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Title: Aspects of magnetohydrodynamic duct flow at high magnetic Reynolds number
Author: Turner, Roger Bryson
ISNI:       0000 0001 3539 5135
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 1973
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In this thesis we attempt to predict the performance of a device, known as a flow coupler, which consists of an M.H.D. generator coupled to an M.H.D. pump so that one stream of fluid is induced to move by the motion of another. The change of magnetic field experienced by a moving conductor as it passes into an M.H.D. device can cause large eddy currents to circulate within the M.H.D. duct. We have used apparatus in which we represent the moving stream of liquid by an annular disc of aluminium, to investigate the perturbation of the applied magnetic field and of the electric potential distribution caused by these eddy currents. We then examine both experimentally and theoretically, devices in which large currents flow through a moving conductor and through an external circuit. These currents are injected into the moving conductor through electrodes which have a high resistance to currents in the direction of motion. We show that for compensated devices, that is, devices in which the external conductors are arranged so that they produce no transverse magnetic field, the perturbed magnetic field does not depend upon the current through the external circuit and is the same field that would exist if there were no contact between the moving metal and the external circuit. We observe experimentally that when two conductors move side by side through the gap of a magnet the magnetic field in one moving conductor is little affected by the motion of the other. We compare the measured performance of a simulated M.H.D. generator and of a real M.H.D. pump with their computed performances and we calculate the expected performance of a flow coupler. We suggest that the presence of a slowly moving liquid in the boundary layers adjacent to the duct walls may adversely affect the performance of a flow coupler and we conclude that an efficient flow coupler would require non-conducting duct walls and a high magnetic field.
Supervisor: Not available Sponsor: United Kingdom Atomic Energy Authority
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: TK Electrical engineering. Electronics Nuclear engineering