周期性供油气助雾化直喷喷嘴雾化特性试验

Experiment on spray characteristics of periodic air-assist direct injection atomizer

对一种典型的周期性供油气助雾化直喷喷嘴的雾化特性进行试验研究,分析总结了喷油脉宽、间隔时间、喷气脉宽以及空气压力对雾化性能的影响规律.试验中使用RP-3航空煤油作用工质,使用压缩空气作为介质;用激光粒度分析仪对油雾场进行测量并进行处理分析;喷油脉宽与喷气脉宽变化范围为2～8ms,间隔时间为-2～5ms,空气压力为0.1～0.65MPa.研究结果表明:随着气油比的增加,索太尔平均直径减小,均匀程度增加,雾化性能提高;增加空气压力,可以使空气密度增加,加大空气与燃油的气动作用力,有利于雾化性能的提高;增加间隔时间也可使雾化性能有小幅度的提升;在较大的平均粒径下,更加分散的粒径分布仍然可以具有较大的均匀度分布指数.对试验数据进行分析,在较高空气压力下,得到了该周期性供油气助雾化直喷喷嘴的平均粒径的经验计算模型.

An experimental study on spray characteristics of a typical periodic air-assist direct injection atomizer was presented.Attention was focused on the effect of a series of parameters（such as duration of fuel injection,space time,duration of air injection and pressure of air） on spray characteristics.The fuel employed was RP-3,and the medium employed was compressed air.Laser particle analyzer was employed for spray measurement.Duration of fuel injection,space time and duration of air injection was changed from 2 ms to 8 ms,-2 ms to 5 ms,and 2 ms to 8 ms,respectively.The range of air pressure provided was 0.1~0.65 MPa.The results show that the performance of atomization is improved as the ratio of air and fuel is increased.The increase of air density and space time is also benificial for atomization.Additionally,the distribution uniformity index value may be greater while the range of drop-size spreads more widely and the mean diameter is higher.For condition of high pressure,mean drop size is correlated using empirical equations.