Use of turbulence modification for heat transfer enhancement in liquid metal blankets

Heat transfer intensification in the process of liquid metal flow in a magnetic field represents a rather important problem in connection with fusion reactors. In this paper we present a review of experimental investigations carried out in this direction during the last decade at the Centre for MHD Studies of Ben-Gurion University. We have studied the influence of the transverse magnetic field on turbulence in mercury flow with various turbulizers. In certain cases a jump-wise growth in fluctuation intensity with magnetic field is observed. This leads to the enhancement of heat transfer from the wall. Recently heat diffusion processes in two-dimensional turbulent flows have been studied in experiments with thin (0.5 mm) heated grids. A considerable increase in velocity fluctuation intensity is observed behind such grids in the low temperature portion of the spectrum. Here the type of temperature fluctuation spectrum depends on the magnetic field value. The temperature fluctuation intensity decreases in fields of the order of 0.5 T, while a further field increase leads to its enhancement.