Magnetohydrodynamic Propulsion Apparatus (U.S. Patent 3,322,374)

This document is U.S. Patent No. 3,322,374, issued on May 30, 1967, to James F. King, Jr., for a 'Magnetohydrodynamic Propulsion Apparatus.' The patent details a design for a heavier-than-air craft that utilizes magnetohydrodynamic (MHD) effects for propulsion and control. The core concept involves creating a surrounding ionized air or plasma field around the craft, which acts as an electrically conductive medium. The craft is equipped with a series of polyphase driving coils or rings arranged along its central axis. By applying polyphase alternating current to these coils, the craft generates a moving magnetic field of varying intensity. This traveling magnetic field induces eddy currents within the surrounding plasma, which, according to Lenz's law, interact with the magnetic field to produce a reaction thrust that propels the craft. The patent describes the use of an ionizer ring at the top of the craft to ensure the surrounding air is sufficiently ionized to serve as a conductor. It also incorporates a frusto-conical air-directing skirt to manage the ionized air flow and provide stability, similar to the dihedral effect in conventional aircraft. The inventor suggests that the driving rings could be constructed of superconductive material to increase efficiency and that capacitance could be added to the circuit to maintain resonance. The document includes detailed diagrams illustrating the craft's configuration, the arrangement of the driving rings, and the vector forces involved in its operation. It also outlines methods for directional control, such as varying the ionization in different quadrants or using closed-loop control coils in the skirt to shade the magnetic field. The patent references several prior art documents, including patents by T. T. Brown and others, distinguishing the present invention by its use of a moving polyphase magnetic field rather than stationary D.C. fields.