COMPUTATIONAL FLUID DYNAMICS MODELING APPROACH TO EVALUATE VSC – 17 DRY STORAGE CASK THERMAL
A numerical simulation of flow and heat transfer in a ventilated concrete dry storage cask system–17 (VSC–17) is performed and results compared with experimental data to assess the validity of the computational approach. The measurements of steady state temperature distributions on the cask surface, concrete surface, air flow channels, and fuel canister guide are available. Numerical simulations were carried out for normal operating conditions, where both the inlet and outlet vents are open, and for off-normal condition when normal air circulation is interrupted because of blocked vents. Results include the flow and temperature pattern in the ventilated storage system. Computed results were compared with experimental data for axial temperature distribution along the fuel assembly and radial temperature distribution along the storage assembly system. The effect of the turbulence model on temperature distribution pattern was also studied. For all the simulated cases, the computed results showed a trend similar to the experimental observation but did not model exactly. Computed peak cladding temperature in all the simulation cases was slightly higher than the experimental data. Heat transfer results showed some variation due to difference in backfill gas. A study of different k-ε and k-ω turbulence models showed very little effect on temperature distribution.
Thermal-fluid flow analysis and demonstration test of a spent fuel storage system
Abstract Thermal-fluid flow analysis and demonstration test were performed for a spent fuel storage system. The commercial computational fluid dynamics (CFD) code, FLUENT was used for the numerical analysis. Effective thermal conductivities of a spent fuel assembly and a fuel basket were derived to optimize a thermal analysis model. Also, a porous model, which can simplify a complex configuration of a fuel assembly, was used in the thermal analysis. Demonstration test were performed to verify the thermal analysis method and procedure using a half scaled-down model and an electrically heated dummy fuel. The numerical analysis results were compared with the experimental data. Thermal analyses of the storage system were carried out for normal and off-normal conditions by using the verified analysis method.
Frequency selective surface design for blinds applications
In this paper, the reconfigurable blind structure with frequency selective surfaces(FSS) for the building applications are presented. Frequency transmission characteristics for different angles of the proposed blind-FSSs are investigated and verified through simulation and measurement. The simulation results show that we can implement the reconfigurable blind-FSS for multiband wireless applications. To verify the proposed paper, two kinds of blind-FSSs, crossed dipole FSS and circular ring FSS are fabricated and measurements are performed for different angles. The proposed structure in this paper which is very simple, can be easily applied to any planar surface for wireless security applications at low cost.