Single Cycle Simulation Simplifies Scavenging Study

A quantitative evaluation of transient volumetric scavenging efficiency in a two-stroke engine cylinder allows both direct evaluation of possible cylinder porting configurations and a basis for computerized performance prediction. This paper describes further development of a simple liquid simulation. The single cycle test rig and possible fluids are described. Quantitative scavenging performance is compared for test cylinders with conventional Schnuerle scavenging, with simplified transfer passages for mass production, and with accentuated swirl for direct injection applications. Photographs disclose informative features of transient inflow in two test cylinders and its sensitivity to piston, port and passage details.