Browse > Article
http://dx.doi.org/10.6112/kscfe.2012.17.4.041

COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF THERMAL STRATIFICATION IN THE UPPER PLENUM OF THE MONJU FAST BREEDER REACTOR  

Choi, S.K. (Fast Reactor Design Division, Korea Atomic Energy Research Institute)
Lee, T.H. (Fast Reactor Design Division, Korea Atomic Energy Research Institute)
Publication Information
Journal of computational fluids engineering / v.17, no.4, 2012 , pp. 41-48 More about this Journal
Abstract
A numerical analysis of thermal stratification in the upper plenum of the MONJU fast breeder reactor was performed. Calculations were performed for a 1/6 simplified model of the MONJU reactor using the commercial code, CFX-13. To better resolve the geometrically complex upper core structure of the MONJU reactor, the porous media approach was adopted for the simulation. First, a steady state solution was obtained and the transient solutions were then obtained for the turbine trip test conducted in December 1995. The time dependent inlet conditions for the mass flow rate and temperature were provided by JAEA. Good agreement with the experimental data was observed for steady state solution. The numerical solution of the transient analysis shows the formation of thermal stratification within the upper plenum of the reactor vessel during the turbine trip test. The temporal variations of temperature were predicted accurately by the present method in the initial rapid coastdown period (~300 seconds). However, transient numerical solutions show a faster thermal mixing than that observed in the experiment after the initial coastdown period. A nearly homogenization of the temperature field in the upper plenum is predicted after about 900 seconds, which is a much shorter-term thermal stratification than the experimental data indicates. This discrepancy is due to the shortcoming of the turbulence models available in the CFX-13 code for a natural convection flow with thermal stratification.
Keywords
MONJU Fast Breeder Reactor; Thermal Stratification; Natural Convection; Porous Media method; Computational Fluid Dynamics;
Citations & Related Records
연도 인용수 순위
  • Reference
1 1988, Vidil, R., Grand, D. and Leroux, F. "Interaction of Recirculation and Stable Stratification in a Rectangular Cavity Filled with Sodium," Nucl. Eng .Des., Vol.105, pp.321-332.   DOI
2 1990, Ieda, Y., Maekawa, I., Muramatsu, T. and Nakanish, S. "Experimental and Analytical Studies of the Thermal Stratification Phenomenon in the Outlet Plenum of Fast Breeder Reactors," Nucl. Eng. Des., Vol.120, pp.403-414.   DOI
3 1990, Tanaka, N., Moriya, S., Ushijima, S., Koga, T. and Eguchi, Y. "Prediction Method for Thermal Stratification in a Reactor Vessel," Nucl. Eng. Des., Vol.120, pp.395-402.   DOI
4 1994, Muramatsu, T. and Ninokata, H. "Investigation of Turbulence Modeling in Thermal Stratification Analysis," Nucl .Eng. Des., Vol.150, pp.81-93.   DOI   ScienceOn
5 1997, Doi, Y. and Muramatsu, T. "Numerical Analysis of Thermal Stratification Phenomena in Upper Plenum of Fast Breeder Reactor," Proc. of 8th Int. Topical Meetingon Nuclear Reactor Thermal Hydraulics, Kyoto, Japan.
6 1989, Ince, N. Z. and Launder, B. E. "On the Computation of Buoyancy-Driven Turbulent Flows in Rectangular Enclosures," Int. J. Heat Fluid Flow, Vol.10, pp.110-117.   DOI   ScienceOn
7 2008, Choi, S. K. and Kim, S. O. "Treatment of Turbulent Heat Fluxes with the Elliptic-Blending Second-Moment Closure for Turbulent Natural Convection Flows," Int. J. Heat Mass Transfer, Vol.51, pp.2377-2388.   DOI
8 2002, Hanjalic, K. "One-Point Closure Models for Buoyancy-Driven Turbulent Flows," Annu. Rev. Fluid Mech., Vol.34, pp.321-347.   DOI
9 2006, Choi, S. K. and Kim, S. O. "The Role of Turbulence Models for Predicting a Thermal Stratification," ASME J. PVT, Vol.128, pp.656-662.
10 1988, Chen, H. C. and Patel, V. C. "Near-Wall Turbulence Models for Complex Flows Including Separation," AIAA J., Vol.26, pp.641-648.   DOI   ScienceOn
11 1994, Menter, F. R. "Two Equation Eddy-Viscosity Turbulence Models for Engineering Applications," AIAA J., Vol.32, pp.1598-1604.   DOI   ScienceOn
12 2002, Medic, G. and Durbin, P. A. "Toward Improved Prediction of Heat Transfer on Turbine Blades," ASME, J. Turbomach., Vol.124, pp.187-192.   DOI   ScienceOn
13 2002, Manceau, R. and Hanjalic, K. "Elliptic Blending Model : A New Near-Wall Reynolds-Stress Turbulence Closure," Phys. Fluids, Vol.14, pp.744-754.   DOI
14 2009, Blind, V. Bieder, U. and Sofu, T. "Benchmark Analysis of Sodium Natural Convection in the Upper Plenum of the MONJU Reactor Vessel - Preparation of a Simplified Model for the Upper Core Structure," CEA Report. DEN/CAD/DER/SSTH/ LMDL/NT/ 2009-105A.
15 2011, Bieder, U. et al. "TRIO_U Analysis of Natural Convection in the Upper Plenum of the MONJU Reactor," Proceedings of the 14th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Toronto, Canada.