MHD flow in thick-walled pipes of ferromagnetic and non-ferromagnetic material

K. Messadek - L. Bühler - Stieglitz. R.

Forschungszentrum Karlsruhe, Postfach 3640, 76021 Karlsruhe, Germany

Abstract
Theoretical and experimental work has been performed to study the magnetohydrodynamic flow of a liquid metal in circular pipes with thick conducting walls made of non-ferromagnetic and ferromagnetic material. In this latter case curvilinear field lines are observed inside the pipe for applied fields close to the magnetic saturation of the material. In this regime the maximum velocities are near the Hartmann walls, while the velocities near the sides are reduced. The velocity profile approaches classical solutions for non-ferromagnetic pipes if the applied magnetic field is far below or above the saturation value of the wall material. The scaling law of the pressure drop found experimentally confirms that proposed by the theoretical analysis and shows especially that the reduction of pressure drop is proportional to the square of the efficient field in the pipe. Figs 5, Refs 11.