Establishing Full Covering Liquid Metal Film Flows Under Poor Wetting Conditions for Liquid Divertors of Fusion Reactors

Abstract

Investigations on the effects of the wettability on the liquid metal free surface film flow states have been performed by numerical simulations and experiments to establish a film flow which can cover the whole bottom solid surface. The effects of the fluid density, the inlet film thickness, and the width of the bottom surface on the film flow states under poor wetting conditions have been investigated by numerical simulations. The results show that the rivulet flow is easily developed when the inlet film thickness is small. The covering bottom surface of the film flow increases with the increase of the bottom surface width. For the liquid lithium, it is difficult to get a full covering film flow by increasing the bottom surface width and the inlet film thickness. A new method by changing the bottom surface shape to obtain a full covering film flow has been proposed by us. First, an experiment of the Galinstan film flow through a chute with a wavy bottom surface has been done to validate the effective of the proposed method. The experimental results indicate that this method is effective for the Galinstan film flow and the experimental results are consistent with numerical simulation results. Second, numerical simulations have been carried out to get full covering lithium film flows. The results show that a full covering liquid lithium film flow can be obtained by optimizing the dimension of the wavy bottom surface.