Computational Study of the Effects of Injection Timing, EGR and Swirl Ratio on a HSDI Multi-Injection Diesel Engine Emission and Performance

Reductions in fuel consumption, noise level, and pollutant emissions such as, Nitrogen Oxide (NO_X) and Particulate Matter (PM), from direct-injection (DI) diesel engines are important issues in engine research. To achieve these reductions, many technologies such as high injection pressure, multiple injection, retarded injection timing, EGR, and high swirl ratio have been used in high-efficiency DI diesel engines in order to achieve combustion and emission control. However, each technology has its own advantages and disadvantages, and there is a very strong interaction between these methods when they are simultaneously used in the engine.

This study presents a computational study of both the individual effect and their interactions of injection timing, EGR and swirl ratio separately and their interaction in a HSDI common rail diesel engine using the KIVA-3V code. It was found that the calculated results agree well with the experimental data obtained and there exists a set of optimal injection timing, EGR and swirl ratio for simultaneously reduction in both NO_X and soot under a particular load.