Abstract
To make clear the behavior of unsteady jet flow ejected into the prechamber of a motored engine, the unsteady jet flow in the prechamber are visualized at every crank angle duaring the compression stroke by spark tracing techniqe, changing the nozzle width and position of spark electrodes.
Consequently, it can be clear that the jet velocity on its center axis is always negative duaring the initial period of compression stroke from Bottom Dead Center (BDC) to about 45° in crank-angle, and thereafter, two large circluating flows are formed at both sides of the jet flow in the prechamber.
Furthermore, those jet flow patterns visualized by spark time line are showing a resonable agreement with the spatial distributions of jet velocity measured with Laser Doppler Velocimeter.
