Uniform and non-uniform flows through a PWR-type rod bundle with mixing grids at Reynolds number ranging from 800 up to 70000: pressure loss measurements
Résumé
We present two sets of experiments performed on the METERO-V set-up. METERO-V is a closed loop, equipped with a test section made of two halves of PWR-type rod bundles (8x34 rods) at full scale. The set up allows injection of different flow rates and temperatures at the inlet of each half of rod bundles. METERO-V experimental program focuses on IBLOCA (Intermediate Break Loss of Coolant Accident), SBLOCA (Small Break) and SLB (Steam Line Break) situations where significant 3D effects may occur in the core, with the aim to develop models and to validate them in a separated-effect way for CFD to system thermal-hydraulic scales. We present preliminary results for a homogeneous inflow, varying the Reynolds number from laminar regime to fully turbulent regime. We measure pressure loss along the flow, across the grids and for the bare bundle. For non-symmetrical inlet velocity, we measure also transverse pressure across the test section at different elevations. For the homogeneous injections, the axial pressure drop is successfully compared with available literature models and experimental data. Principle of tests in non-symmetrical configuration is presented.