Effects of Surface Compliance on Shock Boundary Layer Interaction in the Caltech Mach 4 Ludwieg Tube
Effects of Surface Compliance on Shock Boundary Layer Interaction in the Caltech Mach 4 Ludwieg Tube
复制标题
表面柔度对 Caltech Mach 4 Ludwieg 管中冲击边界层相互作用的影响
DOI：
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
J. Austin
中科院分区：
文献类型：
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作者：
M. Neet;J. Austin
了解由湍流边界层和激波边界层相互作用引起的流体-结构相互作用对薄而柔顺的结构的影响，对于开发轻量化、可重复使用的高速车辆至关重要。在这项工作中，首先在1)刚性平板上研究4马赫边界层中的流动结构，以建立基线；ii)静态变形几何形状，以研究更长时间尺度上表面变形的流动响应。接下来，研究了在振动激波发生器静、动载荷作用下柔性钢板上的流动响应。在加州理工学院4马赫路德维格管试验段进行欧拉模拟，设计激波发生器的几何形状和位置，预测驱动压力波穿过柔顺表面所需的振荡幅度，并计算动载荷引起的柔顺表面压力上升。讨论了影影视频、快速响应压敏涂料型材和激光位移传感器测量0.2 mm厚钢板对冲击发生器加载的响应，并与刚性外壳的类似测量结果进行了比较。在这些条件下，柔性面板中心点变形了近4个面板厚度，导致相互作用位置的分离区域变平和拉长，与刚性面板情况相比，面板表面的静压更低。
Understanding the effects of fluid-structure interactions caused by turbulent boundary layers and shock boundary layer interactions, on thin, compliant, structures is crucial for developing light-weight, reusable, high-speed vehicles. In this work, flow structures in a Mach 4 boundary layer are first studied over i) rigid flat plates to establish a baseline and ii) statically deformed geometries to investigate the flow response to surface deformation over longer time scales. Next, the flow response over a compliant steel panel under static and dynamic loading from an oscillating shock generator is investigated. Euler simulations are performed to design the geometry and location of the shock generator in the Caltech Mach 4 Ludwieg tube test section, predict the amplitude of the oscillation required to drive the pressure wave across the compliant surface, and to calculate the pressure rise on the compliant surface due to the dynamic load. Schlieren video, fast response pressure sensitive paint profiles, and laser displacement sensor measurements of the response of a 0.2 mm thick steel panel to loading from the shock generator are discussed and compared to similar measurements of the rigid case. The compliant panel center point deforms by nearly 4 panel thicknesses under these conditions and results in a flattened and elongated separation region at the interaction location and lower static pressure on the panel surface when compared to the rigid panel case.