Effect of combustion chamber configuration on in-cylinder air motion and combustion characteristics of D. I. diesel engine

A new combustion system for a light duty D.I. diesel engine was developed and introduced. The combustion chamber, which was used in the combustion system, has 4 concaves on the periphery of the inner wall and was called HMMS-III. This combustion chamber realized better fuel consumption and lower smoke level over a wide speed range. In this study, in order to clarify the effects of HMMS-III combustion chamber on in-cylinder air motion and characteristics, analysis of flow direction and streak line via oil film method was carried out in comparison with flat dish and re-entrant type combustion chambers. Further, measurement of in-cylinder air motion by L.D.V. and observation of mixture formation and burning process via high speed Schlieren photography were carried out. From these investigations, a particular in-cylinder air motion depending on the configuration of HMMS-III combustion chamber was recognized. and the contribution of HMMS-III combustion chamber to in-cylinder air motion and combustion characteristics was clarified.