高超声速飞行器尾迹转捩及其对雷达散射截面的影响

Wake Transition of the Hypersonic Vehicle and Its Influence on RCS

当飞行器在大气层中以高超声速飞行时,在下游形成的等离子体尾迹有可能引起雷达散射截面(RCS)突增现象,影响飞行器的探测、跟踪和识别。在自由飞弹道靶上开展高超声速模型流场特性试验研究,测量不同马赫数和靶室压力下模型尾迹的流场结构和转捩位置,利用转捩准则对试验结果进行分析,讨论了转捩位置变化对高超声速飞行器RCS特性产生的影响。结果表明:模型特征尺寸、飞行马赫数和压力等是影响转捩位置的主要参数;尾迹对高超声速飞行器RCS的影响非常复杂,将改变RCS大小,使雷达成像变模糊甚至产生假目标。

A long plasma wake is formed downstream when a hypersonic vehicle is flying in the atmosphere. It may cause a sudden increase in radar cross section( RCS),which affects the detection,tracking and identification of hypersonic vehicle. The flow field characteristics of hypersonic model in the free flight ballistic range is experimentally studied. The flow field structure and transition position of wake at different Mach numbers and chamber pressures were measured. The possible influence of transition position on the RCS characteristics of hypersonic vehicle is discussed. The results show that the model feature size,flight Mach number and chamber pressure are the main parameters affecting the transition position.The influence of the plasma wake on the hypersonic vehicle RCS is very complicated,which changes RCS and makes the radar imaging blurry,and even produce the fake targets.