Direct Numerical Simulation of Turbulent Mixed Convection in Heated Vertical Annulus

수직 동심 환형관 내의 난류혼합대류 현상에 관한 직접수치모사

  • Published : 2009.09.01


Turbulent mixed convection in heated vertical annulus is investigated using Direct Numerical Simulation (DNS) technique. The objective of this study is to find out the effect of buoyancy on turbulent mixed convection in heated vertical annulus. Downward and upward flows with bulk Reynolds number 8500, based on hydraulic diameter and mean velocity, have been simulated to investigate turbulent mixed convection by gradually increasing the effect of buoyancy. With increased heat flux, heat transfer coefficient first decreases and then increases in the upward flow due to the effect of buoyancy, but it gradually increases in downward flow. The mean velocity and temperature profiles can not be explained by the wall log laws due to the effect of buoyancy, too. All simulation results are in good quantitative agreement with existing numerical results and in good qualitative agreement with existing experimental results.



  1. Yoo, J. W., Yoo, J. Y. and Choi, H. C., 2003, 'Direct Numerical Simulation of Heated Vertical Air Flows in Fully Developed Turbulent Mixed Convection,' Int. J. Heat Mass Transfer, Vol. 46, No. 9, pp. 1613-1627
  2. Jackson, J. D., Cotton, M. A., Axcell, B. P., 1989, 'Studies of Mixed Convection in Vertical Tubes,' Int. J. Heat Fluid Flow, Vol. 10, No. 1, pp. 2-15
  3. Parlatan, Y., Todreas, N. E. and Driscoll, M. J., 1996, 'Buoyancy and Property Variation Effects in Turbulent Mixed Convection of Water in Vertical Tubes,' J. Heat Transfer, Vol. 118, No. 2, pp. 381-387
  4. Nouri, J. M., Umur, H. and Whitelaw, J. H., 1993, 'Flow of Newtonian and Non-Newtonian Fluids in Concentric and Eccentric Annuli,' J. of Fluid Mech., Vol. 253, pp. 617-641
  5. Escudier, M. P., Gouldson, I. W. and Jones, D. M., 1995, 'Flow of Shear-thinning Fluids in a Concentric Annulus,' Exp. in Fluids, Vol. 18, pp. 225-238
  6. Chung, S. Y., Rhee, G. H. and Sung, H. J., 2002, 'Direct Numerical Simulation Of Turbulent Concentric Annular Pipe Flow. Part 1: Flow Field,' Int. J. Heat Fluid Flow, Vol. 23, pp. 426-440
  7. Xu, Z., 2002, 'Study of the Influences of Buoyancy on Turbulent Flow and Heat Transfer in a Vertical Passage of Annular Cross-section,' Ph. D. Thesis, University of Manchester
  8. Kang, S., Patil, B., Zarate, J. A. and Roy, R. P., 2001, 'Isothermal and Heated Turbulent Upflow in a Vertical Annular Channel - Part I. Experimental Measurements,' Int. J. Heat Mass Transfer, Vol. 44, pp. 1171-1184
  9. Zarate, J. A., Roy, R. P. and Laporta, A., 2001, 'Isothermal and Heated Turbulent Upflow in a Vertical Annular Channel - Part II. Numerical Simulations,' Int. J. Heat Mass Transfer, Vol. 44, pp. 1185-1199
  10. Akselvoll, K. and Moin, P., 1995, 'Large Eddy Simulation of Turbulent Confined Coannular Jets and Turbulent Flow Over a Backward Facing Step,' Mech. Eng. Dept. Report TF-63, Stanford University
  11. Buchhave, P., George, W. K. and Lumley, J. L., 1979, 'The Measurement of Turbulence with the Laser-Doppler Anemometer,' Annual Review of Fluid Mechanics, Vol. 11, pp. 443-503
  12. Shen, Y., Xia, K. Q. and Tong, P., 1995, 'Measured Local-Velocity Fluctuations in Turbulent Convection,' Phys. Rev. Lett., Vol. 75, No. 3, pp. 437-440
  13. van Maanen, H. R. E., 1999, 'Retrieval of Turbulence and Turbulence Properties from Randomly Sampled Laser-Doppler Anemometry Data with Noise,' Ph. D. Thesis, Technische Universiteit Delft