END EFFECTS IN MAGNETOHYDRODYNAMIC CHANNEL FLOW. Research Note 135

Technical Report · Mon Jun 01 04:00:00 EDT 1959

OSTI ID:4219876

Fishman, F

Some effects associated with the termination of electrodes and magnetic field in an otherwise uniform magnetohydrodynamic channel flow are investigated theoretically. The assumption is made that the magnetic Reynolds number based on the channel height and the interaction parameter (the product of the magnetic Reynolds number with the ratio of magnetic to gas dynamic pressure) are both small, so that the induced magnetic field is negligible and the gas velocity and conductivity are uniform everywhere. Significant exchange of energy may obtain under these conditions in long channels. Because of the end effects, the electrodes may carry more, or less, current than the same length of electrode in the middle of a long channel; this leads to the definition of a length representing the end correction for current. Similarly a difference in the total force on the working fluid leads to a length representing the end correction for force. These lengths are calculated for various geometries. The electrical efficiency of a channel acting as a generator is computed for these same conditions. It is shown that the end effects decrease generator efficiency least if the magnetic field extends at least one-half a channel height beyond the end of the electrodes (for generand if the electrodes are not less than 1% of the channel height long, they have an effective length ior current about 0.4 channel heights greater than their actual length. (auth)

• Research Organization: Avco Corp. Avco-Everett Research Lab., Everett, Mass.
• NSA Number: NSA-14-004032
• OSTI ID: 4219876
• Report Number(s): AFBMD-TN-59-5
• Country of Publication: United States
• Language: English

Related Subjects

CONFIGURATION
CURRENTS
EFFICIENCY
ELECTRIC CONDUCTIVITY
ELECTRODES
ENERGY
FLUID FLOW
FLUIDS
GENERATORS
INDUCTION
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
PHYSICS
PRESSURE
REYNOLDS NUMBER
TURBULENCE
VELOCITY