AbstractThe FliHy (Flibe Hydrodynamics) facility was constructed at UCLA to study open channel turbulent flow and heat transfer of low-thermal and -electrical conductivity fluids. At present, water is used as a stimulant fluid for molten salt, e.g. Flibe. A similarity analysis matched the dimensionless parameters in the experiment with those in the ARIES-RS First Wall design. Unlike previous studies of open channel flow, the goal of the present one is to study supercritical flow regimes (Fr>1), in which the surface waves are amplified and heat transfer is enhanced due to surface renewal. The paper describes the facility and gives the results of measurements of the flow thickness and their analysis.