影响空化流数值计算的各种因素分析

Impact Factors of Numerical Computation About Cavitating Flow

通过CFD软件实现了二维翼型定常空泡流动的数值模拟,分析了空化模型、湍流模型和壁面函数法的选取对数值模拟计算结果的影响。对不同空化数条件下的空泡流场进行详细分析,得出了各种情况下翼型表面的压强分布曲线图。分析结果表明:几种空化模型均能够较好地模拟出空泡的起始、形成过程,与实验值相符合;但在空泡闭合区域,由于空化流的脉动特性,各空化模型之间的计算结果有所差别。RNGk-ε湍流模型和RSM湍流模型的计算结果比较一致,且与实验值吻合得较好;而标准k-ε模型的结果与实验值存在较大的偏差。采用增强壁面函数法的计算结果与实验值吻合得最好;而标准壁面函数法和非平衡壁面函数法的计算结果非常相近,但与实验值有一定的差距。

Steady cavity flow of 2-D hydrofoil is simulated by CFD software.The impacts of different cavitation models,turbulence models and wall functions to the numerical simulation results are analyzed.The pressure distributing curve is obtained through the detailed analysis to the cavity flow under different cavity number.The analysis results show that those cavitation models simulate the origination and forming process of cavity preferably,which match experiment values closely.However,there are some differences between the results of those different cavitation models in the cavity closing area.The results of RNGk-εmodel and the RSM model are more uniformity with the experiment values,but there is large distinctive between the result of the standard k-ε and the experiment values.The results of the standard wall function are close to the non-equilibrium wall function which have distinction with the experiment values,but the enhanced wall function is the most accurate.