Non-linear math model of the steering channel in the system for controlling thrust vector of a liquid-propellant rocket engine

The paper contains results of developing a non-linear math model for dynamics of the steering channel in the system for controlling the thrust vector of a liquid propellant engine on a space rocket stage with design incorporating an autonomous one-stage analog electro hydraulic steering actuator with an electro hydraulic amplifier with slider valve plungers underlapping throttling windows. Development of the non-linear math model for the steering channel dynamics was based on: methods of integrated simulation of physical properties of working fluids; iterative methods for calculating parameters of working fluids flow in connecting lines, channels, flow-through elements and valves; a modified Seidel method for solving a system of non-linear algebraic and transcendental equations; results of studies of operating processes for steering actuator constituent elements; a numerical Runge-Kutta method for solving systems of non-linear differential equations of fourth order. The paper provides results of testing the developed math model of the steering channel in the system for controlling the thrust vector of a liquid propellant engine by computing transient responses to several stepwise control inputs.