关键词: 熵产;数值模拟;水翼;空化

Abstract: In order to make directional and quantitative evaluation of the energy loss in cavitation flow, the entropy production theory was introduced to analyze the cavitation flow around a two-dimensional hydrofoil. The NACA0009 airfoil was chosen as the numerical model, the - turbulence model and ZGB cavitation model were adopted to simulate the characteristics of the hydrofoil. The numerical results were verified by the experimental datas. The results show that there is a clear correlation between entropy production and airfoil dynamics, for the energy loss and entropy production change rapidly when the lift coefficient and drag coefficient change suddenly. The turbulent dissipation entropy production always accounts for more than 80% of the total entropy production, and in large cavitation number the wall friction entropy production accounts for 10% and so can not be ignored. The energy loss is centrally distributed at the rear portion of the cavity region and the trailing edge of airfoil. When the cavitation number is between 0.6 and 0.4, the cavity will shed periodically in large scale, leading to the higher energy loss generated in the flow field. However, when the cavitation number was lower than 0.4, the cavity is more stable and so the flow field becomes more stable and the energy loss decreases. The analysis show that the entropy production theory can be applied to the analysis of cavitation flow.

Key words: Entropy production;Numerical simulation;Hydrofoil;Cavitation