Design of a ten megawatt rocket driven disk MHD generator

Abstract

A ten megawatt rocket driven MHD disk generator system has been designed as part of the feasibility study of multimegawatt MHD space power systems for SDI0 mission applications. The experimental system consists of a plasma generatodinjector, a supersonic nozzle, a parallel wall disk channel, and a diffuser. The magnetic field is provided by a heat sink cryogenic magnet coil. Facility support systems include a reactant feed system, a cooling system, an excitation and power extraction system, an exhaust system, and the required instrumentation and control system.The fuel is an aluminum-MMH gel. The oxidizer is a potassium nitrate-IRFNA solution. At the design oneto-one mixture ratio, the specific enthalpy is 10 MJkg. The products of combustion are expanded from the stagnation combustion pressure of 11 atmospheres to supersonic/ sub-atmospheric flow conditions at the inlet of the channel. The supersonic nozzle consists of 24 water cooled vanes which impart a 45 degree swirl to the working fluid at the entrance of the MHD channel. The MHD channel operates in the impulse mode with a nearly constant plasma conductivity in the range 40 to 50 mho/m from the channel inlet to its exit. The magnetic induction is tapered from an inlet value of 5 Tesla to an exit value of 3.25 Tesla. For atmospheric pressure exhaust and a diffuser recovery of 50 percent, an enthalpy extraction of 1 MJkg is predicted so that at the design flow rate of 10 kg/sec, a power output of 10 MW is projected. Following initial excitation, power for the magnet is provided by the channel itself. Fabrication of the system components was initiated early in 1989. Testing is planned for the second half of 1989.

Computation of Transient Radiative Reactive Thermosolutal Magnetohydrodynamic Convection in Inclined MHD Hall Generator Flow With Dissipation and Cross Diffusion

“…These exploit magnetohydrodynamics to generate sustainable, clean, durable power generation and can be deployed in many branches of technology as reviewed by Messerle [1]. MHD generators frequently employ hightemperature working fluids (plasma, gases, superheated sea-water etc) and can substantially enhance conventional thermal power generating system efficiency from 40% to above 70% since they recycle a lot of the heat which otherwise in conventional systems would be rejected MHD propulsion for surface vessels [2], coal-fired combustion enhancement [3], hybrid solar-MHD astronautical power systems [4], driven disk MHD rocket propulsion [5], fusion Rankine bypass cycles [6], nuclear submarine electromagnetic drives [7] (wherein silent operation at much higher speeds is achievable with MHD propulsion systems without encountering cavitation and high turbine blade losses associated with ordinary propellers), commercial ship propulsion [8,9] and MHD wave energy generation designs [10]. Magnetohydrodynamic (MHD) propulsion and power generation systems function with different physical principles than do conventional propeller drives and industrial energy generators and are therefore not subject to the same physical limits.…”

Project New Orion: Pulsed Nuclear Space Propulsion Using Photofission Activated by Ultra-Intense Laser

“…The first stage launch vehicle to the proposed Project New Orion application has two operational capabilities: providing a preliminary velocity increment and providing an energy source to operate the ultra-intense laser. A magneto-hydrodynamic generator can provide an appropriate energy source by converting a portion the thermal/kinetic energy of the rocket thrust to electrical energy [16]- [18]. Magneto-hydrodynamic generator incorporates a strong magnetic field interacting with plasma, such as the propulsive flow of a rocket accelerating through an isentropic expanding diverging rocket nozzle, positioned between two conducting electrodes.…”

“…Magneto-hydrodynamic generator incorporates a strong magnetic field interacting with plasma, such as the propulsive flow of a rocket accelerating through an isentropic expanding diverging rocket nozzle, positioned between two conducting electrodes. This configuration results in the generation of an electric current with an associated voltage potential difference between the electrodes [16]- [18]. Because of the common features between a magneto-hydrodynamic generator and rocket propulsion system, such as high kinetic energy plasma rocket exhaust and cryogenic cooling for a superconducting magnet, magneto-hydrodynamic generators have been proposed as a electrical energy conversion system for rocket propulsion applications [17] [18].…”

“…Solbes et al applied a cryogenic magnet cooled by liquid nitrogen enabling a 5T magnetic field about the inlet channel. With a 95% combustion efficiency producing a thermal power of 95MW, the magneto-hydrodynamic generator produces 10MW of extracted electrical power [18]. Based on the feasibility study published by Solbes et al the electric energy conversion efficiency of the magneto-hydrodynamic generator will be conservatively scaled to 10% of the rocket propulsion thrust power.…”

Open-cycle multi-megawatt MHD space nuclear power facility

“…The development of up to 1000 MW(e) MHD generators based on chemical fuel with pulsed (up to 10 sec) and short-time (100-1000 sec) action does not present any great difficulties [12][13][14]. Ground-based prototypes of such MHD generators already reach power levels up to 500 MW(e) with specific "dry" mass up to 0.1 ton/MW, energy conversion coefficient up to 15%, and power density up to 600 MW/m 3 .…”