Effects of intake flow and coolant temperature on the spatial fuel distribution in a direct-injection gasoline engine by PLIF technique

S Kim,Y Yan,J.M Nouri,C Arcoumanis

doi:10.1016/j.fuel.2012.10.002

S Kim, Y Yan + Show 2 more

Open Access

https://doi.org/10.1016/j.fuel.2012.10.002

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Journal: Fuel	Publication Date: Nov 28, 2012
Citations: 16	License type: other-oa

Affiliation: Silla University, City, University of London

Abstract

The spatial fuel distributions of the homogeneous and stratified charge of a high pressure 6-hole injector were examined in a single cylinder optical direct injection spark ignition (DISI) engine. The effects of in-cylinder charge motion, fuel injection pressure and coolant temperature were investigated using a planar laser induced fluorescence (PLIF) technique. It was found that in the case of homogeneous charge mode, early injection in the intake stroke generated similar fuel distributions at the crank angle of 12° BTDC regardless of the in-cylinder air motion at the coolant temperature of 90°C. In the case of stratified charge mode, the in-cylinder tumble flow played more effective role in mixture preparation than the swirl flow during the compression stroke; and the increase of the coolant temperature improved fuel evaporation; but the increase of the fuel supplying pressure could not change the pattern of the fuel vapour distribution against the expectation.

Highlights

Direct-injection of fuel to combustion chamber for gasoline engines has been considered as one of the major technical improvements on fuel economy in gasoline engines, to which the port fuel injection has been traditionally associated
Spatial fuel distributions of a high pressure 6-hole multi-hole injector at homogenous and stratified charge modes were investigated in an optical engine using planar laser induced fluorescence (PLIF) technique
The results were obtained at an engine speed of 1000rpm and the effects of in-cylinder charge motions, the engine coolant temperature and the fuel injection pressure were investigated

Summary

Introduction

Direct-injection of fuel to combustion chamber for gasoline engines has been considered as one of the major technical improvements on fuel economy in gasoline engines, to which the port fuel injection has been traditionally associated. Compare to the fuel distribution with the injection pressure of 70bar under the same condition of swirl flow, 40°C coolant temperature and at ATDC 348°CA, the spatial standard deviation of the mean image was reduced from 10% at 70bar to 9% at 120bar injection pressure; a moderate improvement in homogeneity at the higher injection pressure.

Results

Conclusion