Research on throat type variable thrust solid rocket motor

Abstract Solid Rocket Motors (SRM) is a power propulsion device using solid propellant, which has obvious advantages in structure, reliability, and ease of use compared with other types of power propulsion devices. With the continuous development of science and technology, the real environment puts forward higher requirements for the maneuverability of rocket engines, and engines with fast start ability and power adjustment functions are becoming more and more important. Therefore, variable thrust solid rocket engines occupy a very important place in the development of future rocket engines. In this paper, the working principle of the throat plug engine is analyzed, and the functional relationship between the thrust and the displacement of the throat plug is derived. The throat bolt solid rocket motor changes the minimum cross-sectional area of the nozzle through the reciprocating motion of the throat bolt on the central axis and then changes the thrust. By establishing a Cartesian coordinate system to describe the shape of the throat plug and the nozzle in the shape of a functional curve, the problem of the minimum cross-sectional area of the nozzle of any throat plug configuration is transformed into the problem of the shortest distance between the two curves, and the established functional relationship between the thrust force and the displacement of the throat plug provides a basis for the design of the throat plug configuration.