张德胜, 吴苏青, 施卫东, 潘大志, 姚 捷, 张光建. 不同湍流模型在轴流泵叶顶泄漏涡模拟中的应用与验证[J]. 农业工程学报, 2013, 29(13): 46-53. DOI: 10.3969/j.issn.1002-6819.2013.13.007
    引用本文: 张德胜, 吴苏青, 施卫东, 潘大志, 姚 捷, 张光建. 不同湍流模型在轴流泵叶顶泄漏涡模拟中的应用与验证[J]. 农业工程学报, 2013, 29(13): 46-53. DOI: 10.3969/j.issn.1002-6819.2013.13.007
    Zhang Desheng, Wu Suqing, Shi Weidong, Pan Dazhi, Yao Jie, Zhang Guangjian. Application and experiment of different turbulence models for simulating tip leakage vortex in axial flow pump[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2013, 29(13): 46-53. DOI: 10.3969/j.issn.1002-6819.2013.13.007
    Citation: Zhang Desheng, Wu Suqing, Shi Weidong, Pan Dazhi, Yao Jie, Zhang Guangjian. Application and experiment of different turbulence models for simulating tip leakage vortex in axial flow pump[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2013, 29(13): 46-53. DOI: 10.3969/j.issn.1002-6819.2013.13.007

    不同湍流模型在轴流泵叶顶泄漏涡模拟中的应用与验证

    Application and experiment of different turbulence models for simulating tip leakage vortex in axial flow pump

    • 摘要: 为寻求一种经济、适合的湍流模型模拟轴流泵叶顶泄漏涡的结构和运动特性,该文基于ANSYS CFX软件平台,优化了六面体网格拓扑结构,比较了标准k-ε湍流模型(standard k-ε)、重正化群k-ε湍流模型(renormalization group k-ε,RNG),标准k-ω湍流模型(standard k-ω)和SST k-ω湍流模型(shear stress transport)等4种湍流模型在轴流泵叶顶泄漏涡模拟中的计算精度和叶顶泄漏涡流场特征。数值模拟和试验结果表明,在最优工况下,SST k-ω湍流模型预测外特性曲线与试验曲线吻合较好,扬程误差为4.688%,较其他3种湍流模型准确;4种湍流模型计算的叶顶泄漏涡流线、叶顶区压力场和轴面速度场分布规律相似,但RNG k-ε和SST k-ω湍流模型计算的涡卷吸较强,涡带的旋涡强度相对较大。基于旋涡强度提出了一种对叶顶泄漏涡的涡心进行识别的方法,并与高速摄影拍摄的涡带结果进行了对比,在设计流量工况和大流量工况下,发现SST k-ω湍流模型计算的叶顶泄漏涡运动轨迹与试验结果吻合度较好,验证了SST k-ω湍流模型在轴流泵叶顶泄漏涡模拟具有较好的适用性。

       

      Abstract: Abstract: In order to explore a turbulence model to simulate the structure and the kinetic characteristic of the tip leakage vortex suitably, the study was conducted based on the ANSYS CFX soft and high-speed imaging experiment. The topology structure of the simulation domain was optimized with 20 layers in a blade tip region that got more flow information in the tip area. As a result, simulation requirements are met, while reducing the calculation time. The flow field characteristic, especially the tip leakage vortex simulated by four kinds of turbulence models, which are standard k-ε, renormalization group k-ε, standard k-ω, and shear stress transport k-ω, was compared and analyzed. The simulation and the experiment results showed that the external characteristic curve predicted basing on the SST k-ω model is in substantial agreement with the experiment curve, and the deviation of the head is about 4.7% in the operating condition, which is better than the others; Head error based on standard k-ω model had a little less than others. The distribution law of the streamlines of the tip leakage vortex predicted basing on the four models was similar, as well as the pressure field and the axial velocity in the blade tip area. However, the length of the low-pressure area computed by RNG k-ε was longer than other 3 models. The counter velocity narrow region based on the RNG k-ε and SST k-ω was bigger than others, and the vortex entrainment was stronger too. The identification of the vortex core based on vortex intensity was established and compared with the results by the high-speed imaging. The motion trajectory of the tip leakage vortex based on different turbulence was different. It moves up when simulated in a big working operation. The motion trajectory of the tip leakage vortex based on SST k-ω is in substantial agreement with the experiment by comprehensive comparison. Via the above study, the adaptability of the SST k-ω model in the tip leakage vortex simulation was determined to be the best turbulence model among these four turbulence models, so the SST k-ω model is recommended when studying the tip leakage vortex in axial flow pumps.

       

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