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建立了航空拖曳诱饵系统的物理数学模型,并对诱饵释放过程中,系统的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,以使模型更加完整。对诱饵释放过程中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,载机飞行马赫数越大,缆绳下沉量越小,因此,应控制释放过程中载机最大飞行速度,以避免缆绳进入载机的高温尾喷流区。为避免出现“鱼钩”现象,应尽量减小诱饵的释放初速度与载机空速方向的夹角。按梯形速度释放诱饵时,缆绳中拉力的最大值比匀速释放诱饵时要小,且诱饵的俯仰角变化没有匀速释放时剧烈,因此建议以梯形速度释放诱饵。
The physical mathematic model of air towed bait system is established, and the dynamic characteristics of the system are simulated during the process of decoy releasing. By using the method of mass concentration, the flexible towing cable is discretized into a series of nodes connected by damping springs, and the dynamic model of the cable is established. For the force analysis of the decoy, a six-degree-of-freedom model of the decoy is established. The coupling between the cable and the decoy is proposed Conditions to make the model more complete. The dynamic characteristics of the system during the release process of the decoy are simulated and the variation rules of the shape, tension and attitude angle of the bait are given and analyzed. The results show that the larger the Mach-number of the carrier flight, the smaller the amount of cable subsidence. Therefore, the maximum flight speed of the carrier should be controlled in order to avoid the cable entering the high-temperature tail jet flow area of the carrier. In order to avoid the phenomenon of “fish hook”, the angle between the initial release speed of bait and the direction of airspeed should be minimized. When the bait is released at a trapezoidal speed, the maximum pulling force in the rope is smaller than when the bait is released at a constant speed, and the change in the pitch angle of the bait is severe when the bait is released without a constant speed. Therefore, it is advisable to release the bait at a trapezoidal speed.