CFD Validation With a PIV Provided Experimental Data for the Coolant Velocity Measurement in Reactor Vessel Down-Comer

The description of the fluid flow and the coolant velocity field within a Pressurized Water Reactor (PWR), for the safety analysis is always desirable. In this work, a validation of CFD code ANSYS Fluent performed in the frame of experimental investigations to study the velocity field of coolant flow in a single phase at a reactor vessel down-comer. Under steady-state conditions. Several Experiments using Particle Image Velocimetry, have done at small hemispherical vessel, which designed by the College of Nuclear science and Technology at Harbin Engineering University (HEU) to obtain experimental data for velocity field. The measurements of the fluid flow velocities at two different locations as investigation area in the down-comer under the inlet part, for two different inlets velocities have experimentally calculated and comprehensively simulated using FLUENT. A 3D model of hemispherical cylinder, created by commercial package SolidWorks 2016 and star –CCM code has used as tool for geometry meshing and the simulations process performed with ANSYS-FLUENT code. RANS was first calculated with boundary conditions such as the velocity used at the inlet and the outlet. Two different locations were been selected as in the experimental model and the velocity has measured. The results of CFD analyses demonstrated very good agreement with the experimental data. The results that obtained by the experiment and Fluent help to understand the velocity distribution in the down-comer.