用转捩模型预测转捩及确定最佳粗糙带高度

采用SST k-ω二方程湍流模型,附加γ-Reθ转捩模型对不同迎角下的NACA0012翼型绕流进行了转捩预测,计算预测的转捩位置与实验结果符合较好,说明γ-Reθ转捩模型对转捩位置具有较好的预测能力。进一步用模型对带有粗糙带的翼型进行转捩预测,获得了不同雷诺数下刚好激发转捩又不引起过大局部压力扰动和附加阻力的最低粗糙带高度,对固定转捩风洞实验有指导意义。

Prediction of Transition and Optimal Roughness Height Based on Transition Model

This paper numerically predicts the transition and transition location on airfoils and the optimal roughness height needed to trigger transition for the artificial fixed transition on airfoils by using the SST k - w tow- equation turbulence model with additional T - Reθ transition model. The numerical results indicate that the transition location predicted by the method with T -Reθ transition model incorporated is in good agreement with that of the experiments. The transition location predicted by this fourequation model is much closer to the experimental result than the purely conventional two- equation turbulence model. The four- equation model method is also used for predicting the transition of the airfoil with a roughness trip under different Reynolds numbers. The optimal roughness height needed to trigger transition without causing excessive pressure disturbance near the roughness and without bringing extra drag is also simulated numerically. The results might be a guidance for the wind tunnel experiments of artificial fixed transition.