Numerical investigations of laminar-turbulent transition control in compressible streamwise corner flows

本基础研究的目的是在第一次调查的可压缩，层流流向角流的线性稳定性理论和直接数值模拟的基础上的主动流动控制。当两个平板以直角相交形成平行于自由流流动方向的角或楔时，获得基本构型。这里将研究和比较控制角流中层流-湍流转捩的不同主动方法：全局方法与局部方法，以及抽吸与壁面加热和冷却。这些研究的目的是提高流向角流的临界雷诺数。参考我们以前工作中的最新发现，在风洞实验中观察到的基流变形导致流动的不稳定，在直接数值模拟中观察到的空间瞬态扰动增长，目的是研究是否这两种过程都可以通过角部区域的局部抽吸来稳定。这些调查的目的是稳定的变形边界层的临界雷诺数的未变形和超越，如果可能的话。

The present fundamental research aims at a first-time investigation of active flow control in compressible, laminar streamwise corner flows based on linear stability theory and direct numerical simulations. The basic configuration is obtained when two flat plates meet at a right angle to form a corner or a wedge parallel to the free-stream flow direction. Different active means to control laminar-turbulent transition in the corner flow are to be investigated and compared here: Global versus local methods, as well as suction versus heating and cooling at the walls. These investigations aim at increasing the critical Reynolds number of the streamwise corner flow.In reference to the latest findings in our previous work, where the base-flow deformation observed in wind-tunnel experiments led to a destabilization of the flow, and where spatial transient disturbance growth was observed in direct numerical simulations, it is intended to investigate whether both processes can be stabilized by local suction in the corner region. These investigations aim at stabilization of the deformed boundary layer up to the critical Reynolds number of the undeformed and beyond, if possible.