Model of active protection element impact on guided missile in calculated space point
The paper describes the process of spatial movement of the aircraft relative to the earth coordinate system by a system of differential equations, taking into account the dynamics and kinematics of translational and rotational motion. The aerodynamic impact of the environment on the aircraft is determined by its configuration, position of the associated coordinate system relative to the velocity of the aircraft center of mass and vector of its angular velocity. To ensure an aircraft steady state flight mode the model solved the problem of balancing, consisting in the engine thrust values, angle of attack and the deviation of the aircraft control organs selection with subsequent solution of the system of differential equations. The output variables of the model are the parameters characterizing the actual position of the aircraft in space. The calculated missile trajectory, represented in the form of differential equations and algebraic dependencies, describes the missile guidance to the aircraft. The result is the relative distance value of the aircraft defined by the elevation angles and azimuth. The rocket direction of motion measurement is made according to the method of proportional guidance. The control system sets the missile maneuver with an overload, directly proportional to the angular velocity of the rocket-target line of sight. Thus, any time it tends to ensure the direction of the missile movement to the set-forward point. Based on the canonical equation of motion of the center of mass of the active protection element the terms of its ejection, to deliver it to the point of space where the guided missile is situated was calculated. By simulating the flow over the active element by turbulent incident flow, using finite volume method in Ansys CFX the authors defined the ballistic coefficient of the active protection element. It allowed us to calculate the resistance function value and produce the data on trajectory and projection parameters of active protection element to the control unit. As a result, this model allows calculating, under different tactical actions of the aircraft crew, the target miss, the orientation angles and missile speed of convergence with the aircraft. When processing simulation results one can obtain the characteristics of the missile encounter with an aircraft, as well as active element ejection parameters for its encounter with the rocket in calculated space point.