The spray model for the study was calibrated and the predicted penetration length showed good agreement with the experimental data. Then

the effect of swirl on the interaction of fuel spray and ambient gas

which was described by spray configuration

spray penetration length

evaporated fuel mass and Sauter mean diameter(SMD) of droplets(hereinafter referred to as SMDD)

was studied at varied spray angles. Besides

the effects of fuel temperature and ambient gas temperature on spray penetration length

evaporated fuel mass and SMDD were also studied under the influence of swirl. Finally

the best spray characteristics were achieved by a comprehensive strategy. The results show that when the swirl is opposite or perpendicular to spray orientation

it suppresses the spray penetration; when the swirl is tangent to the spray orientation

it promotes the spray penetration. The swirl enhances the interaction of fuel droplets and ambient gas

as a result

increasing the evaporated fuel mass and decreasing SMDD. With the existence of swirl motion

the fuel temperature and ambient gas temperature have little effects on the spray penetration. High fuel temperature and ambient gas temperature can promote the evaporated fuel mass

but have different effects on SMDD. When the fuel temperature increases

maximum SMDD increases

while final SMDD changes little. However

with the increase of the ambient gas temperature

both maximum SMDD and final SMDD decrease. When the fuel at 400K is injected in the tangent direction into the ambient gas at 900 K

the best spray characteristics can be achieved.