超音速虹吸式空气雾化喷嘴雾化影响因素实验研究

Experimental study on influencing factors of atomization for supersonic siphon air atomizing nozzle

为掌握超音速虹吸式空气雾化喷嘴雾化机理及特性,采用流体力学线性不稳定理论分析雾化机理,通过喷雾实验研究不同因素对雾化性能的影响及对比不同类型喷嘴的雾化效果。研究结果表明:随着距喷嘴出口距离增加,超音速虹吸式空气雾化喷嘴在雾滴破碎后碰撞聚合作用由强到弱,300 mm内雾滴粒径增长速率明显,300 mm外雾滴粒径增长速率较缓。随着供气压力增加,超音速虹吸式空气雾化喷嘴雾滴粒径逐渐减小,在实测距离内SMD(平均粒径)最小为17.5μm。不同供气压力下,超音速虹吸式空气雾化喷嘴随距离增加,雾滴粒径增长趋势基本一致。有效射程内供气压力为0.1~0.5 MPa时,SMD仅为17.5~31.16μm。对比实验中,超音速虹吸式空气雾化喷嘴SMD比内混式空气雾化喷嘴和X旋流型压力喷嘴小53.5%~74.0%。

In order to master the atomization mechanism and characteristics of supersonic siphon air atomizing nozzle,the linear instability theory of fluid mechanics was used to analyze the atomization mechanism,then the influence of different factors on atomization performance was studied by spray experiment,and the atomization effect of different types of nozzles was compared.The results showed that with the increase of the distance from nozzle outlet,the impact polymerization effect of the supersonic siphon air atomizing nozzle became from strong to weak after the droplets were broken.The growth rate of the droplet size was obvious within 300 mm,and the growth rate of the droplet size was slow outside 300 mm.With the increase of air supply pressure,the droplet size of supersonic siphon air atomizing nozzle decreased gradually,and the minimum SMD(average particle size)was 17.5μm within the measured distance.Under different air supply pressures,the growth trend of droplet size of the supersonic siphon air atomizing nozzle was basically the same with the increase of distance.When the air supply pressure was 0.1~0.5 MPa within the effective range,the SMD was only 17.5~31.16μm.In the comparison experiments,the SMD of supersonic siphon air atomizing nozzle was 53.5%~74.0%smaller than those of internal mixing air atomizing nozzle and X swirl pressure nozzle.