CFD investigation of flow in the MATIS-H test facility

Abstract In this paper steps of calculations for a bare rod bundle and so-called swirl type spacer grid are showed and the effects of choice of model details are examined. The modeled pin bundle and spacer grid geometry are related to rectangular western type PWR fuel assemblies. First a CFD model has been developed for a subchannel of the MATIS-H test facility in order to carry out a mesh independence study. Based on the results a model for the half cross-section of the test bundle has been developed and calculations are carried out with different turbulence models. Translational periodicity is applied in axial direction in order to calculate a fully developed flow, which will be used as inlet boundary condition for spacer grid calculations. Results are compared with LDA (Laser Doppler Anemometry) measurements published in the frame of the OECD NEA MATIS-H benchmark. As a last step a model for rod bundle incorporating swirl type spacer grid is developed and calculations are carried out with different turbulence models using the results of the bare rod bundle simulations as inlet boundary conditions.