进气道等离子体/磁流体流动控制研究进展

为实现高速飞行器的宽速域飞行,如何保证进气道在非设计状态下的性能至关重要。相比于传统被动控制方式,等离子体/磁流体流动控制技术作为新概念主动流动控制技术,由于其具有结构简单,快速响应,并可根据实际飞行条件进行反馈控制等优势,在国内外上得到了广泛关注。本文介绍了等离子体/磁流体在高超/超声速进气道的主要应用方式与等离子体/磁流体建模方法。当进气道处于超临界状态时,等离子体/磁流体流动控制主要通过热阻塞效应产生虚拟型面,从而将激波系推回至唇口,该技术有望在需要短时间流动控制的高马赫数导弹上走向工程应用;由于等离子体/磁流体激励器与壁面平齐安装,对于高超声速飞行条件,相比于粗糙元其对热防护的要求较低,并且通过超声速风洞实验初步证明了通过高频激励对边界层施加扰动的可行性,需要从稳定性理论的角度对其物理机制进行研究。在后续发展中需要进一步创新等离子体产生技术及激励方式,发展等离子体与流的全耦合计算模型等离子体与流的全耦合计算模型与高效算法 ,为指导工程应用提供依据. 

RESEARCH PROGRESS OF PLASMA/MHD FLOW CONTROL IN INLET

In order to realize wide-speed-range flight of high-speed vehicle, it is of great importance to maintain the performance of inlet at off-design. Compared with traditional passive control methods, plasma and magnetohydrodynaimic(MHD) flow control are novel active flow control methods, and they have attracted extensive attention worldwide, as a result of some advantages, such as simple structure, fast response and feedback control based on actual flight condition, etc. In this paper, the main applications of plasma and MHD in hyper/supersonic inlet and dynamics models are introduced. When the inlets are in supercritical state, the shockwaves can be push back to cowl as a result of the virtual surface produced by plasma and MHD, which is based on the effect of thermal chocking. This technology is expected to applied on the hypersonic missile if only short-time flow control is required. The plasma and MHD actuators can be mounted flush on the wall, so that its requirement for thermal protection is less than that of roughness at hypersonic flight condition. The applications of high-frequency plasma and MHD actuation to produce disturbances in boundary layer have been validated through supersonic wind tunnel experiment, and the physical mechanism can be interpreted from the point of stability theory. The innovative developments of plasma source technology and the way of actuation, as well as coupled model of plasma and fluid dynamics and efficient algorithms are required in future, which can provide guidance for engineering application.