scholarly journals Performance Assessment of the Commercial CFD Software for the Prediction of the PWR Internal Flow

Author(s):  
Gong Hee Lee ◽  
Young Seok Bang ◽  
Sweng Woong Woo ◽  
Ae Ju Cheong ◽  
Do Hyeong Kim ◽  
...  

As the computer hardware technology develops the license applicants for nuclear power plant use the commercial CFD software with the aim of reducing the excessive conservatism associated with using simplified and conservative analysis tools. Even if some of CFD software developers and its users think that a state of the art CFD software can be used to solve reasonably at least the single-phase nuclear reactor safety problems, there is still the limitations and the uncertainties in the calculation result. From a regulatory perspective, Korea Institute of Nuclear Safety (KINS) has been presently conducting the performance assessment of the commercial CFD software for the nuclear reactor safety problems. In this study, in order to examine the prediction performance of the commercial CFD software with the porous model in the analysis of the scale-down APR+ (Advanced Power Reactor Plus) internal flow, simulation was conducted with the on-board numerical models in ANSYS CFX R.14 and FLUENT R.14. It was concluded that depending on the CFD software the internal flow distribution of the scale-down APR+ was locally somewhat different. Although there was a limitation in estimating the prediction performance of the commercial CFD software due to the limited number of the measured data, CFX R.14 showed the more reasonable predicted results in comparison with FLUENT R.14. Meanwhile, due to the difference of discretization methodology, FLUENT R.14 required more the computational memory than CFX R.14 for the same grid system. Therefore the CFD software suitable to the available computational resource should be selected for the massive parallel computation.

Author(s):  
Corey E. Clifford ◽  
Mark L. Kimber

Abstract Over the past 50 years, an industry-wide shift within the nuclear community has led to increased utilization of computational fluid dynamics (CFD) to supplement nuclear reactor safety (NRS) analyses. Although several “best practice” guidelines exist for individual safety evaluations, comprehensive validation efforts against benchmark-quality experimental data must occur to ensure the accuracy of these numerical models. One such area of interest to the nuclear engineering community is the capacity of computational models to predict heat transfer across a spectrum of buoyancy conditions. In this vein, the present investigation provides a robust assessment of 13 different Reynolds-averaged Navier–Stokes (RANS) turbulence models and their ability to predict thermal system response quantities (SRQs) in buoyancy-influenced forced convection conditions. Using experimental data from the rotatable buoyancy tunnel (RoBuT) as the basis of comparison, the predictive capabilities of each turbulence model are evaluated in both buoyancy-aided and opposed configurations. Thermocouple measurements are mapped to the boundaries of the computational models to permit direct comparisons of various SRQs. ASME standards are used to quantify numerical discretization uncertainties in the modeled results, while a Monte Carlo procedure is developed to account for input uncertainty. Generally, the collection of turbulence models fails to accurately predict thermal SRQs in the buoyancy-aided configuration, while analogous errors in streamwise velocity are observed in the buoyancy-opposed orientation. Both modeling errors are attributed to improper predictions of the turbulent viscosity, which will need to be rectified prior to wide-scale adoption for nuclear reactor safety calculations.


Nature ◽  
1982 ◽  
Vol 300 (5894) ◽  
pp. 677-677
Author(s):  
Jasper Becker

Nature ◽  
1958 ◽  
Vol 181 (4609) ◽  
pp. 601-601

1974 ◽  
Vol 30 (8) ◽  
pp. 5-12 ◽  
Author(s):  
Joel Primack ◽  
Frank Von Hippel

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