双级旋流空气雾化喷嘴一次雾化数值模拟  

Numerical simulation of primary atomization for dual-stage swirl airblast atomizer

作　　者：游云霞 范周琴 陈伟强 曹程 孔凡夫 YOU Yunxia;FAN Zhouqin;CHEN Weiqiang;CAO Cheng;KONG Fanfu(Aerospace Technology Institute,China Aerodynamics Research and Development Center,Mianyang 621000,China;Laboratory of Light-Duty Gas-Turbine,Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China;School of Aeronautics and Astronautics,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国空气动力研究与发展中心空天技术研究所,绵阳621000 [2]中国科学院工程热物理研究所轻型涡轮动力全国重点实验室,北京100190 [3]中国科学院大学航空宇航学院,北京100049

出　　处：《航空学报》2024年第S1期133-147,共15页Acta Aeronautica et Astronautica Sinica

基　　金：国家科技重大专项(J2019-III-0005-0048);国家自然科学基金(91941301)

摘　　要：目前对双级旋流空气雾化喷嘴的研究以试验为主,无法解释其雾化机理及演化过程,为掌握双级旋流空气雾化喷嘴的燃油混合和分布特性,阐明燃油射流在不同燃烧室来流工况下的雾化机理,采用RANS湍流模型耦合VOF模型、VOF-to-DPM模型,结合自适应网格技术,开展了包含燃油流体域、空气流体域的全流体域一次雾化数值仿真模拟,模拟结果成功捕捉到了离心喷嘴和文氏管壁上液膜形成及破碎成液丝、液滴的过程。与试验结果进行对比,喷雾锥角最大误差仅为1.34%,出口液膜破碎长度均为0.8 mm,验证了模拟结果的正确性。对比分析了有无旋流空气作用下离心喷嘴的雾化特性,发现一次旋流空气会引起出口液膜的周期性振荡,可增大喷雾锥角、缩短破碎长度,但增大了液膜厚度,进而降低了离心喷嘴出口液膜速度。研究了旋流器空气压降、来流压力和温度、燃油流量对双级旋流空气雾化喷嘴喷雾锥角及索特尔平均直径(SMD)的影响,结果表明:随着旋流器空气压降增大,雾化锥角增大,SMD减小;随着来流压力和温度增大,喷雾锥角增大后趋于平衡,SMD先减小后增大再减小;随着燃油流量增大,雾化锥角先增大后减小,SMD呈减小趋势。本文研究发展了双级旋流空气雾化喷嘴在全流体域上的数值仿真模拟,为更好地理解该型喷嘴的演化过程和雾化机理提供了理论支撑。The current research on the dual-stage swirl airblast atomizer is primarily experimental and cannot explain the atomization mechanism and evolution process.To master the fuel mixing and distribution characteristics of the dual-stage swirl airblast atomizer,and clarify the atomization mechanism of fuel jets under different combustion cham⁃ber inflow conditions,RANS turbulence model coupled with VOF and VOF-to-DPM model were adopted in this paper.Combined with adaptive grid technology,the numerical simulation of primary atomization in the whole fluid domain,in⁃cluding fuel fluid domain and air fluid domain,was carried out.The process of liquid film formation on the pressure swirl atomizer and the wall of the Venturi tube and the process of breaking into filaments and droplets were successfully captured in the results.Compared with the experimental results,the maximum error of spray angle is only 1.34%,and the breakup length of liquid film at the outlet is consistently 0.8 mm,which verifies the correctness of the simula⁃tion results.The atomization characteristics of the pressure swirl atomizer with and without swirling air were compared and analyzed.It was found that the primary swirling air will cause periodic oscillation of liquid film at the outlet of the pressure swirl atomizer which can increase the spray angle and shorten the breakup length.However,it also in⁃creases the liquid film thickness,thereby reducing the velocity of liquid film at the outlet of the pressure swirl atomizer.The effects of air pressure drop,inlet pressure and temperature,and fuel flow rate on spray angle and Sauter Mean Diameter(SMD)of the dual-stage swirl airblast atomizer were analyzed.The results show that as the air pressure drop across the swirler increases,the spray angle increases,and SMD decreases.As the inlet pressure and tempera⁃ture increase,the spray angle increases and then tends to balance,and SMD decreases first,then increases and fi⁃nally decreases.Additionally,as the fuel flow rate increases,the spray angle

关 键 词：双级旋流空气雾化喷嘴 燃油演化 一次雾化 全流体域 雾化特性 

分 类 号：V231.23[航空宇航科学与技术—航空宇航推进理论与工程]