超声速大迎角分离流中三种湍流模型的比较研究

Comparison of three turbulence models in supersonic high-attack-angle separated flows

通过对雷诺平均N-S方程的数值求解,模拟了细长旋成体在超声速大迎角下的流场,比较了S-A,SST和EASM三种湍流模型。不同轴向位置的物面周向压力分布和实验结果的对比结果表明:湍流模型对物面压力分布影响较大。横截面流态分析表明,空间主体涡结构受湍流模型影响不大,靠近壁面的二次分离涡的模拟精度和湍流模型密切相关。弹体积分气动力受湍流模型影响不大,和实验结果相当吻合。

Three popular turbulence models are compared by simulating the complex supersonic flows around long ogive-cylinder missile. A newly developed flux splitting scheme-AUSM^＋ -up, is adopted to obtain high resolution and robustness. The numerical results show the capability of individual turbulence model in dealing with cross separation and vortices. S-A model under-predict the cross separation and can not capture the subtle secondary vortices correctly. SST model is compared to EASM model in capturing cross separation, however not as clearly as EASM in simulating the secondary vortices. But the integrated aerodynamic forces are similar for three models, and are within ＋ 3 % agreement with experimental data. Higher Mach number can lead to earlier boundary-layer separation along axial location, and larger vortices developing in space.