摘 要：【目的】处于均匀流场之中的水下翼型，当空泡数下降到某一临界值后，会使其前缘位置压强低于饱和蒸汽压，进而发生初生空化。在模型试验研究翼型水动力和空泡性能过程中，由于模型尺度的翼型难以满足实尺度翼型的雷诺数，使翼型表面边界层厚度以及周围流场分布发生了改变，进而使空化起始对应空泡数的大小发生改变。【方法】本文以航速为24节的标准KCS船采用的NACA0012型船舵为参照，基于STARCCM+软件，采用SST k-ω湍流模型和Schnerr-Sauer(S-S)空化模型进行翼型空泡特性数值模拟。针对不同缩比模型，改变不同攻角工况下的翼型的环境压强计算翼型表面流场和空泡分布，得到空化起始所对应的空泡数的大小，分析尺度效应对临界空泡数的影响机理。【结果】经过计算结果分析得出：随着缩比的增大尺度的缩小，翼型对应攻角下的临界空泡数的大小会有一定程度的减小，说明因雷诺数差异带来的尺度效应加剧。【结论】因此在模型试验中，为防止尺度效应对起始空泡数的影响，不宜选用较小尺度的翼型进行试验。
Abstract: [Objectives] For an underwater hydrofoil in a uniform flow field, when the number of cavitation decreases to a certain critical value, the pressure at the leading edge of the hydrofoil will be lower than the saturated vapor pressure, and then cavitation initiation will occur. In the process of model test to study the hydrodynamic and cavitation performance of hydrofoils, because the model-scale hydrofoils are difficult to meet the Reynolds number of real-scale hydrofoils, the thickness of the boundary layer on the hydrofoil surface and the distribution of the flow field around the hydrofoils are changed. thus, the size of the critical cavitation number during primary cavitation is changed. [Methods] In this paper, with reference to the NACA0012 rudder used in the standard KCS ship with a speed of 24 knots, the hydrofoil cavitation characteristics were numerically simulated by using SSTk- ω turbulence model and Schnerr-Sauer (S-S) cavitation model based on STARCCM+ software. According to different scale models, the surface flow field and cavitation distribution of hydrofoils were calculated by changing the environmental pressure of hydrofoils at different angles of attack, the critical cavitation number corresponding to cavitation initiation was obtained, and the influence mechanism of scale effect on critical cavitation number was analyzed. [Results] Through the analysis of the calculation results, it is concluded that with the increasedecrease of the scale ratio, the size of the critical cavitation number at the corresponding angle of attack of the hydrofoil will decrease, indicating that the scale effect caused by the difference of Reynolds number is intensified.[Conclusions] Therefore, in the model test, in order to prevent the effect of scale effect on the initial cavitation number, the hydrofoil with smaller scale should not be selected for test.