DOI QR코드

DOI QR Code

PREDICTION OF THERMAL STRATIFICATION IN A U-BENT PIPE: A URANS VALIDATION

  • Pellegrini, M. (Department of Nuclear Engineering, Tokyo Institute of Technology) ;
  • Endo, H. (Japan Nuclear Energy and Safety Organization (JNES)) ;
  • Ninokata, H. (Department of Nuclear Engineering, Tokyo Institute of Technology)
  • 투고 : 2010.12.30
  • 심사 : 2011.06.09
  • 발행 : 2012.02.25

초록

In the present study, CFD is employed to investigate phenomena occurring during a process of thermal stratification in U-bent pipes at transitional Reynolds number. URANS evaluation had been chosen for its low computational costs during transient analysis and for the evaluation of modeling performance in these conditions. Application of CFD at transitional Reynolds number and buoyancy driven flows indeed contains deeper uncertainties in relation to the range of applicability for hydrodynamic and thermal models. The methodology applied in the work points out, through validations with the basic problems constituting the complex stratified phenomenon, the applicability of the current turbulence modeling. Accurate predictions have been found in relation to transitional Reynolds number in bent pipes and region of stability induced by the gravitational field. On the other hand the defects introduced in the unstable region of the U bent pipe, are discussed in relation to the adopted modeling.

키워드

참고문헌

  1. NRC, Unexpected piping movement attributed to thermal stratification, Inform. Notice 88-80, October 7, (1988).
  2. L. Wolf, Hafner, M. Geiss, E. Hanjosten, G. Katzenmeier, "Results of HDR-experiments for pipe loads under thermally stratified flow conditions," Nucl. Eng. and Des. 137, 387-404 (1992). https://doi.org/10.1016/0029-5493(92)90262-T
  3. A. Talja, E. Hanjosten, "Results of thermal stratification tests in a horizontal pipe line at the HDR-facility," Nucl. Eng. Des. 118, 29-41 (1990). https://doi.org/10.1016/0029-5493(90)90083-A
  4. A. B. Cortesi, G. Yadigaroglu, S. Banerjee, "Numerical investigation of the formation of the three-dimensional structures in stably stratified mixing layers", Physics of Fluids, Vol. 10, No. 6, 1998, pp. 1449-1473. https://doi.org/10.1063/1.869667
  5. M. Ohtsuka, T. Ikeda M. Yamakawa, Y. Shibata, S. Moriya, S. Ushijima, K. Fujimoto, (1988) "Similarity rules of thermal stratification phenomena for water and sodium", 4th International conference on liquid metal engineering and technology, Vol. 2 Sec. 420.1.
  6. V. K. Dhir, R. C. Amar, J. C. Mills, A one dimensional model for the prediction of stratification in horizontal pipes subjected to fluid temperature transient at inlet, Part I & II, Nucl. Eng. Des. 107, 307-314 (1988). https://doi.org/10.1016/0029-5493(88)90038-6
  7. Viollet P.L., (1987a) "Observation and numerical modelling of density currents resulting from thermal transients in a non rectilinear pipe", Journal of Hydraulic Research, 25, No. 2 (1987).
  8. Viollet P.L., (1987b) "The modeling of turbulent recirculating flows for the purpose of reactor thermal-hydraulic analysis", Nucl. Eng. and Des., 99, 365-377 (1987). https://doi.org/10.1016/0029-5493(87)90133-6
  9. Viollet P.L, J.P. Benque, J. Goussebaile, (1987) "Twodimensional numerical modeling of nonisothermal flows for unsteady thermal-hydraulic analysis", Nucl. Sci. Eng., 84, 350-372 (1987).
  10. STAR-CCM+ Version 5.02 User guide.
  11. E. Baglietto and H. Ninokata, "Anisotropic eddy viscosity modeling for application in industrial engineering internal flows," Int. J. Transport Phenomena, 8, (2006).
  12. F.S. Lien, W.L. Chen, M.A. Leschziner, (1996), "Low- Reynolds number eddy-viscosity modelling based on nonlinear stress-strain/vorticity relations," Proc. 3rd Symp. on Engineering Turbulence Modelling and Measurements, 27-29 May, Crete, Greece.
  13. S. Kenjeres, K. Hanjalic, "Convective rolls and heat transfer in finite-length Rayleigh-Benard convection: A twodimensional numerical study," Physical Review E, , 7987- 7998, (2000).
  14. J. G. M. Eggels, F. Unger, M. H. Weiss, J. Westerweel, R. J. Adrian, R. Friedrich, F. T. M. Nieuwstadt, "Fully developed turbulent pipe flow: a comparison between direct numerical simulation and experiment," J. Fluid Mech. 268, 175-209 (1994). https://doi.org/10.1017/S002211209400131X
  15. M.J den Toonder, F.T.M Nieuwstadt, "Reynolds number effects in a turbulent pipe flow for low to moderate Re" Phys. Fluids, 9 (11), November (1997).
  16. Wolfshtein M., "The velocity and temperature distribution in one-dimensional flow with turbulence augmentation and pressure gradient," Int. J. Heat Mass Transfer, 12, 301-318, (1968). https://doi.org/10.1016/0017-9310(69)90012-X
  17. M.J. Tunstall, J.K. Harvey, "On the effect of a sharp bend in a fully developed turbulent pipe-flow," J. Fluid Mech., 34, part 3, pp. 595-608. https://doi.org/10.1017/S0022112068002107
  18. M. Tanaka, H. Ohshima, H. Yamano, K. Aizawa, T. Fujisaki, (2009), "Application of U-RANS to elbow pipe flow with small curvature radius under high Reynolds number condition," Proceedings of International Congress of Advances in Nuclear Power Plants ICAPP 2009, 10-14 May, Tokyo, Japan.
  19. F. Rutten, W. Schroder, M. Meinke, "Large eddy simulation of low frequency oscillations of the Dean vortices in turbulent pipe bend flows," Phys. Fluids, 17, 035107-035107-11 (2005). https://doi.org/10.1063/1.1852573
  20. Ch. Brucker, "A time-recording DPIC-study of the swirl switching effect on a $90{^{\circ}}$ bend flow," Proceedings of the Eight International Symposium on Flow Visualization, Sorrento,Italy, 1998.

피인용 문헌

  1. Algebraic Turbulent Heat Flux Model for Prediction of Thermal Stratification in Piping Systems vol.181, pp.1, 2013, https://doi.org/10.13182/NT13-A15763