Modeling of liquid metal duct and free-surface flows using CFX.

Liquid metal free-surface flows provide an option of a renewable surface for heat absorption, removal of impurities, and eliminating the problems of erosion and thermal stresses [1], [2]. In a tokamak liquid metal flows through a strong magnetic field, which results in a magnetohydrodynamic (MHD) interaction. For a free-surface flow the MHD interaction may be even more important than for the duct flows in blankets, because the electromagnetic forces may significantly deform the free-surface and thus make it unfavorable for heat extraction. The MHD-related problems for the free-surface flows have been reviewed in [3]. Among the most important ones are the effects of nonuniform magnetic fields, inertia, surface tension, wettability and roughness of walls on both the jet/drop shape and trajectory. The main problems for the jet divertor are shown in Figure 1 and Figure 2 [4]. Particular issues related to some of the problems listed in these figures have already been tackled (Problem 1 in [5]-[7], 4 in [8], [9], 5 in [9], 6 in [4], 7 and 10 in [9], 9 in [10]). Once main fundamental aspects for each of these sub-problems are understood, the analysis will have been performed for a particular divertor design.