Combustion Ignition Delay in Engines with Unconventional Piston Motions

Abstract

Ignition delay is an important parameter in determining diesel engine performance and efficiency and has a profound effect on the ability of an engine to start in cold conditions. With declining fuel quality and increasing interest in unusual fuels, this topic must be addressed for future engine designs. A literature survey has revealed that models of the type proposed by Wolfer are preferred. This model has been used to show that the piston motion in an engine can have a significant effect on ignition delay and cold-start performance. In particular, it was readily demonstrated that a sinusoidal motion (as imported by a Stiller-Smith mechanism) and an inverted slider-crank motion both offered superior performance to a conventional slider-crank motion.