基于动态RCS特征相似的直升机靶机旋翼设计  

Design of helicopter target rotor based on similar dynamic RCS characteristics

作　　者：费钟阳 蒋相闻[1] 招启军[1] FEI Zhongyang;JIANG Xiangwen;ZHAO Qijun(National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics,Nanjing University of Aeronautics andAstronautics,Nanjing210016,China)

机构地区：[1]南京航空航天大学直升机旋翼动力学国家级重点实验室,南京210016

出　　处：《航空学报》2022年第7期145-159,共15页Acta Aeronautica et Astronautica Sinica

基　　金：江苏高校优势学科建设工程资助项目(PAPD)。

摘　　要：为获得具备全尺寸直升机旋翼动态雷达散射截面(RCS)特征的靶机相似性设计方案,首先建立适用于动态旋翼雷达回波信号提取与分析的RCS高频预估方法和时频分析方法。其次,开展了旋翼参数对其RCS时频域谱中的微多普勒特征和信号强度的影响特性研究。然后,推导得到反比形式的旋翼雷达最大微多普勒频移的相似性条件,发现依据相似性条件设计较小半径、较少桨叶片数的靶机旋翼能够模拟出目标旋翼的雷达微多普勒特征,进一步通过改变翼型厚度能够使靶机旋翼具有与目标旋翼接近的RCS信号强度。最后,综合对比不同设计方案的靶机旋翼动态RCS的频域和时域特征,提出模拟目标旋翼雷达散射特性的择优方案:雷达最大微多普勒频移相同、RCS强度相似性误差小于0.408 dB,实现了靶机旋翼对目标旋翼RCS时频特征相似性的设计。This study aims to obtain a helicopter target design scheme with similar rotor dynamic Radar Cross Section(RCS) characteristics of full-scale helicopters. An RCS high-frequency prediction method and a time-frequency analysis method suitable for extraction and analysis of dynamic rotor radar echo signals are firstly established. Then, the effects of the rotor parameters on the micro-Doppler characteristics and amplitude of the rotor RCS are studied, and the similarity conditions for the maximum rotor radar micro-Doppler frequency derived. It is found that by designing the target rotor with a smaller radius and blade number according to the similarity conditions, the maximum radar micro-Doppler frequency characteristics of the target rotor could be similar to those of the goal rotor, and further changes in the airfoil thickness could match the target rotor dynamic RCS time domain signal strength. Finally, the dynamic RCS frequency domain and time domain characteristics of different rotors are comprehensively compared, and the optimal scheme to simulate the radar scattering characteristics of the goal rotor proposed(the maximum radar micro-Doppler frequency being the same, and the error of RCS intensity being less than 0.408 dB) so as to realize the goal of similarity design of the target helicopter rotor RCS time-frequency characteristics.

关 键 词：直升机靶机 旋翼 高频预估方法 时频分析方法 动态RCS 相似性 

分 类 号：V218[航空宇航科学与技术—航空宇航推进理论与工程] TJ02[兵器科学与技术—兵器发射理论与技术]