Interaction between a piston of conducting liquid and a magnetic field

G. G. Kapustyanenko - A. I. Syusyukin - S. S. Pignastii

Abstract
An investigation was made of the interaction of a ring-shaped liquid-metal piston, moving in the channel of a linear cylindrical inductor, with a homogeneous radial magnetic field. Pistontype motion of a portion of liquid metal in a control section of a coaxial channel with a length of 70 cm (with diameters of the annular cross section of 9 and 11 cm) was realized in experiments if the initial length of the piston l_o exceeded its mean diameter D by not more than 1.9 times. It was established that, in the absence of external-load electrical circuits, the values of the current induced in the piston and the resultant magnetic field ahead of the piston in the region of the investigated values of l0/D do not depend on the velocity of the piston, in the range of the values from 16 to 47 m/sec, and are functions of the initial length of the piston, the field of the excitation, and the position of the leading front of the piston in the channel.