Thrust measurement methods for electric propulsion based on flexible beam structure

[Background] Electric propulsion systems, compared to traditional chemical propulsion, offer longer operational lifespans and lower fuel consumption in space missions, garnering significant attention in recent years. However, for high-power Hall effect electric thrusters developed based on controlled fusion concepts, measuring thrust proves challenging due to the high-temperature environments required for ionizing propellants in electric thruster, resulting in the generation of hot plasma plumes during operation. As a result, traditional thrust measurement methods are unable to accurately measure the thrust. [Purpose] This study aims to accurately measure thrust during ground testing of electric thrusters for precise control of the spacecraft's attitude and orbit maintenance. [Methods] Firstly, a thrust measurement platform based on flexible beam structure was designed and implemented with capability of measuring the thrust generated by electric thrusters in high-temperature. Simultaneously, a calibration system was built to verify the stability and repeatability of the thrust measurement results. Then, simulation analysis was conducted on the structural mechanics and thermal coupling field of the thrust measurement system under different operating conditions. Finally, the variable specific impulse magnetoplasma rocket (VASIMR) was taken for experimental thrust measurement of its electric propulsion system. [Results] The experimental results of VASIMR indicate the thrust is 266.5 mN measured in real time at the central magnetic field intensity of 0.2 T with a mass flow rate of 20 mg∙s−1. [Conclusions] The thrust measurement platform based on the bending beam structure can meet the measurement requirements of VASIMR, providing valuable references for subsequent experiments. © 2024 Science Press. All rights reserved.