Research on the cooling structure and electromagnetic coupling mechanism of electric rocket pump drive system

The rocket electric pump drive system mainly undertakes the function of pressing liquid fuel and oxidizer into the combustion chamber, which puts forward the requirements of low-temperature resistance, high power density and short-time high-speed operation for the electric pump, and at the same time leads to large motor loss and temperature rise. Therefore, in this background, this paper proposes to adopt a Y-shaped runner structure in the stator slot of the motor and introduce cryogenic medium liquid oxygen at a certain flow rate to study the coupling mechanism between the motor and cryogenic medium liquid oxygen. Firstly, the three-dimensional electromagnetic field simulation model of the motor is established, and the electromagnetic parameters and performance of the motor are simulated to find out the loss density, in which the contradiction between the small phase transition temperature region of the cryogenic medium and the large transient winding copper loss needs to be solved. At the same time, based on heat transfer and Newton’s law of cooling to derive the thermal conductivity of the motor and the influence of the runner structure on the motor temperature rise factors. Then the temperature field simulation model of the motor is established, and the temperature distribution law of the motor and the temperature rise under different runner structures are simulated. In the case of the theoretical derivation and finite element simulation results are consistent, the winding temperature rise experiments were carried out, and the results of the study provide a new scheme and optimization direction for the design of the runner in the motor slot.