Simulation of the Mean Flow in the Cylinder of a Motored 4-Valved Spark Ignition Engine

The Computational Fluid Dynamics (CFD) code KIVA II has been applied to simulate the in-cylinder mean air motion (tumble) and turbulence levels in a motored 4-stroke single cylinder engine with pentroof combustion chamber geometry, having two inlet and two exhaust valves.

In-cylinder flow during intake and compression strokes were simulated and a comparison between computational and experimental results were made. The mean turbulent kinetic energy and tumble ratio variation during the compression stroke obtained with CFD, have been compared with computational and experimental data from published literature. The simulation shows general similarity of flow structure and magnitude with published data on engines with similar geometry and initial flow conditions in the cylinder.