航空拖曳诱饵系统的动态特性研究

为准确预测航空拖曳诱饵系统能否干扰成功，建立了系统的物理数学模型并对其动态特性进行了仿真研究。应用集中质量法，将柔性拖曳缆绳离散为一系列由阻尼弹簧连接的节点，建立了缆绳的动态模型；对诱饵进行受力分析，建立了诱饵的六自由度模型；提出了缆绳与诱饵的耦合条件，使模型更加精确。分别对诱饵释放过程中，以及释放完成后载机机动时系统的动态特性进行了仿真研究，给出并分析了缆绳的形状、张力和诱饵的姿态角等参数的变化规律。结果表明：为避免出现“鱼钩”现象，应尽可能减小释放诱饵的初速度与载机空速的夹角；应按梯形速度释放诱饵，以使缆绳中拉力的最大值较小。释放完成后，应控制载机最大飞行速度，以避免缆绳进入载机的高温尾喷流区；载机作盘旋时，缆绳在载机的圆形轨迹之外，且载机飞行速率一定时，角速度越大，缆绳向外趋势越大，越有利于避开载机的尾喷流区。

Study of Dynamic Characteristics of Aeronautic Towed Decoy System

To predict whether the aeronautic towed decoy system can disturb successfully or not, a mathematical-physical model of the system is built and its dynamic characteristics are studied. The lumped-mass method is applied to building the dynamic model of the cable, which disperses as a series of nodes connected by damping springs. Forces of the decoy are analyzed and its model of six degrees of freedom is established. Conditions in which the cable and the decoy are coupled are considered in order to make the model more accurate. The dynamic characteristics are simulated during the decoy release and the aircraft maneuver, respectively. The shape and tension of the cable and attitude angles of the decoy are given and analyzed. The results show that to avoid the phenomenon of "fish hook", the release direction should be almost parallel to the aircraft airspeed. The release rate of the decoy should be trapezoidal to reduce the maximum tension in the cable. The maximum airspeed of the aircraft should be controlled after completing release to avoid the cable entering the exhaust jet of the aircraft. The cable is outside the circular trajectory of the circling aircraft. The greater angular velocity of the aircraft with constant speed is, the greater outward trend of the cable is, which is beneficial to avoiding the aircraft exhaust jet.