This work presents a validation of NEPTUNE CFD against plunging water jet experiments by Iguchi et al., with sensitivity tests to turbulence modelling. NEPTUNE CFD is the thermal-hydraulic Two-Phase CFD tool of NURESIM (European Platform for Nuclear Reactor Simulations), and is designed to simulate two-phase flow in all situations encountered in Nuclear Power Plants (NPP). The Iguchi’s flow configuration is likely to share common physical features with the Emergency Core Cooling (ECC) injection in a Pressurized Water Reactor (PWR) uncovered cold leg during a SBLOCA (Small Break Loss Of Coolant Accident). In the experiment, the water was injected vertically downward a straight circular pipe into a cylindrical vessel containing water. Mean velocity and turbulent fluctuations are measured below the jet at several depths below the free surface. The work aimed at studying the influence of several models on two-phase flow prediction and then validating results against measurements. Both standard and modified turbulence models were tested. A single-phase jet case was also simulated and compared with both measurements and two-phase calculations, to investigate bubble entrainment influence on turbulence prediction. The calculated mean velocity field was always in quite good agreement with experimental data, while turbulence intensity was generally good with some underestimation far from the jet axis region.
Validation of Neptune CFD Module With Data of a Plunging Water Jet Entering a Free Surface
D'AURIA, FRANCESCO SAVERIO
2007-01-01
Abstract
This work presents a validation of NEPTUNE CFD against plunging water jet experiments by Iguchi et al., with sensitivity tests to turbulence modelling. NEPTUNE CFD is the thermal-hydraulic Two-Phase CFD tool of NURESIM (European Platform for Nuclear Reactor Simulations), and is designed to simulate two-phase flow in all situations encountered in Nuclear Power Plants (NPP). The Iguchi’s flow configuration is likely to share common physical features with the Emergency Core Cooling (ECC) injection in a Pressurized Water Reactor (PWR) uncovered cold leg during a SBLOCA (Small Break Loss Of Coolant Accident). In the experiment, the water was injected vertically downward a straight circular pipe into a cylindrical vessel containing water. Mean velocity and turbulent fluctuations are measured below the jet at several depths below the free surface. The work aimed at studying the influence of several models on two-phase flow prediction and then validating results against measurements. Both standard and modified turbulence models were tested. A single-phase jet case was also simulated and compared with both measurements and two-phase calculations, to investigate bubble entrainment influence on turbulence prediction. The calculated mean velocity field was always in quite good agreement with experimental data, while turbulence intensity was generally good with some underestimation far from the jet axis region.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
