Experiments were performed to examine the control effect of surface arc plasma actuators on a fully turbulent boundary layer interaction over a 26-deg ramp in a supersonic flow. The experiments utilized a non-invasive schlieren measurement device, along with comprehensive statistical processing techniques. Time-resolved schlieren up to 25 kHz were performed for visualization. Root Mean Square (RMS), Fast Fourier Transformation (FFT), and Proper Orthogonal Decomposition (POD) were performed on the schlieren dataset for structure identification in the interaction flow. A discharge is created between an electrode pair located upstream of a ramp to induce significant disturbances in the turbulent boundary layer. The discharge frequencies employed are fa=0.5, 1, 2, and 5 kHz. The findings indicate that lower excitation frequencies result in a greater instantaneous energy input to the flow field, while the highest cumulative energy is obtained at 5 kHz over time. The separation region inhibited effect is further verified through the RMS of the schlieren intensity. The separation shock weaken is verified through the FFT of the schlieren intensity. The results indicate that perturbations in the fully turbulent boundary layer interaction flow pattern are more effective for separation shock control and separation region inhibition. It is important to appropriately increase the actuation frequency in order to achieve a certain level of control over the reattachment shock. This control effect is dependent on the total energy injected into the flow field rather than a large energy of a single pulse.

中文翻译：

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由表面电弧等离子体驱动控制的激波和完全湍流边界层相互作用


进行了实验，以检验表面电弧等离子体致动器对超音速流中 26 度斜坡上完全湍流边界层相互作用的控制效果。实验使用了非侵入性纹影测量设备以及全面的统计处理技术。执行高达 25 kHz 的时间分辨纹影以进行可视化。在纹影数据集上执行均方根 （RMS） 、快速傅里叶变换 （FFT） 和正确正交分解 （POD），以识别交互流中的结构。在位于斜坡上游的电极对之间产生放电，以在湍流边界层中引起显著干扰。采用的放电频率为 fa=0.5、1、2 和 5 kHz。研究结果表明，较低的激励频率会导致流场输入的瞬时能量更大，而随着时间的推移，在 5 kHz 处获得最高的累积能量。通过纹影强度的 RMS 进一步验证了分离区抑制效应。分离冲击减弱是通过纹影强度的 FFT 来验证的。结果表明，全湍流边界层相互作用流模式中的扰动对于分离冲击控制和分离区域抑制更有效。适当增加驱动频率以实现对重新连接冲击的一定程度的控制非常重要。这种控制效果取决于注入流场的总能量，而不是单个脉冲的大能量。