In the present investigation due to the stringent legislation for emission of diesel engines and also increasing demand on fuel consumption, the importance of detailed 3D simulation of fuel injection, mixing and combustion have been increased in the recent years. In this regard, Computational Fluid Dynamics (CFD) technique has been identified as a very helpful tool through which the in-cylinder process can be simulated and studied before proceeding to prototyping and experimental studies.  

In this study, CFD approach was focused to investigate the effect of combustion chamber configuration on in-cylinder air motion in a DI diesel engine. Two different shapes of diesel engine combustion chamber were modeled and simulated under transient conditions using a commercial CFD code STAR-CD.  In this paper, results of detailed 3-D simulations of the two configurations of combustion chamber are presented. It has been observed that effect of combustion chamber shape on incylinder air motion was quite significant near TDC of compression which is important period with respect to combustion and pollutant formation