A Study of the Characteristics of Mixture Formation and Combustion in a PCCI Engine Using an Early Multiple Injection Strategy

Abstract

As world attention has focused on global warming and air pollution, high-efficiency diesel engines with low CO2 emissions have become more attractive. Premixed diesel engines in particular have the potential to achieve a more homogeneous mixture in the cylinder which results in lower NOx and soot emission. It is well-known that the injection strategies such as the injection timing and the spray included angle are important to create the optimal mixture formation for a PCCI (premixed charge compression ignition) engine. In this research, we investigated the effect of injection angle, injection timing, and frequency on the combustion and mixture formation in a direct injection type PCCI engine using an early multiple injection strategy. The experimental results showed that the mixture formation, IMEP, and emission characteristics in the PCCI engine were dominantly affected by the fuel injection timing and spray included angle. In particular, the injection timing of 65° BTDC with the spray included angle of ...