摘要
为研究喷口扩张比对航空发动机离心喷嘴雾化特性的影响,对多种结构离心喷嘴开展试验研究。用工业相机捕捉油雾场形态;用多普勒激光粒度仪测量喷嘴出口液膜速度、雾化粒径;结合数值模拟得到的液膜流动情况,对雾化性能进行详细分析。研究结果表明:随着喷口扩张比的增加,雾化锥角增大,雾化粒径减小,液膜轴向速度减小;当扩张比一定时,不同压差下雾化锥角基本一致;喷嘴下游存在三个流动区域,分别为燃油射流区、射流内侧空气区及射流外侧空气区,射流内侧形成对称的空气涡;在扩张段处液膜与壁面之间会形成分离区,当扩张比较大时,液膜可绕过分离区重新靠近壁面,且扩张比越大,液膜与壁面贴合程度越高。
To study the influence of the nozzle expansion ratio on aero-engine atomization characteristics,the experimental investigation on different-structured pressure swirl injectors was conducted.The oil mist field shape was captured with industrial camera,and the velocity of the liquid fuel film and droplet size at nozzle outlet were measured by PDPA,with which numerical simulation was made to abtain fluid film flow for detailed analysis on atomization performance.The analysis results indicate that spray angle increases,droplet size decreases and axial velocity of the fuel film decreases along with the nozzle expansion ratio increase;the spray angle remains the same basically under various pressure differences when expansion ratio keeps constant;the region downstream of the nozzle can be divided into three parts,namely,fuel jet region,air region inside the fuel jet,and air region outside the fuel jet,in which a symmetrical dual-vortex structure is formed inside the fuel jet region.A detached vortex region between the fuel film and wall will be formed:when the expansion ratio is large enough,the fuel film can bypass the detached region and reapproach the wall,and the adhesion between fuel film and wall increases with the increase of expansion ratio.
作者
马乙超
何小民
周建伟
张京华
MA Yichao;HE Xiaomin;ZHOU Jianwei;ZHANG Jinghua(College of Energy and Power,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Beijing Power Machinery Reserch Institute,Beijing 100074,China)
出处
《机械制造与自动化》
2023年第2期55-59,共5页
Machine Building & Automation
关键词
航空发动机
离心喷嘴
扩张比
液膜速度
雾化特性
VOF模型
aero-engine
pressure swirl injector
expansion ratio
liquid sheet velocity
atomization characteristics
VOF model
