An oblique shock train generally forms an asymmetric structure in a Mach-2.7 flow field within a duct. To study the flow structure and interaction between oblique shock trains and upstream shocks, a ramp with equal width was installed inside a Mach-2.7 straight duct to generate an incident shock and an oblique shock train interaction. A Schlieren system, transient pressure measurements and particle image velocimetry were used to capture quantitative and qualitative shock structure information. Results show that the asymmetric separation deflection of the oblique shock train occurs randomly in the symmetrical straight duct. The separation deflection of the oblique shock train was steady with upstream shock interactions. Under backpressure conditions, the rate of movement of the oblique shock train increases rapidly when it passes through the separation regions generated by the ramp, and the deflection direction of the asymmetric separation may switch. Based on the characteristics of the oblique shock train and upstream shock interaction, a flow control method was used to generate asymmetric upstream flow conditions, providing active control of the oblique shock train deflection direction.

中文翻译：

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斜激波系统的不对称性与流动控制

斜激波列通常在管道内的马赫数 2.7 流场中形成不对称结构。为了研究斜激波串与上游激波之间的流动结构和相互作用，在马赫数 2.7 的直管道内安装了等宽的坡道，以产生入射激波和斜激波串相互作用。纹影系统、瞬态压力测量和粒子图像测速用于捕获定量和定性的冲击结构信息。结果表明，斜激波列的不对称分离偏转在对称直波道中随机发生。斜激波序列的分离偏转与上游激波相互作用是稳定的。在背压条件下，斜激波列通过斜坡产生的分离区域时，其运动速率迅速增加，并且不对称分离的偏转方向可能会发生切换。根据斜激波串与上游激波相互作用的特点，采用流动控制方法产生不对称的上游流动条件，实现对斜激波串偏转方向的主动控制。