Large-eddy simulation of turbulent flow and heat transfer in a mildly expanded channel of IFMIF high flux test module

For the precise thermomechanical design of the high flux test module (HFTM) of IFMIF, in which temperature control of irradiated specimens are done by gas-cooling and heater-heating, estimates for cooling performances of coolant is very essential. In this study, we numerically examined the case of the deformed vessel since the vessel of the HFTM is supposed to be a rectangular duct and the vessel wall is considered to deform easily due to a large pressure difference of several times the atmospheric pressure between the inside and the outside of the vessel. We performed large-eddy simulations (LES) for turbulent heat transfer in the case of deformed, expanded vessel wall. The finite element formulation was used for discretization and the Lagrangian dynamic mixed model was adopted to determine the Smagorinsky constant. A large deformation of the vessel was assumed and comparison of the expanded vessel case with a flat vessel one was made. The cooling performance was found to be insensitive to the vessel deformation because deformations which were acceptable in light of the HFTM design were not quite enough to change the coolant flow drastically.