用不同湍流模型预测机翼边界层分离区

介绍了机翼气流分离区的预测方法和不同湍流模型对其预测结果的影响。分析了C-S模型用于分离流计算的缺点,提出了对模型的若干种改进方案,并通过实例计算说明它们的应用效果。还给出了使用k方程模型求解边界层分离流问题的技术细节与技巧,对计算结果与代数模型结果以及试验结果作了比较。结果表明,对C-S模型的原型作适当修正是必要的,修正内容包括在外层粘度系数定义时用流向位移厚度来取代三维位移厚度,并计入壁面流线角影响;在定义内层粘度系数时,需计入压力梯度影响和横向与纵向旋涡粘度比的影响。

Prediction of Wing Boundary Layer Separation Area With Turbulent Models

A predicting method of wing turbulent separation area and the influence of different turbulent models on the results of prediction are introduced. The authors analyze the defects of C-S model used in the calculation of separation flow, put forward some improvement schemes and illustrate their application effect through the calculation of concrete examples. Besides, The, technical details and skills for solving the problems about boundary layer separation flow using k-equation model are also given. The calculation results are compared with the algebra model results and the experiment results. The results show that it is necessary to make some improvements on the C-S turbulent model in the original form, including using direction flow displacement thickness to replace 3D displacement thinckness and considering surface flow angle in definition of outer layer viscous coefficient, and the pressure gradient effects and the transverse/ longitudinal viscosities ratio should be considered in definition of the inner layer viscous coefficient.