航空学报 > 2024, Vol. 45 Issue (S1): 730579-730579   doi: 10.7527/S1000-6893.2024.30579

双级旋流空气雾化喷嘴一次雾化数值模拟

游云霞1, 范周琴1(), 陈伟强1, 曹程2,3, 孔凡夫1   

  1. 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
  • 收稿日期:2024-04-23 修回日期:2024-04-30 接受日期:2024-07-08 出版日期:2024-12-25 发布日期:2024-08-05
  • 通讯作者: 范周琴 E-mail:fanzhouqin830227@163.com
  • 基金资助:
    国家科技重大专项(J2019-III-0005-0048);国家自然科学基金(91941301)

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

Yunxia YOU1, Zhouqin FAN1(), Weiqiang CHEN1, Cheng CAO2,3, Fanfu KONG1   

  1. 1.Aerospace Technology Institute,China Aerodynamics Research and Development Center,Mianyang 621000,China
    2.Laboratory of Light-Duty Gas-Turbine,Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China
    3.School of Aeronautics and Astronautics,University of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2024-04-23 Revised:2024-04-30 Accepted:2024-07-08 Online:2024-12-25 Published:2024-08-05
  • Contact: Zhouqin FAN E-mail:fanzhouqin830227@163.com
  • Supported by:
    National Science and Technology Major Project(J2019-III-0005-0048);National Natural Science Foundation of China(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。

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

Abstract:

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 chamber 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, including 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 simulation 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 increases 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 temperature increase, the spray angle increases and then tends to balance, and SMD decreases first, then increases and finally decreases. Additionally, as the fuel flow rate increases, the spray angle increases first and then decreases, and SMD shows a decreasing trend. In this paper, the numerical simulation of the dual-stage swirl airblast atomizer in the whole fluid domain is developed, providing theoretical support for a better understanding of the evolution process and atomization mechanism of this type of atomizer.

Key words: dual-stage swirl airblast atomizer, fuel evolution, primary atomization, whole fluid domain, atomization characteristics

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