绕跨声速三角翼的激波/涡干扰流场数值模拟

 在绕三角翼的跨声速流动中,随着迎角的增加,三角翼上的涡破裂位置会出现突然前移的现象。针对这一与亚声速下不同的流动现象,采用带曲率修正的Spalart-Allmaras(SAR)湍流模型,求解定常雷诺平均Navier-Stokes(RANS)方程,对不同迎角下绕65°后掠尖前缘三角翼的跨声速流动进行数值模拟,并在此基础上,采用基于SAR湍流模型的脱体涡模拟(DES)方法,对由激波干扰导致的前缘涡破裂位置的运动规律进行了初步探讨。模拟结果与试验结果对比表明:SAR湍流模型能准确地模拟出三角翼上的激波系统和旋涡结构,并能准确模拟出由于激波干扰导致的涡破裂位置突然前移的现象。此外,对涡破裂后流场的非定常数值研究发现,支架前端正激波的干扰作用使得涡破裂位置向下游移动比较突然,而向上游移动则相对缓慢。

Numerical Simulation of Shock/Vortex Interaction in Transonic Flow Around a Delta Wing

It is observed that delta wings placed in a transonic flow can experience a sudden upward movement of vortex breakdown location as the angle of attack is increased, which is different from the case with subsonic flows. To investigate this flow phenomenon, transonic flows around a 65° swept leading edge delta wing are numerically simulated by solving Reynolds average Navier-Stokes (RANS) equations coupled with a rotation corrected Spalart-Allmaras (SAR) turbulence model. In addition to steady simulations, calculations using detached eddy simulation (DES) based on the SAR turbulence model in the time accurate flow are performed, in which the normal shock movements on the top surface of the delta wing and the corresponding leading edge vortex breakdown locations are preliminarily studied. A comparison with experimental data shows that the simulations based on the SAR model simulate the shock wave system and vortex structures accurately, and capture the phenomena of sudden upward movement of the vortex breakdown location due to shock wave interaction. Additionally, the unsteady simulation of post-breakdown flow shows that, because of the interaction of the normal shock ahead of the sting tip, the location of vortex breakdown moves downstream abruptly while the upstream movement is relatively slow.