Comparison of turbulence model predictions in rod bundles with supercritical up-flow

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2015, 2016
Bergmann, Cale
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VTT Technical Research Centre of Finland Ltd
Vertical up-flow of supercritical fluid in the subchannel of a heated rod bundle was numerically simulated using the Computational Fluid Dynamics (CFD) codes ANSYS CFX and ANSYS FLUENT. A total of seven cases from three different sets of experiments were simulated. Three-dimensional steady-state predictions of fluid velocity, pressure, and temperature were made using five versions of two-equation RANS turbulence models with accompanying wall treatments. In addition, the temperature distribution in a solid region comprising a heater and sheathing was also computed in some cases. The k-epsilon turbulence model, implemented using CFX and scalable wall functions, provided the numerical results that have the smallest overall deviation from experimental results for three of the seven cases, and predicts the experimental data of the remaining four cases reasonably well, unlike other turbulence models that severely over-predict the experimental data for wall surface temperature.
Supercritical, Turbulence models, Rod bundles, Numerical, CFD, CFX, FLUENT, Heat transfer deterioration
C. Bergmann, S. J. Ormiston and V. Chatoorgoon, "Sensitivity Studies of SST Turbulence Model Parameters on the Prediction of 7-Rod Bundle Benchmark Experiments," in The 7th International Symposium on Supercritical Water-Cooled Reactors (ISSCWR7), Helsinki, Finland, 2015.
C. Bergmann, S. J. Ormiston and V. Chatoorgoon, "Sensitivity Studies of Shear Stress Transport Turbulence Model Parameters on the Prediction of Seven-Rod Bundle Benchmark Experiments," Journal of Nuclear Engineering and Radiation Sciences, vol. 2, no. 1, 2016.