改进SA模型对翼型分离流动的数值模拟

摘要

Two-dimensional numerical simulation of airfoil $825 with Spalart-Allmaras (SA) turbulent model was presented. The simulation results were compared with the experiment results. As SA turbulent mod- el could not simulate the flow separation accurately at the rear region of the airfoil, the strongly non-equilibri- um turbulence transport nature in the separate region was analyzed. The non-equilibrium turbulence transport nature was closely related to the constant Cbl in SA model. A method of modifying the constant Cb~ was adopted in SA model, and the simulation results show that the method simulates the flow separation more accurately.%采用（CFD，ComputationalFluidDynamics）软件Fluent，选取（SA，Spalart．All—maras）模型，对风力机翼型$825进行了二维数值模拟，并与实验数据进行比较．针对sA模型不能准确预测翼型尾部流动分离的情况，分析了分离区域内湍流的强非平衡输运特性．研究表明，SA模型中系数Cb1与湍流的非平衡输运特性密切相关，进而提出了修正模型系数Cb1改进SA模型的方法，结果表明该方法能够更准确地模拟风力机翼型分离流动．