A Three-Zone Scavenging Model for Two-Stroke Uniflow Engines

Abstract

A three-zone scavenging model for two-stroke uniflow engines was developed and used in conjunction with a control-volume-type engine simulation code for performance prediction of long stroke uniflow-type marine engines. In this model it is attempted to simulate the three different regions perceived to exist inside the cylinder during scavenging, namely the air, mixing, and combustion products regions, by modeling each region as a separate control volume. Two time-varying coefficients are used to specify the rates of entrainment of the air and the burned gases into the mixing region. Results of the use of the model for predicting the performance of a large marine two-stroke engine are presented.