Design, Construction, and Operation of Liquid Nitrogen Cooled MHD Miniature Ship with No-insulation High Temperature Superconductor Magnet

A feasibility study of a magnetohydrodynamic (MHD) ship using no-insulation (NI) high-temperature superconductor (HTS) magnets made of rare earth barium cobalt oxide (REBCO) tape is presented. Based on the preliminary design, fabrication, and experimental results of a miniature MHD ship with NI HTS magnets in a liquid nitrogen environment (77 K), a scale-up design of a full-size MHD ship with REBCO NI HTS magnets at 20 K is presented. The final velocity of the miniature MHD ship is measured to be 4.0 cm/s, which represents 41.7% of the theoretically calculated velocity. Since the applicability of REBCO NI HTS magnets to MHD propulsion is confirmed, a scale-up design of their application to Yamato-1, the first MHD ship with low-temperature superconductor magnets (LTS), is presented. The operating parameters when the designed magnets are applied are compared with those of Yamato-1. Based on the same geometry, it is demonstrated that the application of NI HTS magnets at 20 K can improve the central magnetic field and propulsive Lorentz force by about 3 times compared to the Yamato-1 operated at 4 K.