Yurkov B. Development and justification of the calculating methodology for the storage and feed system of the working substance of an electric propulsion system

Nowadays, electric propulsion systems (EPS) are widely used on board modern spacecraft. The working substance feed system (FS) is an essential part of any electric propulsion system. In this regard, the working substance feed system has a significant impact on the performance, weight and cost of both the EPS and the satellite as a whole. Analyzing modern Ukrainian and foreign sources in this area, it can be concluded that there is no complete methodology that allows to calculate and manufacture a working sample of the feed system. In the course of the work, the following tasks were identified and implemented: a) to analyze existing schemes and justify the choice of the structural scheme of the working substance storage and feed systems, on the basis of which the presented methodology was tested. b) a methodology for calculating the parameters of the tank and the optimal parameters of the working substance in the tank is proposed, which allows to determine the pressure and density of the working substance filling, which can be used to select the tank and determine the remaining working substance during the mission. c) developed a methodology for calculating the main elements of the working substance feed system, such as − mass flow restrictors to obtain the required length of capillary tube to ensure the required mass flow rate of the working substance at a given pressure and temperature; − a new structural element (gasifier) to prevent the liquid phase of the working substance from entering the accumulator tank; − accumulator tank and parameters of the working substance in the accumulator tank. d) substantiated the use of model gas (Ar) instead of xenon for testing flow restrictors and the feed system as a whole, including the derivation of an improved formula for converting the mass flow rate of model gas to the mass flow rate of xenon e) optimized modes of filling the accumulator tank, which allows to maintain the required pressure in the accumulator tank while reducing the estimated volume of the accumulator tank and the number of electric valve actuations. The main results of the PhD thesis are as follows: a) for the first time, a comprehensive methodology for calculating the storage and feed system of working substance for the EPS was created. b) algorithms for maintaining pressure in the accumulator tank for a wide range of pressures in the tank of the working substance storage system are proposed. c) improved methods of calculation of certain elements of the working substance feed system are proposed.