Combustion Analysis Techniques for Development of Next-generation Engine Systems

Yoshihiro Sukegawa Kazuhiro Oryoji Eiji Ishii, Dr. Eng. OVERVIEW: Improving the fuel economy and emissions of vehicle engines requires a detailed understanding of the various physical processes taking place inside the engine so as to identify optimal combustion control techniques and engine component designs. Based on numerical techniques established by its power plant business for the analysis of two-phase flow, combustion, and other phenomena, Hitachi has developed techniques for using simulations to estimate flow, mixture formation, and combustion in engine cylinders. Hitachi has also combined these estimation techniques with a concentration physical simulation model for PM such as soot, an area in which there has been strong demand for emission reductions in recent years. This model calculates the process of PM formation based on detailed chemical reaction mechanisms. Hitachi has gone on to use this new combustion simulation technique to propose a combustion control concept that reduces emissions at cold engine start-up.