γ-Reθ模式应用于高速边界层转捩的研究

摘要

应用γ-Reθ转捩模式对超声速、高超声速边界层转捩进行数值模拟.γ-Reθ模式通过求解关于当地雷诺数和间歇因子两个输运方程给出转捩起始位置和转捩区长度等信息.本文对马赫数3.5至7范围内的四种算例进行计算,研究了来流雷诺数、攻角变化和头部钝化半径等关键参数的变化对γ-Reθ模式预测流动转捩性能的影响.给出了壁面摩擦阻力系数、热流值与实验值的对比以及壁面附近间歇因子等值线分布等计算结果.γ-Reθ模式能够正确预测攻角和钝化半径变化时转捩位置和流动参数的变化趋势；在较大雷诺数时计算结果与实验值吻合很好.γ-Reθ模式对于超声速或高超声速边界层转捩的模拟仍需修正和改进.%This study evaluates the application of Menter's γ-Reθt transition model with a RANS solver for transition prediction on super-sonic and hypersonic flows.The transition onset position and transition length are approached by utilizing two transport equations for local Reynolds number and intermittency.The present work expands upon the transition prediction methodology by validating the model against wide range of Reynolds number, three-dimensional flows in the form of cones at angle of attack and bluntness effects.Test cases including Mach 3.5 cone with free stream unit Reynolds numbers from 2.8E7 to 7.8E7, Mach 5.91 flared cone and cone with 0 to 4deg angle of attack and Mach 7.16 cone with 3 nose radius have been performed.Comparisons for skin-friction coefficient and heat transfer with experimental data are presented.Results show that this model predicts the correct trends with respect to angle of attack and bluntness effects.It is found that the agreement between simulation and measurements varies better from small Reynolds number to large cases and .However there still are few limits in this very model in predicting supersonic or hypersonic transition process.