摘要
超高速目标再入大气层或在临近空间飞行时,空气电离形成的等离子体鞘对超高速目标的雷达散射特性产生很大的影响.为了研究影响规律,采用并行时域有限差分方法(Finite-Difference Time-Domain,FDTD)计算和分析了超高速目标及其绕流场的雷达散射截面(Rodar Cross Section,RCS).将计算结果和中国空气动力研究与发展中心气动物理靶试验测量结果进行了对比,并模拟了典型飞行状态下绕流场对实际再入超高速目标RCS的影响.由分析结果可知:FDTD数值模拟结果和气动物理靶试验测量结果一致,雷达入射角小角度偏离对RCS会产生明显影响;在典型飞行状态下绕流场对实际再入超高速目标RCS的影响与入射波频率、角度以及雷达制式等有关.在有些角度,等离子体流场可以显著地减小飞行器的RCS.
Scattering of radio waves by hypervelocity object is significantly changed by the formation of ionized shock layer when it reentries the atmosphere or is flying in the near space. To study this question, the radar scattering of hypervelocity object and its flow field is simulated by parallel finite-difference time-domain（FDTD） method. The simulating results are compared with the experimental results which are measured by the radars of aero-physics range in China Aerodynamics Research Development Center. Then the method is used to simulate the effect of plasma flow on the radar cross section（RCS） of a hypervelocity blunt cone under given flow situation. The results show that the simulating results are consistent with experimental results. The radar cross section（RCS） of blunt cone is affected by frequency, incident angle, radar polarization, and so on. In some special radar incident angles, the RCS of blunt cone is decreased by the flow field.
出处
《电波科学学报》
EI
CSCD
北大核心
2013年第6期1076-1081,共6页
Chinese Journal of Radio Science
基金
国家自然科学基金资助项目(109020120
11272336)
973项目(2014CB340200)
关键词
超高速
流场
时域有限差分
雷达
散射
hypervelocity
flow field
finite difference time domain （FDTD）
radar
Scattering
