Numerical simulation for the tip leakage vortex cavitation
Numerical simulation for the tip leakage vortex cavitation
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DOI：
10.1016/j.oceaneng.2017.12.057
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发表时间：
2018-03
影响因子：
5
通讯作者：
Q. Guo;Lingjiu Zhou;Zhengwei Wang;Meng Liu;Huan Cheng
中科院分区：
文献类型：
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作者：
Q. Guo;Lingjiu Zhou;Zhengwei Wang;Meng Liu;Huan Cheng
采用商用雷诺平均Navier-Stokes（RANS）求解器研究了叶尖泄漏涡（TLV）空化。在NACA 0009水翼上的参考试验被用来验证数值模拟。考虑到旋涡流动的局部旋转特性，采用旋转曲率修正的剪切应力输运模型（SST-CC模型）模拟时均湍流流动。与原来的SST模式相比，SST CC模式改善了对下游实测断面TLV速度的预报，并对TLV轨迹沿着的涡量和压力特征进行了数值分析。为了提高TLV空化的预测精度，在参考实验的基础上对Zwart空化模型中的经验凝结系数Fc进行了标定。通过引入一个与应变率张量和涡量张量有关的涡识别参数f_（？），建立了F_（？）与空泡的关系，并在一个修正的Zwart空泡模型中体现了涡的旋转运动对空泡的影响。与传统的Zwart空化模型相比，改进后的空化模型显著改善了TLV空化的预测效果，并在不同间隙宽度的不同工况下与参考试验结果吻合较好。
The tip leakage vortex (TLV) cavitation is investigated by a commercial Reynolds averaged Navier-Stokes (RANS) solver. A referenced test on a NACA0009 hydrofoil is used to validate the numerical simulation. Considering the local rotation characteristics of the vortical flow, a rotation-curvature corrected Shear-Stress-Transport model (SST-CC model) is applied to simulate the time-averaged turbulent flow. Compared to the original SST model, the SST-CC model improves the prediction of the velocity in TLV on the measured sections in downstream, and the vorticity and pressure features along the TLV trajectory are analysed numerically. In order to increase the prediction accuracy for the TLV cavitation, the empirical condensation coefficient (Fc) in Zwart's cavitation model is calibrated based on the referenced experiment. By introducing a vortex identification parameter (f∗) related to the strain rate tensor and the vorticity tensor, a relationship between theFcandf∗is built, and the effects of the rotational motion of the vortex on the cavity are embodied in a modified Zwart's cavitation model. Compared to the conventional Zwart's cavitation model, the modified cavitation model significantly improves the prediction of the TLV cavitation and gets a better agreement with the referenced test on different conditions with various gap widths.