Gas Exchange Process of Four-Stroke Spark Ignition Engines under the Condition of Partial Load at Medium or Low Speed : 4th Report

Abstract

The application limit of the cavity model for the inlet or exhaust system was investigated by comparison between predictions and experiments of volumetric efficiency in 1st report. In this paper, the application limit was examined by comparison of calculations; the predictions obtained by an unsteady model including unsteady phenomena in the inlet or exhaust manifold and those of the cavity model. Then the limit of the cavity model in throttle degree, inlet or exhaust manifold length and engine speed was clarified and it agreed with that acquired from experiments. Furthermore, this cavity model was re-confirmed to be valid for the analysis of the gas exchange process under city-driving conditions.