摘要
为了摸清亚超大梯度剪切混合层内直射式喷嘴的燃油雾化特性,设计了用于向亚超剪切混合流中进行燃油喷射的直射式喷嘴,建立了亚超剪切混合层中燃油雾化试验系统。利用粒子图像测速系统(PIV),对亚超大梯度混合层中油雾场进行测量。通过改变喷嘴流量、喷射角度和喷嘴数量研究不同参数对雾化特性的影响,并应用图像处理技术对亚超大梯度剪切混合层内的油雾场进行分析,总结归纳其雾化规律。试验结果显示:随着流量增大,穿透深度会随之增大,破碎后的颗粒分布峰值所对应的液滴直径会逐渐变小,雾化效果提升;相同流量条件下,喷嘴的角度改变对雾化效果有影响,顺喷和逆喷的雾化效果均好于垂直喷射;逆喷的喷射高度最高,随着流量的增长,燃料将会碰壁;顺喷条件下,随着角度的增加,穿透长度会有所增加;综合燃油轨迹边界,逆喷的效果相对较好。相同流量条件下,喷孔个数的改变对雾化效果和穿透深度的影响不大。
To find out the atomization characteristics of the direct jet nozzle in the subsonic-supersonic large velocity gradient shear mixing layer,a kind of direct injector used to inject fuel into shear mixing layer is designed and a fuel atomization test system is set up.The particle image velocimetry system(PIV)is used to measure the spray field in the subsonic-supersonic large velocity gradient shear mixing layer.The influence of different parameters on atomization characteristics is studied by changing the nozzle flow rate,injection angle and the number of injectors in the experiment.The spray field in the subsonic-supersonic shear mixing layer is analyzed by digital image processing technology to sum up the law of atomization.Experimental results show that the change of flow rate will increase the penetration depth and the droplet diameter corresponding to the peak distribution of the broken particles will gradually become smaller,thus improving the atomization effect.At the same flow rate,the atomization effect is affected by the angle change of the nozzle.The atomization effect of both downstream and upstream is better than that of the vertical injection.The injection height of the reverse injection is the highest,and the fuel will bump onto the wall with the increase of the flow rate.For downstream injection,the penetration length increases with the increase of angle.The effect of inverse injection can be obtained relatively well by observing the boundary of integrated fuel trajectory.At the same flow rate,the change of the number of nozzle has little effect on the atomization effect and penetration depth.The results provide the basis for optimizing the engine combustion chamber.
作者
宫冠吉
李建中
金武
袁丽
GONG Guanji;LI Jianzhong;JIN Wu;YUAN Li(Key Laboratory of Aero‑engine Thermal Environment and Structure,Ministry of Industry and Information Technology,Nanjing University of Aeronautics&Astronautics,Nanjing,210016,China;School of National Defense Engineering,the Army Engineering University of PLA,Nanjing,210007,China)
出处
《南京航空航天大学学报》
EI
CAS
CSCD
北大核心
2020年第5期817-824,共8页
Journal of Nanjing University of Aeronautics & Astronautics
关键词
推进系统
亚超剪切混合层
雾化特性
propulsion system
subsonic‑supersonic shear mixing layer
spray characteristics
作者简介
通信作者:李建中,男,博士,教授,博士生导师,E-mail:ljzh0629@nuaa.edu.cn。
