基于DES方法的高超声速激波/边界层干扰的双微楔控制数值研究

高超声速飞行器在流场中通常会伴随激波/边界层干扰(SWBLI),其引发的流动分离将导致进气道性能下降。采用湍流离散涡模拟(DES)方法、结合有限体积离散方法与自适应网格加密(AMR)技术对来流马赫数为7.0的流场中SWBLI诱导的流动分离进行数值模拟,并分别采用单、双微楔对其进行控制。针对流场结构、近壁面流向速度、压力梯度及总压损失等参数,分析讨论了不同双微楔流向安装位置对SWBLI的控制效果。研究结果表明:双微楔产生的流向涡对与涡对之间的相互诱导促进了各自流向涡对之间的卷吸作用,使得双微楔对分离气泡的消除效果优于单只微楔;流动总压损失系数随着微楔后缘与分离气泡中心的距离的减小呈先减小后增加的趋势;综合讨论流向涡强度与形状阻力的影响,得到了双微楔最佳流向安装位置。

DES numerical study of shock wave/boundary layer interactions in hypersonic flows controlled by double micro-ramps

Shock wave/boundary layer interaction (SWBLI) is a ubiquitous phenomenon encountered in hypersonic flow field, which can induce flow separation and lead to performance degradation of hypersonic inlet. Detached-eddy simulation (DES) and finite volume method have been used with the adaptive mesh refinement (AMR) technology to simulate the flow separation induced by SWBLIs in hypersonic flow at Ma_∞=7.0, which have been respectively controlled by single and double micro-ramps. The control effects of micro-ramps with different streamwise installation positions on flow separation have been discussed based on the flow structure, near-wall streamwise velocity, pressure gradient and total pressure loss. The numerical results show that the reciprocal induction among the vortices pairs generated by these two micro-ramps shows the promoting effects on vortices entrainment generated by each micro-ramp, consequently the performance of double micro-ramps in eliminating the separation bubble is better than the single. As the distance between micro-ramp the trailing edge and the center of separation bubble decreases, the total pressure loss shows a trend of first decrease and then increase. Discussing the effects of both streamwise vortex intensity and its additional resistance synthetically, the optimal streamwise installation position of double micro-ramps is obtained.