Abstract
The effects of the aspect ratio on unsteady solutions through the curved duct flow are studied numerically by a spectral based computational procedure with a temperature gradient between the vertical sidewalls for the Grashof number 100 ⩽ Gr ⩽ 2 000. The outer wall of the duct is heated while the inner wall is cooled and the top and bottom walls are adiabatic. In this paper, unsteady solutions are calculated by the time history analysis of the Nusselt number for the Dean numbers Dn = 100 and Dn = 500 and the aspect ratios 1 ⩽ γ ⩽ 3. Water is taken as a working fluid (Pr = 7.0). It is found that at Dn = 100, there appears a steady-state solution for small or large Gr. For moderate Gr, however, the steady-state solution turns into the periodic solution if γ is increased. For Dn = 500, on the other hand, it is analyzed that the steady-state solution turns into the chaotic solution for small and large Gr for any γ lying in the range. For moderate Gr at Dn = 500, however, the steady-state flow turns into the chaotic flow through the periodic oscillating flow if the aspect ratio is increased.
Similar content being viewed by others
Abbreviations
- Dn :
-
Dean number
- g :
-
gravitational acceleration
- u :
-
velocity component in the x-direction
- Gr :
-
Grashof number
- v :
-
velocity component in the y-direction
- h :
-
half height of the cross section
- w :
-
velocity component in the z-direction
- d :
-
half width of the cross section
- x :
-
horizontal axis
- L :
-
radius of the curvature
- y :
-
vertical axis
- Pr :
-
Prandtl number
- z :
-
axis in the main flow direction
- t :
-
time
- λ :
-
resistance coefficient
- η :
-
curvature of the duct
- ν :
-
kinematic viscosity
- ρ :
-
density
- κ :
-
thermal diffusivity
- ψ :
-
sectional stream function
- µ:
-
viscosity
References
Dean, W. R. Note on the motion of fluid in a curved pipe. Philos. Mag., 4, 208–223 (1927)
Berger, S. A., Talbot, L., and Yao, L. S. Flow in curved pipes. Annual Review of Fluid Mechanics, 35, 461–512 (1983)
Nandakumar, K. and Masliyah, J. H. Swirling flow and heat transfer in coiled and twisted pipes. Advanced Transport Process, 4, 49–112 (1986)
Ito, H. Flow in curved pipes. JSME International Journal, 30, 543–552 (1987)
Cheng, K. C. and Akiyama, M. Laminar forced convection heat transfer in curved rectangular channels. International Journal of Heat and Mass Transfer, 13, 471–490 (1970)
Yee, G., Chilukuri, R., and Humphrey, J. A. C. Developing flow and Heat transfer in strongly curved ducts of rectangular cross section. Transactions ASME Journal of Heat Transfer, 102, 285–291 (1980)
Komiyama, Y., Mikami, F., and Okuni, K. Laminar forced convection heat transfer in curved channels of rectangular cross-section. JSME Int. J. Ser. B, 50, 424–434 (1984)
Thangam, S. and Hur, N. Laminar secondary flows in curved rectangular ducts. Journal of Fluid Mechanics, 217, 421–440 (1990)
Ligrani, P. M., Choi, S., Scallert, A. R., and Skogerboe, P. Effects of Dean vortex pairs on surface heat transfer in curved channel flow. International Journal of Heat and Mass Transfer, 39, 27–37 (1996)
Liu, F. and Wang, L. Analysis on multiplicity and stability of convective heat transfer in tightly curved rectangular ducts. International Journal of Heat and Mass Transfer, 52, 5849–5866 (2009)
Yanase, S. and Nishiyama, K. On the bifurcation of laminar flows through a curved rectangular tube. J. Phys. Soc. Japan, 57, 3790–3795 (1988)
Yanase, S., Kaga, Y., and Daikai, R. Laminar flows through a curved rectangular duct over a wide range of the aspect ratio. Fluid Dyn. Res., 31, 151–183 (2002)
Wang, L. and Yang, T. Periodic oscillation in curved duct flows. Physica D, 200, 296–302 (2005)
Mondal, R. N., Kaga, Y., Hyakutake, T., and Yanase, S. Effects of curvature and convective heat transfer in curved square duct flows. Transactions ASME Journal of Fluids Engineering, 128(9), 1013–1023 (2006)
Mondal, R. N., Kaga, Y., Hyakutake, T., and Yanase, S. Bifurcation diagram for two-dimensional steady flow and unsteady solutions in a curved square duct. Fluid Dyn. Res., 39, 413–446 (2007)
McCormack, P. D., Welker, H., and Kelleher, M. Taylor-Goertler vortices and their effect on heat transfer. Transactions ASME Journal of Heat Transter, 92, 101–112 (1969)
Sturgis, J. C. and Mudawar, I. Single-phase heat transfer enhancement in a curved, rectangular channel subjected to concave heating. International Journal of Heat and Mass Transfer, 42, 1255–1272 (1999)
Mori, Y., Uchida, Y., and Ukon, T. Forced convective heat transfer in a curved channel with a square cross section. International Journal of Heat and Mass Transfer, 14, 1787–1805 (1971)
Chandratilleke, T. T. and Nursubyakto. Numerical prediction of secondary flow and convective heat transfer in externally heated curved rectangular ducts. Int. J. Therm. Sci., 42, 187–198 (2003)
Yanase, S., Mondal, R. N., and Kaga, Y. Numerical study of non-isothermal flow with convective heat transfer in a curved rectangular duct. Int. J. Therm. Sci., 44, 1047–1060 (2005)
Mondal, R. N., Uddin, M. S., and Yanase, S. Numerical prediction of non-isothermal flow through a curved square duct. Int. J. Fluid Mech. Res., 37(1), 85–99 (2010)
Gottlieb, D. and Orazag, S. A. Numerical Analysis of Spectral Methods, Society for Industrial and Applied Mathematics, Philadelphia (1977)
Mondal, R. N. Isothermal and Non-isothermal Flows Through Curved Ducts with Square and Rectangular Cross Sections, Ph. D. dissertation, Okayama University, Japan (2006)
Yanase, S., Mondal, R. N., Kaga, Y., and Yamamoto, K. Transition from steady to chaotic states of isothermal and non-isothermal flows through a curved rectangular duct. J. Phys. Soc. Japan, 74(1), 345–358 (2005)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Mondal, R.N., Islam, S., Uddin, K. et al. Effects of aspect ratio on unsteady solutions through curved duct flow. Appl. Math. Mech.-Engl. Ed. 34, 1107–1122 (2013). https://doi.org/10.1007/s10483-013-1731-8
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10483-013-1731-8