fluctuations of velocity and pressure are waves which have 8 peaks and we found that the fluctuation of velocity influences on differential pressure at both bends. In present work, the relation between velocity and wall pressure in S-shaped duct is discussed.