多孔介质、微槽道和超声波吸声材料等可用于抑制高超声速边界层第二模态扰动波.通过声波在无穷长小管道中的传播模型给定多孔介质表面的扰动边界条件,采用时间模式的线性稳定性理论分析了多孔介质表面对边界层稳定性的影响.对马赫数6热壁平板边界层的考察表明,多孔介质表面不仅可以大大推迟第二模态扰动波的中性点,还可以大大抑制最不稳定第二模态扰动波的幅值增长率.为了找到最优控制参数,在较广的参数范围内考察了多孔介质表面的开孔率和孔半径对第二模态扰动波幅值增长率的影响,得到了最优开孔率和孔半径沿流向的分布.最后,还考察了基本流的当地非平行性(法向速度)对控制效果和最优控制参数的影响.%It is reported that micro pores,micro grooves and ultrasonically absorptive surface can be used to suppress second-mode waves in hypersonic boundary layers.In this study,the boundary conditions of porous surfaces are modeled with the theory of acoustic wave propagating within thin and long tubes,and the temporal linear stability theory is used to study the stabilization effect on boundary layer of porous surfaces.The investigation of a Mach 6 hot flat plate boundary layer shows that porous surfaces can delay neutral points as well as suppress the growth rate of the most unstable second-mode waves.In order to find out the optimal porosity and pore radius for stabilizing the boundary layer,we investigate a wide range of parameters.The optimal parameters along the plate surface are discovered.Furthermore,the nonparallel (wallnormal velocity) effect of the base-flow is studied on the optimal parameters and control effect.
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