Study on Exhaust Pipes with an Ejector

Abstract

When two exhaust pipes are connected with a short plain pipe or a diffuser at their open ends, it is possible to promote the scavenging of cylinders by the rarefaction waves produced in the exhaust pipes with the blow down in either of them. By measuring the pressure variations in the exhaust pipes of an air model, the effect of the short pipe or the diffuser on the energy of rarefaction waves has been investigated. Further the optimum area-ratio of the short pipe or the diffuser to the exhaust pipe to produce the maximum energy of the rarefaction wave has been theoretically calculated on the assumption that the relation of steady flow can be applied to the short pipe or the diffuser. The results obtained agree fairly well with those of the experiment.