Analysis and evaluation on RCS characteristics of helicopter considering modulated effect of rotor
-
摘要: 考虑旋翼调制的影响,建立了适合于直升机全机雷达散射截面(RCS)特性计算的“面元-边缘法”.兼顾计算效率和精度,在外形变化剧烈地区域,网格进行加密处理,并保证电磁网格密度和尺度满足雷达波波长大小的比例关系.以桨盘倾倒方式计入桨叶的挥舞和变距运动,采用准静态法模拟旋翼对全机RCS特性的影响.分析了某直升机RCS极化、姿态、频率响应特性,并根据直升机RCS和雷达探测距离关系,提出了4级预警机制和角域范围.研究表明:旋翼转动时全机RCS动态响应具有连续性和对称性,振荡区散射水平强,RCS幅值为-5~12dB ·m2;奇数片桨叶比偶数片桨叶的RCS减缩2~5dB ·m2,且有利于控制直升机RCS包络线和散射峰值的时域响应,增强雷达隐身性能.Abstract: Considering the modulated effect of rotor, a panel-edge method suitable for solving radar cross section (RCS) characteristics of the whole helicopter was developed. In order to improve grid generating quality of large shape changes, the high density grids were generated considering the accuracy and efficiency. Simultaneously, the density and scale of electromagnetic grids need to meet the radar wave length ratio. The blade pitching and flapping motions were included by inclination of disk, and the RCS characteristics of the whole helicopter effected by rotor were simulated by the quasi-static method. Then calculations and simulations on RCS of an helicopter about the polarization, attitude and frequency responses were carried out. According to the relationship between RCS of helicopter and detecting distance of radar, four-stage warning mechanism and angle domains were presented. The results show that the RCS dynamic responses of the whole helicopter is continuous and symmetric considering the rotating rotor, and the oscillation scattering is strong, with the amplitude of RCS between -5 to 12dB ·m2. Compared with even blades, the RCS of odd blades is reduced from 2 to 5dB ·m2, and the RCS envelope and time domain responses of scattering peak are controlled. Finally, the radar stealth performance can be improved.
-
Key words:
- helicopter /
- rotor /
- radar cross section /
- modulation /
- comprehensive analysis /
- physical optics /
- method of equivalent currents
-
[1] Setlur P,Ahmad F,Amin M.Helicopter radar return analysis:estimation and blade number selection[J].Signal Processing,2011,91(6):1409-1424. [2] 汤子跃,王永良.悬停直升机旋翼回波特性分析[J].空军雷达学院学报,2000,14(3):1-4. TANG Ziyao,WANG Yongliang.Study on blades echo of a hovering helicopter[J].Journal of Air Force Radar Academy,2000,14(3):1-4.(in Chinese) [3] 包晓翔,张云飞,杜晓松.通用直升机雷达散射特性及RCS减缩[J].北京航空航天大学学报,2012,39(6):745-750. BAO Xiaoxiang,ZHANG Yunfei,DU Xiaosong.Radar scattering characteristics and RCS reduction of utility helicopter[J].Journal of Beijing University of Aeronautics and Astronautics,2012,39(6):745-750.(in Chinese) [4] Van Bladel J.Electromagnetic fields in the presence of rotating bodies[J].Proceedings of the IEEE,1976,64(3):301-318. [5] Pouliguen P,Lucas L,Muller F,et al.Calculation and analysis of electromagnetic scattering by helicopter rotating blades[J].Antennas and Propagation,2002,50(10):1396-1408. [6] Yoo J H,Kim C H,Chae D Y,et al.A radar target DB construction method using 3D scattering centers[J].Proceedings of Society of Photo-optical Instrumentation Engineers,2011,8180:81800Z.1-81800Z.6. [7] YE Shaobo,XIONG Junjiang.Geometric optimization design system incorporating hybrid GRECO-WM scheme and genetic algorithm [J].Chinese Journal of Aeronautics, 2009,22(6):599-606. [8] 乔倩,许家栋,刘萌萌,等.直升机的 RCS计算[J].航空计算技术,2009,39(3):56-58. QIAO Qian,XU Jiadong,LIU Mengmeng,et al.Calculating radar cross section of helicopter[J].Aeronautical Computing Technique,2009,39(3):56-58.(in Chinese) [9] 蒋相闻,招启军,徐国华.基于面元边缘法的直升机RCS计算和分析[J].南京航空航天大学学报,2011,43(3):424-429. JIANG Xiangwen,ZHAO Qijun,XU Guohua.Calculation and analysis of RCS of helicopter based on panel edge method[J].Journal of Nanjing University of Aeronautics and Astronautics,2011,43(3):424-429.(in Chinese) [10] Knott E F,Tuley M T,Shaeffer J F.Radar cross section[M].2nd ed.Raleigh,US:SciTech Publishing,2004. [11] Knott E F.A progression of high-frequency RCS prediction techniques[J].Proceedings of the IEEE,1985,73(2):252-264. [12] Jenn D C.Radar and laser cross section engineering[M].2nd ed. Reston:American Institute of Aeronautics and Astronautics Press,2005. [13] Knott E F.The relationship between Mitzners ILDC and Michaelis equivalent currents[J].Antennas and Propagation,1985,33(2):112-114. [14] 赫恩.计算机图形学[M].蔡士杰,宋继强,蔡敏,译.北京:电子工业出版社,2010. [15] 李柱贞.雷达散射截面常用计算法[M].北京:目标特性研究编辑部,1981.
点击查看大图
计量
- 文章访问数: 1252
- HTML浏览量: 1
- PDF量: 962
- 被引次数: 0