非均匀速度来流条件下液体射流喷雾特性  

Spray characteristics of liquid jet in nonuniform crossflow

作　　者：孔祥壮 何悟[1] 郭志辉[1] KONG Xiangzhuang;HE Wu;GUO Zhihui(National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics,School of Energy and Power Engineering,Beijing University of Aeronautics and Astronautics,Beijing 100191,China)

机构地区：[1]北京航空航天大学能源与动力工程学院航空发动机气动热力国家级重点实验室,北京100191

出　　处：《航空动力学报》2022年第3期534-544,共11页Journal of Aerospace Power

基　　金：国家科技重大专项(2017⁃Ⅲ⁃0008⁃0034)。

摘　　要：实验研究了非均匀速度来流条件下液体横向射流喷雾特性。实验利用多孔板实现速度的不均匀,应用片光照相得到喷雾中心截面照片,使用相位多普勒粒子分析仪(PDPA)测量液滴的直径和速度。实验结果表明:在非均匀速度来流中,射流的弯曲和破碎机理有所不同,导致穿透深度和雾化特性发生改变。与均匀速度来流相比,正速度梯度来流时射流穿透深度更大,液柱破碎高度增大,浓度场分布更加均匀,射流呈现平抛形态;负速度梯度时喷雾场整体内移,浓度场呈明显分层结构,射流尾迹区增长,射流为坍塌形态。初步提出适用于非均匀速度来流条件下的射流穿透深度经验公式。非均匀速度来流可以改善雾化及均匀度,其中负速度梯度来流时液雾的索太尔平均直径(SMD)最小。Spray characteristics of liquid jet in nonuniform velocity distribution crossflow were experimentally studied.The nonuniform velocity distribution was produced by perforated plates,the images of spray were captured with a light sheet and a single lens reflex camera,and a phase Doppler particle analyzer(PDPA)was used to measure droplets diameter and velocity.The experimental results indicated that,in the nonuniform crossflow,the bending state and breakup regime of each jet section were different,resulting in the difference of penetration and spray characteristics.Compared with uniform corssflow,the jets penetrated further into the cross⁃flow when the column breakup height increased,and the concentration distribution was more uni⁃form when the velocity distribution was in positive gradient,in addition,the jet presented a flat thrown profile.When the velocity gradient was negative,the spray field moved inward and pre⁃sented a stratified structure,the jet wake region elongated,and the profile of jet was in collapse state.Correlations of a liquid jet for nonuniform crossflow are presented.Nonuniform crossflow can improve atomization and uniformity,and Sauter mean diameter(SMD)reaches a minimum value when the velocity distribution is negative gradient.

关 键 词：非均匀 横向流 喷雾特性 局部射流动量比 破碎机理 

分 类 号：V231.2[航空宇航科学与技术—航空宇航推进理论与工程]