Abstract: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 400K is injected in the tangent direction into the ambient gas at 900 K, the best spray characteristics can be achieved. |