梢涡空泡初生预报方法

Prediction of tip-vortex cavitation inception

应用气泡动力学方程和气泡运动微分方程研究了梢涡空泡的初生问题。建立了球形气泡平均压力模型,通过模拟梢涡流场中的球形气泡形态对梢涡空泡的初生进行预报。应用平均压力模型分别计算了三种尺度水翼梢涡流场中不同初始尺寸气泡在一定时间内的半径和辐射声压,梢涡用轴向梢涡尺寸不变的兰金涡代替。计算结果表明:从光学法和声学法角度选取空化初生判断标准可以预报梢涡空泡的初生空泡数;预报结果表明不同尺度空泡初生换算准则基本符合实验确定的相似准则。

This paper dealt with the tip vortex cavitation inception by using the bubble dynamics equa- tion and the bubble motion equation, and established a spherical bubble average pressure model. The tip vortex cavitation inception was predicted by simulating the spherical bubbles in the tip vortex flow field. Bubble size and emitted acoustic pressure shown in a certain time were calculated for various ini- tial nuclei sizes and tip vortex of three scaled hydrofoils. The tip vortex flow field was represented by a Rankine vortex with constant vortex core size. The results indicate that the tip vortex cavitation in ception can be predicated by using different cavitation inception criteria based on optical or acoustical techniques and that the scaling power deduced from the prediction agrees well with the scaling law established in the experiment.