Effects of wall wetting and in-cylinder fuel distribution in an advanced turbo-charged engine

Abstract

One of the proposed concepts for spark ignition engines is advanced port fuel injection (APFI), which suggests using two port injectors for each cylinder. In this research, we numerically examine the capabilities of this concept in reducing fuel consumption and increasing engine performance. The results demonstrated that the use of this concept is very effective due to the use of two injectors and the possibility of reducing the spraying time and bringing the injection start time closer to the air inlet valve opening time. The maximum amount of fuel film formed on the walls is reduced by about 75%, naturally, which leads to better and more homogeneous fuel distribution inside the combustion chamber and increases combustion efficiency. The results showed that under the same boundary conditions and engine operating point, the use of two port injectors for each cylinder leads to an increase of more than 20% of the maximum combustion chamber pressure and about 4% combustion efficiency. On the other hand, fuel film formation becomes worse in cold conditions. So in this study, the capabilities of this concept in cold conditions were investigated too. Investigations have shown that the advanced port fuel injection, unlike conventional engines, is almost insensitive to inlet temperature changes.

Keywords

advanced port fuel injection (APFI) / fuel film / fuel distribution / wall wetting / heat transfer phenomena

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