A Benchmark CFD Calculation for a Cross Flow between Fuel Blocks of a Prismatic VHTR

The computational fluid dynamics (CFD) technology has been successfully applied to many industrial engineering areas such as aircraft and vehicles. However, it is generally accepted that the CFD codes, even if they are commercial ones, require more sufficient validations to apply to the analysis and design of a very high temperature reactor (VHTR). One of the interesting phenomena of a prismatic VHTR is a cross flow between fuel blocks of a prismatic reactor. The CFD simulation of the phenomena is complex since laminar to turbulent transitions occur around the cross flow gap. It is considered that any turbulence model has not been generally accepted yet for laminar to turbulent transitions and their mixture flows. In this work, a CFD benchmark calculation has been made against the JAEA experiment to investigate the applicability of the existing CFD technology to a cross flow phenomena in fuel blocks of a VHTR