Bypass Flow Study

Abstract

Fluid dynamics experiments are being conducted in the matched-index-of-refraction flow system at the Idaho National Laboratory to develop benchmark databases. The data will be used to assess computational fluid dynamics solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element or upper reflector block geometries of typical modular high-temperature gas-cooled reactors in the limiting case of negligible buoyancy and constant fluid properties. The experiments use particle image velocimetry to measure the velocity fields that will populate the bypass flow study database. The matched-index-of-refraction modular high-temperature gas-cooled reactor bypass flow experiment measures flow velocity fields in the coolant channels and interstitial gaps between typical prismatic block standard fuel elements (SFEs) or upper reflector blocks.