Issue
Korean Journal of Chemical Engineering,
Vol.27, No.3, 759-765, 2010
A numerical study on unsteady natural convection of air with variable viscosity over an isothermal vertical cylinder
The present study deals with the boundary layer flow and heat transfer of unsteady laminar free convection flow past a semi-infinite isothermal vertical cylinder immersed in air. The fluid viscosity is assumed to vary with the temperature. An implicit finite-difference method has been employed to solve the governing non-dimensional boundary layer equations. A parametric study is performed to illustrate the influence of variable viscosity on the velocity and temperature profiles. The numerical results reveal that the viscosity has significant influences on the transient velocity and temperature profiles, average skin-friction coefficient and the average heat transfer rate. The results indicate that as the viscosity parameter increases, the temperature and the skin-friction coefficient increase, while the velocity near the wall and the Nusselt number decrease.
[References]
  1. Sparrow EM, Gregg JL, Trans. of ASME, 78, 1823, 1956
  2. Minkowycz WJ, Sparrow EM, J. Heat Trans., 96, 178, 1974
  3. Fujii T, Uehera H, Int. J Heat Mass Trans., 13, 607, 1970
  4. Lee HR, Chen TS, Armaly BF, J. Heat Trans., 110, 103, 1988
  5. Dring RP, Gebhart B, J. Heat Trans., 88, 246, 1966
  6. Velusamy K, Garg VK, Int. J. Heat Mass Trans., 35, 1293, 1992
  7. Rani HP, Heat and Mass Trans., 40, 67, 2003
  8. Schlichting H, Boundary layer theory, McGraw-Hill, New York, 1979
  9. Kakac S, Shah RK, Aung W, Handbook of single-phase convective heat transfer, John Wiley & Sons, New York, 1987
  10. Cengel Y, Fluid Mechanics fundamentals & applications, McGraw-Hill, New York, 2006
  11. Molla MM, Hossain MA, Gorla RSR, Heat Mass Trans., 41, 594, 2005
  12. Kafoussius NG, Rees DAS, Acta Mechanica., 127, 39, 1998
  13. Gray J, Kassory DR, Tadjeran H, J. Fluid Mech., 117, 233, 1982
  14. Pop I, Gorla RSR, Rashidi M, Int. J. Eng. Sci., 30, 1, 1992
  15. Kafoussias NG, Williams EW, Int. J. Eng. Sci., 33, 1369, 1995
  16. Elbashbeshy EMA, Bazid MAA, J. Phys. D: Applied Physics, 33, 2716, 2000
  17. Abo-Eldahab EM, Gendy EI, Phys. Scripta, 62, 321, 2000
  18. Hossain MA, Munir MS, Pop I, Int. J. Thermal Sci., 40, 366, 2001
  19. Touloukian YS, Saxena SC, Hestermans P, Thermophysical properties of matter, Viscosity, The TPRC Data Series, Plenum, New York, 1975
  20. Carnahan B, Luther HA, Wilkes JO, Applied numerical methods, John Wiley & Sons, New York, 1969
  21. Ganesan P, Rani HP, Heat Mass Trans., 33, 449, 1998
  22. Incropera FP, Dewitt DP, Fundamentals of heat and mass transfer, John Wiley & Sons, New York, 2007