微型三角楔超声速绕流特性的研究

INVESTIGATIONS ON THE FLOW CHARACTERISTICS OF SUPERSONIC FLOW PAST A MICRO-RAMP

基于大涡模拟(LES)方法,结合WENO格式与自适应网格加密(AMR)技术及沉浸边界法(IBM),对来流马赫数为Ma=2.5条件下的平板上微型三角楔绕流流场进行了数值模拟。数值模拟表明微型三角楔涡流发生器可以显著改变超声速流体边界层结构。计算结果清晰地显示了三角楔上游分离区的流场结构和下游各涡的流态,同时计算表明,微楔对边界层控制过程中,其下游的流向涡对与涡环结构都起了重要作用,并对其作用过程进行了讨论。数值计算与相关实验结果相符,且提供了流场的重要细节,揭示了微楔的控制机理,可为超声速边界层控制研究提供重要支持。

Based on the large eddy simulation,combined with WENO scheme,the adaptive mesh refinement（AMR） technique and immersed boundary method（IBM）,the supersonic flow（Ma=2.5） past a micro-ramp has been simulated.Our numerical results reveal that the wall-mounted micro-ramp can modify the flow structure of a boundary layer obviously.The detail flow structures and the vortex evolution around the separation region and the wake have also been visualized clearly.Meanwhile,it also indicates that the streamwise vortices and the vortex rings downstream the micro-ramp have the same important effects in controlling of the boundary layer separation,and that the interactions among themselves have been discussed.Our calculated results are in a good agreement with corresponding experimental data,provide an important detail for flow structures,and reveal the mechanism of boundary layer control,which can provide an important guidance for the related research.