Simulation Research of Natural Gas Injection Timing on Combustion Process in a Diesel Engine Fueled with Pilot-Ignited Directly-Injected Natural Gas

Abstract

The numerical model of diesel engine fueled with pilot-ignited directly-injected natural gas is built, and the influence of natural gas injection timing on the combustion process is studied using CFD software. And obtained the following conclusions, as the delay of natural gas injection timing, the maximum of the mean pressure and mean temperature decrease gradually and the timings for the maximum value increase. With every delay of 5 °CA of the injection, the mean pressure reduces by about 16%.As the delay of injection timing, the delay of the timing of the high temperature and the range decrease for the high temperature region, and this is beneficial for the emission of NO, but not conducive to the emission of HC、CO and PM

The Effect of Ignition Parameters on the Combustion Characteristics of an Aviation Piston Engine

“…The increase in ignition energy accelerated the formation of the flame nucleus and shortened the flame development period [13]. Liu Yirong established a three-dimensional simplified model and studied the influence of different ignition system parameters on the combustion process of the engine through simulation, preliminarily determining the optimal parameters of the ignition system [14].…”

Investigation of the Combustion Kinetics Process in a High-Pressure Direct Injection Natural Gas Marine Engine

“…In order to further understand the combustion process for HPDI engines, numerous efforts have been performed to investigate the effects of various injection and air-exchange strategies on the engine performance and emission characteristics. ,− The combustion process of HPDI engines is more complicated than traditional diesel and gasoline engines. − To get better understanding of the combustion process, it is essential to well reveal the detailed in-cylinder combustion process. Optical diagnostics techniques have been playing a significant role in visualizing the engine flow, spray, combustion, and emission formation processes, which contributes to the development of fluid dynamics models (CFD) .…”