This work presenfs a validation aJNEPTUNE_CFD against plunging water jet experiments by 19uchi et al., with sensitivity tests lo turbulence modeling. NEPTUNE_CFD is the thermal-hydraulic two-phase computational fluid dynamics lool oJ NURESIM (European Platform for Nuclear Reactor Simulations) Qnd is designed fo simulate two-phase flow in situa/ians encountered in nuclear power plan!s. /guchi et al. sfiow configuration shares common physicalfeatures with the emergency core cooling injection in a pressurized water reactor uncovered cold leg during a small-break lossof- coolan! accident. This work contributes to the validatiorl ofrhe NEPTUNE_CFD code capability lo predict the turhulence below a free suiface produced by a plunging jet. In rhe experiment, the water was injected verri-cally down a straight circular pipe into a cylindrical vessel containing water. Mean velocity and turbulent fluctuations were measured below the jet at several depths below the free suiface. The influence of several models on code predictions was investigated, and both standard and modified turbulence models were tested. A single-phase jet case was also simulated and compared with both measurements and rwo-phase calculations, to investigate bubble entrainment influence on turbulence prediction. The calculated mean velocity field was always in quite good agreement with lhe experimental data, while the turhulence intensity was generally good with some underestimarioll 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
2009-01-01
Abstract
This work presenfs a validation aJNEPTUNE_CFD against plunging water jet experiments by 19uchi et al., with sensitivity tests lo turbulence modeling. NEPTUNE_CFD is the thermal-hydraulic two-phase computational fluid dynamics lool oJ NURESIM (European Platform for Nuclear Reactor Simulations) Qnd is designed fo simulate two-phase flow in situa/ians encountered in nuclear power plan!s. /guchi et al. sfiow configuration shares common physicalfeatures with the emergency core cooling injection in a pressurized water reactor uncovered cold leg during a small-break lossof- coolan! accident. This work contributes to the validatiorl ofrhe NEPTUNE_CFD code capability lo predict the turhulence below a free suiface produced by a plunging jet. In rhe experiment, the water was injected verri-cally down a straight circular pipe into a cylindrical vessel containing water. Mean velocity and turbulent fluctuations were measured below the jet at several depths below the free suiface. The influence of several models on code predictions was investigated, and both standard and modified turbulence models were tested. A single-phase jet case was also simulated and compared with both measurements and rwo-phase calculations, to investigate bubble entrainment influence on turbulence prediction. The calculated mean velocity field was always in quite good agreement with lhe experimental data, while the turhulence intensity was generally good with some underestimarioll far from the jet axis region.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
