一种抗空化翼型修形设计方法

A Reshaping Method for Anti-cavitating Hydrofoil Design

为提高水翼抗空化性能,对二维翼型的吸力面外形进行适当改造.通过集成几何参数化技术、面元法和优化算法构建了翼型抗空化优化设计方法.翼型的修形采用在吸力面上设立一段拱弧的方法,并运用三次B样条对翼型进行了参数化表达.在某一工况下,以面元法预报的翼型性能参数作为遗传算法建立目标函数的依据,进行了针对NACA0010翼型上设立拱弧的最佳参数的单一目标和多目标寻优.同时运用雷诺平均纳维艾斯托克斯方法结合RNG k-ε(Re-normalization group k-ε)湍流模型对原翼型及改型的空化流场进行瞬态模拟,对比了气体体积分数云图的差异.结果分析表明.修改的翼型较原型对空化的发展有一定抑制作用,达到了预期目的.

In order to improve the anti-cavitating performance of the hydrofoil, the suction side of the two- dimensional foil was transformed. By integrating the technology of the geometric parameterization with the panel method and the optimization algorithm, the hydrofoil was reconstructed with anti-cavitating consid- eration. The modification was achieved by setting up a vaulting barrier on the suction side of the section and using cubic B-spline to parameterizedly express the shape. The basis data for the genetic algorithm ob- jective function which was founded for the NACA0010 airfoil optimization, were accessed by the panel method program in forecasting the foil performance under a certain condition. The instantaneous simula- tion of the prototype and the modified foil flow with cavitating were conducted by using RANS method and RNG κ-ε turbulence model. The differences between the contours of gas volume fraction, which reflects the degree of foil in cavitating, were acquired. The result confirmed the intended purpose of the modifica- tion. This hydrofoil design method provided reference for the three-dimensional hydrofoil design.