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采用计算流体力学方法对降雨条件下翼型的气动特性进行了研究.通过求解定常可压的Navier-Stokes方程来计算流场,采用拉格朗日法对流场中的雨滴轨迹进行了模拟跟踪,得到了翼型表面的雨滴收集率;建立了水膜层数学模型,并假定水膜层沿着翼型表面的法向方向增长,预测了降雨引起的翼型外形的变化,并得到了水膜层表面的粗糙度高度;采用k-ωSST(shear-stress transport)两方程湍流模型结合增强的壁面函数,研究了降雨对翼型气动特性的影响.结果表明,在低迎角范围内,降雨对翼型的升力系数和阻力系数影响很小;当达到失速迎角后,降雨会引起上翼面边界层气流的提前分离,造成翼型气动性能的严重损失.
The aerodynamic characteristics of the airfoil subjected to rainfall are studied by means of Computational Fluid Dynamics (CFD). The flow field is calculated by solving the Navier-Stokes equations with constant pressure and pressure, and the raindrop trajectory in the flow field is simulated by Lagrange method , The collection rate of raindrops on the surface of the airfoil was obtained. The mathematical model of the water film was established, and assuming that the water film layer grew along the normal direction of the airfoil surface, the change of airfoil shape caused by rainfall was predicted and the water The roughness of the surface of the film was measured.The influence of rainfall on the aerodynamic characteristics of the airfoil was studied by using two-equation k-ωSST (turbulence-shear stress) turbulence model combined with the enhanced wall function.The results show that in the low angle-of-attack range, The lift coefficient and drag coefficient of the airfoil have little influence on the airfoil. When reaching the stalling angle of attack, the rainfall will lead to the premature separation of the airflow on the upper airfoil, resulting in serious loss of airfoil aerodynamic performance.