缸内直喷汽油机旋流喷射喷雾特性影响因素的分析研究

Analyze and Research Affecting Factors of Spray Characteristics from High-pressure Swirl Nozzle on Gasoline Direct Injection Engine

为了研究影响缸内直喷汽油机高压旋流喷嘴喷雾特性的因素,对高压旋流喷射初始阶段运动进行了理论分析研究,确定了影响初始喷雾旋流体运动的无量纲参数。通过试验改变空心旋流体内外压差、初始旋流强度、旋流体油膜厚度,发现喷雾特性呈不同的变化趋势。随着旋流体内外压力差的增大,喷雾锥角明显减小而贯穿度变化不大;旋流强度增加,喷雾贯穿距离明显增加,而喷雾锥角变化不大;增加旋流体初始厚度,可以使喷雾在自由空间中外形尺寸增加。

To study affecting factors of spay characteristics from high-pressure swirl nozzle on gasoline direct injection engine,the initial stage of the swirl motion is theoretically researched.The dimensionless parameters affecting spray characteristics have be found.Through the experiments,variable pressure difference between outer and inner surface of the swirl jet,vortex strength and fuel film thickness can result in different spray characteristics.Increasing pressure difference between outer and inner surface of the swirl jet,spray cone angle decreases obviously but spray penetration is relatively less affected.With the stronger vortex strength,it can be found that the spray penetration is increased,but spray cone angle have a little change.Increasing fuel film thickness,spray contour is become bigger.