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

First experiments with turbulent duct flows of liquid metals exposed to magnetic fields have been performed in the mid-thirties of this century. Results of these experiments in which only the pressure drop along the duct was measured have been interpreted as strong suppression of turbulence leading ultimately to complete laminarization of the flow if the magnetic field becomes strong enough. Only 30 years later, in the mid-sixties, when local turbulence measurements were performed, it became clear that the phenomena under investigation are much more complicated and that not only full laminarization almost never occurs in magnetic fields. In fact intensity of turbulence in many cases increases with the magnetic field. A strong anisotropy (with a tendency for two-dimensionality) of the modified turbulence was discovered and corresponding fundamental changes in the transfer of energy, heat and mass have been predicted. The present paper presents a brief historic review of the investigation of these phenomena and concentrates on results of studies done in the Center for MHD Studies of Ben Gurion University in Israel during the last decade. Main attention is given to the heat transfer enhancement phenomena. However for the analysis of experimental results and for the possibility to make some predictions and assessments beyond the domain of already performed experimental studies it is necessary to present and discuss also results related to velocities fluctuations, energy spectra, etc