近日，印度SRM大学安得拉邦分校的Satya P Jammy及其研究团队取得一项新进展。经过不懈努力，他们揭示斜坡激波边界层相互作用中自由流马赫数变化的侧壁影响。相关研究成果已于2024年8月6日在国际知名学术期刊《理论与应用力学快报》上发表。

本研究探讨了斜坡诱导激波边界层相互作用中，端壁对纵横比为1的三维效应的影响。模拟采用三维自由流马赫数下的展向对称边界条件进行，使用了内部开发的可压缩超声速求解器“OpenSBLIFVM”[1]。本研究采用了两个自由流马赫数，即2.5和3，并将模拟结果与Mangalagiri和Jammy[2]的纵横比为1的模拟结果进行了比较。

入流采用相似性解进行初始化；基于边界层厚度的雷诺数进行了调整，以确保在所有模拟中斜坡起始处的雷诺数保持在3×10⁵。结果显示，与二维模拟相比，侧壁的引入导致中心线分离长度缩短。这与[2]在马赫数为2时的结果相矛盾。Mangalagiri和Jammy[2]在马赫数为2时在中心分离区域观察到的涡旋，在自由流马赫数增加时已消失。

此外，当自由流马赫数从2增加到2.5时，相互作用的拓扑结构从第二类猫头鹰状分离转变为第一类。可以得出结论，与二维相比，相互作用的拓扑结构是中心分离长度增加或减少的关键。

附：英文原文

Title: Sidewall influence of varying free stream Mach number in ramp induced shock wave boundary layer interactions

Author: Raja Mangalagiri, Satya P Jammy

Issue&Volume: 2024-08-06

Abstract: This study investigates the 3D effects introduced by the end walls for an aspect ratio 1 in ramp-induced shock wave boundary layer interactions. The simulations are performed using symmetry boundary condition in spanwise at free-stream Mach num- bers in three dimensions. The simulations are done using an in-house compressible supersonic solver “OpenSBLIFVM”[1]. Two free stream Mach numbers 2.5, and 3 are utilised in the current work, the simulated results are compared with the aspect ratio 1 simulations of Mangalagiri and Jammy [2]. The inflow is initialized with a similarity solution; its Reynolds number based on the boundary layer thickness is adjusted such that the Reynolds number at the starting of the ramp is kept at 3 × 10⁵ for all simu- lations. From the results, it is evident that the introduction of sidewalls resulted in a shorter centerline separation length when compared with the 2D simulations. This is contradictory to the results at Mach 2 by [2]. The vortex observed at Mach 2 by Man- galagiri and Jammy [2], in the central separation region, has vanished with increasing the free-stream Mach number. Also, the topology of interaction has changed from owl- like separation of the second kind to the first kind when the freestream Mach number has increased from 2 to 2.5. It can be concluded that, the topology of interaction is key to the increase or decrease of the central separation length when compared to 2D.

DOI: 10.1016/j.taml.2024.100541

Source: http://taml.cstam.org.cn/article/doi/10.1016/j.taml.2024.100541