Dynamic simulation of aerial towed decoy system based on tension recurrence algorithm

Dynamic model of aerial towed decoy system is established and simulations are performed to research the dynamic characteristics of the system. Firstly, Kinetic equations based on spinor are built, where the cable is discretized into a number of rigid segments while the decoy is modeled as a rigid body hinged on the cable. Then tension recurrence algorithm is developed to improve computational efficiency, which makes it possible to predict the dynamic response of aerial towed decoy system rapidly and accurately. Subsequently, the efficiency and validity of this algorithm are verified by comparison with Kane's function and further validated by wind tunnel tests. Simulation results indicate that the distance between the towing point and the decoy's center of gravity is suggested to be 5%-20% of the length of decoy body to ensure the stability of system. In up-risen maneuver process, the value of angular velocity is recommended to be less than 0.10 rad/s to protect the cable from the aircraft exhaust jet. During the turning movement of aircraft, the cable's extent of stretching outwards is proportional to the aircraft's angular velocity. Meanwhile, the decoy, aircraft and missile form a triangle, which promotes the decoy's performance.