小攻角下翼型边界层分离对数值模拟结果的影响研究

Influence of boundary-layer separation of aerofoil under small angle of attack on the numerical simulation

基于三维RANS方程,分别选用RNG k-ε和RSM(雷诺应力模型)两种湍流模型对NREL S809翼型进行了CFD数值模拟,得到翼型的气动性能,并对比其计算结果。结果表明:随着攻角的增大,翼型边界层会产生分离。翼型边界层分离前,两种湍流模型模拟结果与实验数据有一定误差,但基本一致。翼型边界层分离后,模拟结果与实验数据相差较大,特别是随着攻角增大,流场内湍流运动加剧,模拟结果误差也随之增大。因此,边界层的分离是影响模拟结果的重要因素。

Based on the three-dimensional RANS,a numerical simulation on NREL S809 airfoil was carried out with RNG k-ε and RSM turbulence models,respectively.The airfoil aerodynamic performance was proved and a comparison of the results from the two models was made.The results showed that airfoil boundary layer separates with the increasing angle of attack.Before the separation,the simulation results are basically consistent with the experimental data despite some errors.However,the differences between simulation results and experimental data become much larger after separation.Along with the increase of angle of attack,the turbulent flow is intensified and errors of simulation results also increase.Therefore,it proved that the separation of aerofoil boundary layer is a vital factor which influences the simulation results.