Numerical Simulation of Air Motion in the Swirl Chamber of a Diesel Engine : Effect of Connecting Port in Air Motion

Abstract

Numerical simulation was carried out to clarify three-dimensional air motion in the swirl chamber of a diesel engine. Simulations have been performed using spherical swirl chambers with different sorts of connecting ports. The results obtained are as follows. (1) Toward the end of the compression stroke, the swirling flow becomes strong. On the other hand, the flow normal to the swirling surface becomes comparatively weak. (2) According to the jet of a subconnecting port, the swirling flow in the end stage of the compression stroke becomes weak in the central part. (3) The spatial distribution of strong turbulent intensities corresponds to the strong flow field and the shear force field based on inlet flow.