Based on a naturally aspirated single
cylinder diesel engine, the effects of nozzle hole number for direct injector on ethanoldiesel dual fuel combustion and emission were researched under different injection timings and premixing ratios by utilizing the incylinder 3D simulation and calculation. The results show that optimization of nozzle hole number can affect fuel incylinder distribution and regulate the combustion process of ethanoldiesel dual fuel engine. The reduction of nozzle hole number can lower the distribution area of high reactivity fuel, which will reduce the initial ignition positions. The maximum combustion pressure and pressure rise rate further decrease. In addition, NOx emission reduces and soot emission can keep within a low level. With the increase of ethanol proportion, the effects of nozzle hole number on combustion and emission first increase and then decrease. With the increase of fuel supply advance angle, the nozzle hole number has little influence due to the injected fuel incylinder uniform mixing.
