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Numerical Analysis of Hydrodynamic Performance of Finite Span Hydrofoil

有限跨度水翼水动力性能数值分析

基本信息

批准号：
02302054
负责人：
KATO Hiroharu
金额：
$ 6.72万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Co-operative Research (A)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02302054/
关键词：
Finite Span Foil Finite Difference Method Lifting Body Theory Cavitation Free Surface Tip Vortex CFD 有限幅直進翼

项目摘要

Made were the numerical and experimental investigations on the hydrodynamic performance and flow situations of a finite span hydrofoil. The following results were obtained :The lift and drag forces and the pressure distribution obtained by the lifting body theory agreed well with those of the experiments unless the large boundary layer separation occurred on the hydrofoil surface.This theory, however, could not argue the details of the flow situations such as boundary layer and its relation to the tip vortex.Two kinds of finite difference calculations were made with a low Reynolds number of 1, 000. Some kinds of calculation conditions were selected such as with free surface and with cavitation. The results were compared and discussed in detail with the experimental ones. As a result the future works of the CFD research were clarified on the hydrodynamic study of finite span hydrofoils.The calculation of a hydrofoil under a free surface showed the wave-making due to the foil and the lift force decrease due to the free surface.It was shown that the tip vortex had two cores caused by the two boundary layers on the foil upper and lower surfaces, respectively. The rolling-up to the tip vortex and the tip vortex separation were also calculated.The calculated cavitation on the foil surface had similar appearance to that of the experiments although the quantitative agreement could not be obtained because of the large difference in the Reynolds numbers.The measurements showed that the tip vortex had a very small radius of 1% the maximum chord length and a high rotation speed of over 0.6 times the uniform flow velocity. A solution adaptive grid, multi-grid system or some modeling of the tip vortex might be required in addition to the turbulence model, in order to calculate a high Reynolds number flow and argue the tip vortex in detail.

对有限跨度水翼的水动力性能和流态进行了数值和实验研究。结果表明：除大边界层分离外，升力体理论得到的升力、阻力和压力分布与实验结果吻合较好，但该理论不能讨论边界层及其与叶尖涡的关系等流动情况的细节。选择了有自由面和有空化两种计算条件。将计算结果与实验结果进行了详细的比较和讨论。通过对水翼在自由表面下的计算表明，翼型的兴波和升力因自由面的减小而减小，叶尖涡有两个核心，分别由翼面上和下表面的两个边界层引起。计算结果表明，翼面空化的计算结果与实验结果基本一致，但由于雷诺数差异较大，计算结果与实验结果不能定量吻合。测量结果表明，叶尖涡旋的半径很小，仅为最大弦长的1%，旋转速度大于均匀流动速度的0.6倍。为了计算高雷诺数流动，并对叶尖涡进行详细的讨论，除了湍流模型之外，可能还需要求解自适应网格、多重网格系统或对叶尖涡进行某种建模。