Flow Characteristics of An Unsteady Jet Ejected into A Prechamber Spark Ignition Engine

Abstract

An unsteady jet flow ejected from the main chamber to the prechamber during the compression stroke plays an important role in forming the mixture and in the ignition and combustion in the prechamber. The torch flame jet from the prechamber also has a large effect upon the combustion in the main chamber. There have been many studies on the torch jet flow [1], but most of them were applied to steady flows. There have been only a few investigations of turbulent combustion in a constant volume vessel[2–4] and on torch jet flows in a practical engine[5,6]. Recently, laser Doppler velocimeter (LDV) has been used to measure jet velocity and its fluctuation in the jet flow emitted from the main chamber to the atmosphere or to a partially confined space during the compression stroke of a motored engine[7,8].