Effect of Multiple Injection Strategies on Combustion and Emission Characteristics in a Diesel Engine

Abstract

This paper presents an experimental and numerical investigation on the spray and combustion characteristics in a common rail diesel engine with two different multiple injection strategies involving a fixed injection interval (double injection strategy) and a fixed second injection timing (split injection strategy). In this study, the double injection strategy had a fixed 10° interval with before top dead center (BTDC) 40°, 30°, and 20° of first injection timing. The split injection strategy consisted of a two-stage injection, in which the second injection timing was fixed at top dead center (TDC), followed by a first injection that varied in timing from BTDC 40–10°. A high-pressure chamber with a maximum pressure of up to 4 MPa was used to analyze the spray characteristics of the various injection strategies at high ambient pressures. Spray images were obtained using a spray visualization system to analyze the spray behavior with multiple injection conditions. The KIVA-3V code was coupled with a reduced n...