Thermo-hydraulic flow in a sudden expansion

The paper deals with the turbulent flow of liquid metal directed upwards in a vertical channel featuring a backward-facing step. The vertical wall behind the step is heated at various rates thereby inducing forced and mixed convection. Due to the low Prandtl number of liquid metal flow a data basis for this technically relevant flow type did not exist so far. Here, DNS and LES results are presented to provide detailed information about the statistics of the turbulent motion, budgets of turbulent kinetic energy and other quantities. This information is then further used to develop suitable statistical turbulence models capable of properly covering this flow and similar ones, i.e. forced, mixed and free convection of liquid metals. Finally, the paper reports on the construction of an experiment conceived for exactly the same configuration as simulated, with the purpose of close cross validation between the different approaches.