A New Multi-impingement-Wall Head Diffusion Combustion System (NICS-MH) of a DI Diesel Engine - The Effect of Combustion Chamber Geometry

The multi-impingement-wall head (MIW head) is designed to be located at the center of combustion chamber and is attached to the cylinder head. In this paper, a new concept of the MIW head has been investigated to obtain a three-dimensional diffusion spray for improving the combustion and performance of a DI diesel engine.

Four Types of combustion chambers, the troidal type used in a normal DI diesel engine, and the reentrant types with a projection, with a cutouts, and their combinations (with both projection and cutouts) have been used in the NICS-MH engine experiments. Based on the experimental results of engine performance, it shows that the reentrant type of combustion chamber with a projection and a cutouts has a better fuel consumption and produces lower harmful exhaust gases (HC, NOx and smoke) than those of other NICS-MH engines. Moreover, compared with a normal DI diesel engine, the density of harmful exhaust gas of this combination type of reentrant combustion chamber is also decreased.