Research on high-speed electric pump for rapid-start rocket fuel system based on electromechanical co-simulation

High-speed electric pumps are critical equipment for rapidly delivering propellants to kerosene rocket engines. The proposed novel motor design takes advantage of the residual pressure at the turbine end, which eliminates the need for complex dynamic sealing structures and allows the rotor cavity to be fully immersed in kerosene for effective cooling and lubrication of the bearings and rotor. However, this configuration also introduces significant liquid resistance torque during the start-up phase, which hinders the rapid acceleration of the rotor. To accurately predict start-up time while accounting for immersion conditions, this paper investigates the relationship between rotor resistance torque and key physical parameters such as rotational speed, rotor dimensions, and fluid properties in kerosene. An electromechanical co-simulation model is established to capture the coupled dynamics of the electric pump during start-up. Finally, the accuracy of the proposed model is validated through prototype experiments, confirming its suitability for high-speed electric pump design under rocket fuel conditions.