非线性双方程湍流模型用于rn翼型分离流动模拟

摘要

采用非线性k-和q-ω双方程湍流模型，利用高收敛率、高精度和高分辨率的数值算法，对二维NREL S809翼型在0～18°攻角范围内的低速绕流进行了数值模拟，将翼型的升阻特性的计算值与实验值进行了比较。与采用线性k-和q-ω双方程湍流模型的计算结果对比表明，当翼型流动发生分离时，采用非线性双方程湍流模型可以明显地改进计算精度。本文采用的数理模型与数值方法可有效地用于风力机翼型大尺度分离流场的预测。%Numerical simulation of the turbulent flow fields at stall conditions are presented for the NREL(National Renewable Energy Laboratory)S809 airfoil.The flow is modeled as compressible,viscous,steady and turbulent.Four two－equation turbulence models,i.e.isotropic k－ model,isotropic q－ω model,anisotropic k－ model and anisotropic q－ω model，are used to close the Reynolds-averaged Navier-Stokes equations,respectively.The large scale separated flow fields and their losses at the stall and post-stall conditions are analyzed for the NREL S809 airfoil at various angles of attack from 0 to 18 degrees.