Hydrodynamic models and correlations for bare and wire-wrapped hexagonal rod bundles — Bundle friction factors, subchannel friction factors and mixing parameters

Abstract Consistent hydrodynamic models for subchannel friction factors and mixing parameters in wire-wrapped rod bundles have been developed for use in subchannel analysis codes. Both flow regime and geometry effects are taken into account in these models. The laminar, transition and turbulent flow regimes are covered for the range of liquid metal fast breeder reactor (LMFBR) rod bundles of design interest. Correlations based on the models for the subchannel friction factor and mixing parameters are calibrated by the available world data. This data includes recent 37-pin hydrodynamic experiments with a geometry between that of typical fuel and blanket assembly design performed by the authors. Specific correlations are presented for subchannel and bundle friction factors, flow split, enhanced eddy diffusivity and the peripheral wire induced swirl velocity.