Development of Unstructured Mesh-Based Numerical Method for Sodium-Water Reaction Phenomenon

AbstractWhen pressurized water or vapor leaks from a failed heat transfer tube in a steam generator (SG) of sodium-cooled fast reactors, a high-velocity, high-temperature jet with sodium-water chemical reaction may cause wastage on the adjacent tubes. For safety assessment of the SG, a computational fluid dynamics code SERAPHIM, in which a compressible multicomponent multiphase flow with sodium-water chemical reaction is computed, has been developed. The original SERAPHIM code is based on the finite difference method. In this study, an unstructured mesh-based numerical method was developed and introduced into the SERAPHIM code to advance a numerical accuracy for a complex-shaped domain including multiple heat transfer tubes. The multiphase flow under the tube failure accident is calculated by the multifluid model considering compressibility. The governing equations are solved by the Highly Simplified Marker And Cell (HSMAC) method. The original HSMAC method was modified for compressible multiphase flows i...