How the MHD (Plasma) propulsion works

The MHD (Magnetohydrodynamic, or Plasma) propulsion employs a very simple construction with minimal moving parts. The only moving parts are less than 20 valves needed to occasionally control auxiliary power compressor, or the flow of cold gas to the engine jacket.

The propulsion is used solely on the Vandal project aircraft. The gas is usually xenon. The liquefied gas flows under its own expansion-generated pressure through the chamber jacket, where it undergoes heating and further expansion, and enters the electric ionizer, whose function is very similar to the conventional fluorescent light. The ionized gas is then split into symmetrical injectors and fed into the chamber head (the bulbous cavity). There the gas is ionized further by the X-ray ionizer into a complete plasma state.

The extremely large AC voltage gradient of specific field characteristics and frequency is continuously applied between the chamber head and the chamber nozzle, and this results in simultaneously pinching and pumping the plasma into an extremely narrow, tubular flow path. The Electromagnetic ionizer conditions the plasma, pinching and accelerating it further, imparting speeds over 3-4 Mach.

The aircraft's power is generated by channeling of some of the jacket-heated gas into a turbogenerator, and returning the gas into the injector feeds. During the cold starts the aircraft uses a dedicated storage battery to power the ionizers. Hot start is possible after the chamber standby, wherein the chamber has not received gas flow, is flooded with cooler gas and the electric ionizer is at low power.

The plasma generation characteristics of the engine dictate that speeds below 300-400 are unsustainable. There is a moderate difference between fuel usage at cruise or maximum speed. In order to maintain low speed, only one chamber is used, and the remaining chambers ( 1, 2 of 3 in Vandal T-22, 3 of 4 in Vandal XB-70) are shut down, or put into a standby state.

More specific details are never disclosed by the DOD and Koborg Turbomotors Propulsion Research Center in Kingstad. The Koborg Corporation and the MHD engine are the creations of King Yarl.