Measurements for verification and validation of thermal-hydraulic computer code used for thermal-hydraulic analysis of VVER440 typical fuel assembly

• Published in: Measurement : journal of the International Measurement Confederation Vol. 171; p. 108787
• Main Authors: Ézsöl, György, Hutli, Ezddin, Valér, Gottlasz, Gábor, Zsiros
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.02.2021; Elsevier Science Ltd
• Subjects: Assembly; Computational fluid dynamics; Flow velocity; Fuel; Fuels; Heat transfer; Hydraulics; Nuclear fuels; Pitot tube; Pitot tubes; Pressure; Pressure drop; Spacer; Stress concentration; Studies; Turbulent flow; Velocity; Velocity distribution; Pitot tube; Velocity; Pressure; Spacer; Fuel
• ISSN: 0263-2241; 1873-412X
• DOI: 10.1016/j.measurement.2020.108787

•Velocity measurements using a Pitot tube was created to validate the computer code.•Two turbulent models were used in the code for thermal-hydraulic analysis.•A test fuel assembly model of 19 rods with spacers was used in the measurements.•The performance of total pressure drops was measured for two kinds of spacers.•A comparison between the outcome of calculations and the measurements was done. The paper contains experimental data and analysis of the velocity distribution and pressure drop of turbulent flow through a fuel bundle of 19 rods as a partial model of the VVER-440 reactor core. Also, results from the code calculations at the outlet of the test assembly at different flow rates and comparison with experimental data are presented. A pitot tube was used to measure the velocity and pressure drop. Detailed measurements of the velocity distribution in a fuel bundle are done in a fully developed turbulent flow region. Moreover, detailed measurements of the pressure drop of wire and spacer grids typical for PWRs are discussed together with the total pressure drops performance. The experimental result was compared with the predictions by our code and good agreement was found. The calibration protocol and uncertainties of the measurements are presented.