Analysis of Pressure Loss and In-Cylinder Flow of a Four Strokes Engines Using CFD Modeling

The effects of valve gap of intake system on the performance of a developing engine model is numerically studied with a CFD software, STAR-CD, and experimentally verified by flow bench tests. Detailed flow structure, such as velocity features and pressure field in steady state near injector entrance chamber, along flow path at the minimum curvature radius and in the neighborhood of intake valves are thorough analyzed. The flow simulation near the exit of intake valve is conducted to interpret the roles of in-cylinder flow configuration and tumbling characteristics on enhancing the extent of tumble. The experimental results of flow coefficient are in good agreement with those of the simulation. Hence, the built-up database of engine design parameters is valuable for the design of cylinder configuration and for determining locations of probing the ideal projective of flow coefficient.