Experimental and numerical investigation of the thermal performance of the gas-cooled divertor plate concept

Experimental and numerical studies simulating the gas-cooled divertor plate design concept have been carried out. While thermo-fluid and thermo-mechanical analyses have been previously performed to show the feasibility of the divertor plate design and its ability to accommodate a maximum heat flux of up to 10 MW/m2, no experimental data have heretofore been published to support or validate such analyses. To that end, this investigation has been undertaken. A test module with prototypical cross-sectional geometry has been designed, constructed, and instrumented. Experiments spanning the prototypical Reynolds numbers of the helium-cooled divertor have been conducted using pressurized air as the coolant. A second test module where the planar jet exiting the inlet manifold is replaced by a two-dimensional hexagonal array of circular jets over the entire top surface of the inlet manifold has also been tested. The thermal performance of both test modules with and without a porous metallic foam layer in the gap between the outer surface of the inlet manifold and the cooled surfaces of the pressure boundary were directly compared. For a given mass flow rate, the slot design with the metallic foam insert showed the highest heat transfer coefficient, with a pressure drop lower than that of the array of circular jets without foam. Additionally, numerical simulations matching the experimental operating conditions for the two cases without foam were performed using the computational fluid dynamics software package, FLUENT® v6.2. Comparisons of the experimental and numerical pressure drop, temperature, and heat transfer coefficient were made.M.S