Numerical Prediction of Cavitation Erosion Intensity in Cavitating Flows around a Clark Y 11.7% Hydrofoil
Numerical Prediction of Cavitation Erosion Intensity in Cavitating Flows around a Clark Y 11.7% Hydrofoil
复制标题
DOI：
10.1299/jfst.5.416
复制
发表时间：
2010
影响因子：
0.8
通讯作者：
N. Ochiai;Y. Iga;M. Nohmi;T. Ikohagi
中科院分区：
文献类型：
--
作者：
N. Ochiai;Y. Iga;M. Nohmi;T. Ikohagi
提出了一种空蚀数值预测方法。该方法对空化流中的气泡进行分析，并通过球形气泡破裂引起的冲击压力来评估空化侵蚀的强度。在本研究中，Clark Y 11.7% 水翼周围的二维空化流用于检验所提出的数值预测方法。所提出的数值方法预测非空化流、附着空化流和拟超空泡流中的空化侵蚀强度远弱于瞬态空化流中的空化侵蚀强度，并且板空腔终止附近的强度较高。这些结果与实验结果很好地吻合，并且证实了该方法通常捕获了系统侵蚀特征。此外，研究了空化侵蚀的速度依赖性，发现当气泡半径较大时，强度 I 与主流速度 Uin 之间的关系中的指数 n (I ∝ Uinn) 变大，在本研究中范围在 4.3 至 7.0 之间。根据气泡动力学，环境压力和压力增加速率随着主流速度的增加而增加，并且最大内部压力增加。因此，认为当主流速度较大时，较小的气泡会引起空蚀。
A numerical prediction method of cavitation erosion is proposed. In this method, the analysis of bubbles in cavitating flows is performed and the intensity of cavitation erosion is evaluated by the impact pressure induced by spherical bubble collapse. In the present study, two-dimensional cavitating flow around the Clark Y 11.7 % hydrofoil is used to examine the proposed numerical prediction method. The proposed numerical method predicts that the intensities of cavitation erosion in noncavitating, attached cavitating and pseudo-supercavitating flows are far weaker than the intensity of cavitation erosion in a transient cavitating flow, and the intensity in the vicinity of the sheet cavity termination is high. These results correspond well to experimental results, and it is confirmed that systematic erosion characteristics are generally captured by this method. Furthermore, the velocity dependence of cavitation erosion is examined, and it is found that the exponent n in the relation between the intensity I and main flow velocity Uin (I ∝ Uinn) becomes large when the bubble radius is large and ranges between 4.3 and 7.0 in the present study. According to the bubble dynamics, the ambient pressure and the rate of increases in pressure increase as the main flow velocity, and the maximum internal pressure increase. Therefore, it is thought that smaller bubbles cause cavitation erosion when the main flow velocity is large.