Steady Flow Analysis of the Scavenging Process in a Loop Scavenged Two- Stroke Cycle Engine–A Theoretical and Experimental Study
With the increasing design potential of computational fluid dynamics to the scavenging process of two stroke cycle engines, a detailed knowledge of the scavenging port efflux flow is essential. This paper describes the design of a two port, two-stroke cycle test cylinder that permits optical access, for laser doppler anemometer measurements, both in the cylinder and at the port boundaries. The Scavenging Efficiency-Scavenge Ratio characteristics of the test cylinder are presented along with measurements of steady state mass flow as functions of port opening and pressure drop across the port. Using laser doppler anemometry, results are presented for the port efflux flow characteristics at different port openings under steady flow conditions. The test results indicate that the flow into the cylinder does not enter in the port design direction at any given port opening. The in-cylinder flow has been modelled using a computational fluid dynamics package.