Advanced Energy Technology Group
Center for Energy Research
 
 
 
 
 

Thermal Sciences

Magnetohydrodynamics

The interaction of moving conducting fluids with electric and magnetic fields provides for a rich variety of phenomena associated with electro-fluid-mechanical energy conversion. Effects from such an interaction can be observed in liquids, gases, two-phase mixtures, or plasmas. Numerous scientific and technical applications exist, such as heating and flow control in metals processing, power generation from seeded high-temperature gases, magnetic confinement of high-temperature plasmas - even dynamos that create magnetic fields in planetary bodies. Several terms have been applied to the broad field of electromagnetic effects in conducting fluids, such as magneto-fluid-mechanics, magneto-gas-dynamics, and the more common one used here - magnetohydrodynamics, or "MHD".

Practical MHD devices have been in use since the early part of the 20th century; for example, electromagnetic pumping of liquid metals was first described in 1937 by Julian Hartmann [1]. MHD devices also have been used for stirring, levitating, and otherwise controlling flows of liquid metals for metallurgical processing and other applications [2]. Gas-phase MHD is best known in MHD power generation, where, since 1959 [3,4], major efforts have been carried out around the world to develop this technology in order to improve electric conversion efficiency, increase reliability by eliminating moving parts, and reduce emissions from coal and gas plants. Closed-cycle liquid metal MHD systems using both single-phase and two-phase flows also have been explored.

Still more novel applications are in development or on the horizon. For example, recent research has shown the possibility of seawater propulsion using MHD [5] and control of turbulent boundary layers to reduce drag [6]. Extensive worldwide research on magnetic confinement of plasmas has led to attainment of conditions approaching those needed to sustain fusion reactions [7].

MHD studies in the Energy Technology program at UC San Diego are concentrated on solving energy recovery problems for magnetic fusion reactors and on advanced energy conversion systems.

Links:

HYDROMAG International Association for Hydromagnetic Phenomena and Applications


References:

[1] Julian Hartmann, "Theory of the Laminar Flow of an Electrically Conductive Liquid in a Homogeneous Magnetic Field," 1937.

[2] A. F. Kolesnichenko, "Electromagnetic Processes in Liquid Material in the USSR and Eastern European Countries," Iron and Steel Institute of Japan (ISIJ) 30 (1) pp. 8P26, 1990.

[3] P. Sporn and A. Kantrowitz, "Magnetohydrodynamics: Future Power Process?," Power 103 (11), November 1959, pp. 62P65.

[4] L. Steg and G. W. Sutton, "Prospects of MHD Power Generation," Astronautics 5, August 1960, pp. 22P25.

[5] P. Graneau, "Electrodynamic Seawater Jet: An Alternative to the Propeller?," IEEE Transactions of Magnetics 25 (5) pp. 3275-3277, 1989.

[6] A. Tsinober, "MHD Flow Drag Reduction," in Viscous Drag Reduction in Boundary Layers, American Institute of Astronoutics and Aeronautics, 1990.

[7] C. C. Baker, R. W. Conn, F. Najmabadi, and M. S. Tillack, "Status and Prospects for Fusion Energy from Magnetically Confined Plasmas," Energy 23 (7/8) pp. 649-694, 1998.