| Thermal-fluid modeling of the Missouri University of Science and Technology Reactor (MSTR) was carried out using a computational fluid dynamics code (CFD), STAR-CCM+. First, a three-dimensional parallel-plate model was developed, and the cosine-shaped heat flux was applied to the MSTR core. Simulation results for fluid flow under natural convection condition show coolant temperature and velocity as a function of core power. A characteristic equation for the parallel-plate model was obtained based on Forchheimer's flow equation. The inertial resistance tensor and viscous resistance tensor were found to be 281005 kg/m.;4 and 7121.6 kg/m.;3 respectively. The MSTR core was then definedas a porous region with porosity 0.7027. A second model was developed to study convection within a section of the MSTR includes 3 fuel elements (power density of 1.86E+6 Wm-3) in one third of the reactor pool volume. For validation work, both plume temperature and pool temperature measurements were recorded at several locations within the MSTR pool. At 200kW, the temperature field was consistent with the pool temperature data at 15 locations. A third model included the workings of an eductor outlet from, and inlet into the active cooling system to predict heat removal capability. The major contribution of this study is to explain the thermal flow in the MSTR channels and pool, and to provide a framework for supporting reactor license renewal, and power uprate plans. |
