基于B样条网格的三维水翼水动力性能研究

The investigation of hydrodynamic performance for three-dimensional hydrofoil based on B-spline grid

该文应用低阶速度势面元法建立了预报三维水翼水动力性能的数值方法,重点对翼梢和尾涡进行了研究。文中采用基于B样条的网格划分方法,在水翼前缘处的弦向网格线与外轮廓线正交,在尾缘处与尾涡离开的速度方向相一致。翼梢上尾涡分离点的位置采用迭代的方法进行确定。对于三维升力问题而言,横向流动的影响作用很大,本文对现有的库塔条件形式进行了改进,在考虑横流影响的前提下,满足随边荷载为零的条件。通过对计算结果与试验结果进行比较表明,将基于B样条的网格划分方法及改进的库塔条件应用于已有的面元法程序中,能够很好地改善计算结果的精度。

A potential-based surface panel method is applied to predicting the performance for three-dimensional hydrofoils, with emphasis on the tip region. A new panel arrangement, by using B-spline method, is utilized. The grid is normal to the leading edge outline and in accordance with the wake direction at the trailing edge. The detachment point is determined by process of iteration. For three-dimensional problems with significant effect of cross flows, a new form of pressure Kutta condition is proposed to satisfy the zero loading condition at the trailing edge. The computation result shows that when the new grid arrangement and Kutta condition are applied in the existing surface panel method, the accuracy of calculation result can improves substantially.