PRESENT UNDERSTANDING OF MHD AND HEAT-TRANSFER PHENOMENA FOR LIQUID-METAL BLANKETS

A review of experimental work on magnetohydrodynamic (MHD) and heat tr ansfer (HT) characteristics of liquid metal flows in fusion relevant c onditions is presented. Experimental data on MHD flow pressure drop in straight channels of round and rectangular cross-section with electro conducting walls in a transverse magnetic field show good agreement wi th theoretical predictions, and simple engineering formulas are confir med. Less data are available on velocity distribution and HT character istics, and even less data are available for channels with electroinsu lating walls or artificially made self-healing electroinsulating coati ngs. Some experiments show an interesting phenomena of HT increase in the presence of a transverse or axial magnetic field. For channels of complex geometry - expansions, contractions, bends, and manifolds - fe w experimental data are available. Future efforts should be directed t oward investigation of MHD/HT in straight channels with perfect and no nperfect electroinsulated walls, including walls with controlled imper fections, and in channels of complex geometry. International cooperati on in manufacturing and operating experimental facilities with magneti c fields at, or even higher than, 5-7 T with comparatively large volum es may be of great help.