CHOICE OF GAS-DYNAMIC THRUST VECTOR CONTROL TYPE IN ROCKET ENGINE PROJECT DEVELOPMENTS

One of the important tasks of ensuring controllability for designing rockets is the type and efficiency choice of the executive bod- ies for the thrust vector control of the rocket engine. The efficiency and physical principle analysis of executive control rocket system bodies makes it possible to state that nowadays, there is no universal executive control body applicable to different rocket types. Thus, the choice of control system type may have non-typical, alternative executive bodies or systems. The combined thrust vector control system including mechanical and gas-dynamic subsystems has been developed at the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine. This system has the combined advantages of its component subsystems. In addition, such a system obtains an additional advantage — greater thrust vector control reliability due to subsystem duplication. For such system design, the task of rational type choice of gas-dynamic thrust vector control body inevitably arises. Comparing the characteristics of different gas-dynamic thrust vector control bodies in the rocket engine development project with a combined thrust vector control system and developing recom- mendations for choosing a rational scheme for the used gas-dynamic system becomes an urgent task in engine design. Computational studies of gas-dynamic thrust vector control body characteristics have been carried out. At the same time, a semi-empirical calculation method of various gas-dynamic executive body type efficiency is used, based on ratios describing the supersonic flow disturbance in the rocket engine nozzle by different obstacles: injection, blow-in, solid obstacle on the nozzle wall. The main calculation features of gas-dynamic processes of engine control are shown. Practical recommendations have been developed for the application of gas-dynamic thrust vector control systems, which can be used in the design of various rocket engine types. This allows choosing a rational thrust vector control system and determining its characteristics at the design stage.