转捩模型在翼型气动性能预测 中的应用研究

边界层转捩位置的准确预测对于提高飞行器气动性能的预测精度具有重要意义.选取与k-ω SST湍流模型相耦合的γ-Reθt模型,以零压力梯度平板为研究对象,通过求解基于有限体积法的雷诺平均N-S方程验证该模型自动捕捉流动转捩的准确性;将该模型应用于传统有压力梯度的NACA 0012翼型的流场特性和气动性能的研究中,并与原始k-ω SST模型的计算结果及全湍流试验数据进行比较.结果表明:远场边界距离对翼型阻力系数有较大的影响;与无转捩模型相比,γ-Reθt转捩模型对翼型阻力系数的预测精度有一定程度的提高;对于二维模型,γ-Reθt转捩模型难以捕捉翼型表面的三维效应和非定常分离特性.

Application of transition model in prediction of airfoil aerodynamic characteristics

It is of more significance for improving the prediction accuracy of aircraft aerodynamic performance to predict the transition position of the boundary layer accurately. Selecting the model coupled with SST k-w turbulence model and taking no-pressure-gradient plane as an example, the capability of this model for trapping flow transition automatically was verified. Then the model was applied to study the flow characteristics and aerodynamic performance of NACA 0012 airfoil with pressure gradient, the results from which were compared with the computational result from original SST k-w model and the test data of complete turbulence model. The study shows that the transition position of airfoil surfaces predicted by the model and even the drag coefficients are very good as the angle is less than 12°. While there is a very big deviation as the angle is equal to or bigger than 12°, the reason of which may be that two-dimensional method can not catch three-dimensional effect and unsteady characteristics of separation on airfoil surfaces.