Natural Convection in Missouri S&T Prismatic Scaled Down Facility Subject to Constant Heat Flux

Previous findings suggest that natural circulation in simplified geometries cannot be directly extended to Prismatic Modular high temperature nuclear Reactor (PMR). Therefore, Missouri S&T constructed a prismatic scaled down dual channel facility and developed advanced fast response flash mounted heat transfer probes (HT) technique. Natural circulation is stimulated within the facility by electrically heating one channel and cooling the second one. The HT sophisticated technique is implemented to measure the local heat transfer coefficient (h) axially along the heated channel which is subjected to constant applied heat flux. Four values of heating intensity were investigated (i.e., 37, 40, 45, 50 watt). Results show that the local heat transfer coefficient (expressed in Nusselt number) is directly proportional to the heating intensity (expressed in Rayleigh number). Also, the results show that natural circulation behavior at channel ends is significantly influenced by the coolant mixing phenomena occurring in the reactor two plena