應用地磁場與超導體的電磁力推進原理與系統之研發
Development of magnetic propulsion using geomagnetic fields and superconductors and demonstration by an innovative sensor for micro-thrust measurement
Space travel nowadays relies on physical ejection of propellants, which imposes a limit on the reachable distance of a vehicle in reasonable time. In contrast, electromagnetic propulsion was proposed to apply the force interaction between the local magnetic field of the vehicle and the external natural magnetic field specifically the geomagnetic field. This removes the need of carrying bulky materials for creation of physical reaction forces and largely enhances possibility of long-term flight in space. However, the practicability has not been truly envisioned since the thrust that can be generated by the nonuniform geomagnetic field is extremely small. Here we propose an alternative concept of design, based on the variation of local magnetic dipole moment that has not been considered, and demonstrate its feasibility. We computed the force exerted on a solenoid in an applied magnetic field, and compared with the experimental results to verify the effect of magnetic moment gradient on the resulted force. The force was further enlarged when an iron core was inserted. To test, we placed the solenoid in the geomagnetic field and measured the forces corresponding to different gradients due to variation of the cross-sectional area and electric current magnitude. The results indicate a proportionality between the force and these factors, as predicted by the theory. Furthermore, to enhance the electric current with negligible dissipation, we adopt a superconducting solenoid that can take advantage of low temperature in space. With accessible conditions of operation, our results demonstrate feasibility of creating a thrust comparable to that of present electric propulsion such as magnetoplasmadynamic and Hall thrusters which are viewed as the most promising techniques for near-future space travel. By incorporating supplementary means, we provide a breakthrough solution for constructing an efficient thruster with low energy consumption and nearly null propellant for near-Earth transportation and deep-space exploration.
Published in
Heng-Wei Kuo, Kuo-Long Pan*, and Wei-Li Lee, “A propellant-free superconducting solenoid thruster driven by geomagnetic field,” Journal of Advanced Research 28 (SCIE; IF: 6.992/-, Multidisciplinary Science: 9/71), February, 269-275 (2021); available online 10 August 2020. URL: https://doi.org/10.1016/j.jare.2020.07.014
