Effect of Combustion Chamber Geometry on In-Cylinder Flows and Equivalence Ratio Spread in a Direct Injection Engine – A CFD Analysis

摘要

In this study, a CFD analysis to evaluate effect of combustion chamber geometry on in-cylinder fluid flows and equivalence ratio spread in a Direct Injection Spark Ignition Engine (DISI) during intake and compression stroke has been carried out. The analysis has been carried out using "STAR-CD es-ice" software for four piston top profiles viz., flat piston, flat piston with a centre bowl, dome piston with a central bowl and pent roof type piston with an offset bowl at an engine speed of 1000rpm. For meshing the geometric model, polyhedral trimmed cell are adopted. The solution is obtained by solving conservation of mass, momentum and energy equations using SIMPLE algorithm. From the results, it is found that for DISI engine, flat piston is best suitable.