Computation-and-Experiment Study of Behavior of Molten Metalin Fuel Element and Fuel Assembly: Preliminary Experimentsand Computational Models

This work investigates the motion of the liquid metal on the surface of a heated cylindrical rod. Experiment data are presented, and computational models modified in accordance with the experimental results are described. Exploration of the motion of molten metal over the surface of fuel column simulator both in gravitational runoff and at gas blowoff involved high-speed recording. Formation of rivulets and droplets has been recorded, as well as their separation from the surface at gas blowoff. Based on the experiments to simulate the melt motion, it is proposed to take into account the capillary interaction forces and to consider—in addition to solid, film draining—the rivulet runoff mode. Analysis of literature made it possible to suggest a criterion for the transition from the film mode to the rivulet mode, as well as a method of calculating the basic parameters for the rivulet mode.