THE ENERGY EFFICIENT CONFIGURATIONS OF NATURAL CONVECTION HEAT TRANSFER IN SQUARE ENCLOSURES WITH HEATLINES

Abstract

A steady state natural convection heat transfer is numerically investigated in a two-dimensional square enclosure. One of the side walls of the enclosure is brought to high temperature and the upper wall is insulated. The other walls are partially insulated and the remaining parts of those walls are kept cold in accordance with the area of cold and hot surfaces are equal. The solution is performed for Rayleigh number values between 10⁴ and 10⁶, and for a Prandtl number value of 0.71. The obtained results are presented as local and average Nusselt numbers, streamlines, isotherms and heatlines. It is found that cold and insulated wall configurations have noticeable effects on the flow temperature fields and resulting heat transfer.

Keywords

• Natural convection heat transfer
• square enclosure
• discrete heat sink
• heatline

References

1. [1] Aydin, O. and Yang, W.J., (2000), “Natural Convection in Enclosures with Localized Heating from Below and Symmetrical Cooling from Sides”, International Journal of Numerical Methods for Heat & Fluid Flow, 10, 5, 518-529.
2. [2] Fusegi, T., Hyun, J.M. and Kuwahara, K., (1992), “Numerical Study of Natural Convection in a Differentially Heated Cavity with Internal Heat Generation: Effects of the Aspect Ratio”, Journal of Heat Transfer, 114, 773-777.
3. [3] Aydın, O., Ünal, A. and Ayhan, T., (1999), “A Numerical Study on Buoyancy-Driven Flow in an Inclined Square Enclosure Heated and Cooled on Adjacent Walls”, Numerical Heat Transfer, Part A, 36, 585-599.
4. [4] Sathiyamoorthy, M., Basak, T., Roy, S. and Pop, I., (2007), “Steady Natural Convection Flows in a Square Cavity with Linearly Heated Side Wall(s)”, International Journal of Heat and Mass Transfer, 50, 766-775.
5. [5] Alam, P., Ashok, K., Kapoor, S., Ansari, S.R., (2012), “Numerical Investigation of Natural Convection in Rectangular Enclosure Due to Partial Heating and Cooling at Vertical Walls”, Commun. Nonlinear Sci. Numer. Simulat., 17, 2403-2414.
6. [6] Bilgen, E. and Ben Yedder, R., (2007), “Natural Convection in Enclosure with Heating and Cooling by Sinusoidal Temperature Profiles on One Sides”, International Journal of Heat and Mass Transfer, 50, 139-150.
7. [7] Basak, T., Roy, S. and Balakrishnan, A.R., (2006), “Effects of Thermal Boundary Conditions on Natural Convection Flows within a Square Cavity”, International Journal of Heat and Mass Transfer, 49, 4525-4535.
8. [8] Bazylak, A., Djilali, N., Sinton, D., (2006), “Natural Convection in an Enclosure with Distributed Heat Sources”, Numerical Heat Transfer, Part A, 49, 655-667.

9. [9] Radhwan, A.M., Zaki, G.M., (2000), “Laminar Natural Convection in a Square Enclosure with Discrete Heating of Vertical Walls”, JKAU: Eng. Sci., Vol. 12,No. 2, 83-99.
10. [10] Djoubeir, D., Omar, K., Soufien, C., Saadoun, B., (2014) “Numerical Simulation of Natural Convection in a Square Cavity with Partially Active Vertical and Horizontal Walls”, International Publisher & C.O, Vol.2,.
11. [11] Namprai, A., Witayangkurn, S., (2012), “Fluid Flow and Heat Transfer in Square Cavities with Discrete Two Source-Sink Pairs”, Adv. Studies Theor. Phys., Vol 6, No. 15, 743-753.
12. [12] Chen, T.Z., Chen, L.Y., (2007), “Study of Buoyancy-Induced Flows Subjected to Partially Heated Sources on the Left and Bottom Walls in a Square Enclosure”, International Journal of Thermal Sciences, 46, 1219-1231.
13. [13] Cianfrini, C., Corcione, M., Dell’Omo, P.P., (2005), “Natural Convection in Tilted Square Cavities with Differentially Heated Opposite Walls”, International Journal of Thermal Sciences, 44, 441-451.
14. [14] Kimura, S., Bejan, A., (1983), “The Heatline Visulation of Convective Heat Transfer”, J. Heat Transfer. 105(4), 916-919.
15. [15] Basak, T., Roy, S., (2008), “Role of ‘Bejan’s Heatlines’ in Heat Flow Visulation and Optimal Thermal Mixing of Differentially Heated Square Enclosures”, International Journal of Heat and Mass Transfer, 51, 3486-3503.
16. [16] Deng, Q-H., (2008), “Fluid Flow and Heat Transfer Characteristics of Natural Convection in Square Cavities due to Discrete Source-Sink Pairs”, International Journal of Heat and Mass Transfer, 51, 5949-5957.
17. [17] De Vahl Davis, G., (1983), “Natural Convection of Air in a Square Cavity: A Benchmark Numerical Solution”, International Journal for Numerical Methods in Fluids, 3, pp. 249-264.
18. [18] Ostrach, S., (1988), “Natural Convection in Enclosures”, Journal of Heat Transfer, 10, pp. 1175-1190.
19. [19] Corcione, M., (2003), “Effects of the Thermal Boundary Conditions at the Sidewalls upon Natural Convection in Rectangular Enclosures Heated from Below and Cooled from Above”, International Journal of Thermal Sciences, 42, pp. 199-208.
20. [20] Caronna, G., Corcione, M., and Habib, E., (2009), “Natural Convection Heat and Momentum Transfer in Rectangular Enclosures Heated at the Lower Portion of the Sidewalls and the Bottom Wall and Cooled at the Remaining Upper Portion of the Sidewalls and the Top Wall”, Heat Transfer Engineering, 30(14), 1166–1176.
21. [21] Valencia, A., and Frederick, R.L., (1989), “Heat Transfer in Square Cavities with Partially Active Vertical Walls”, International Journal of Heat and Mass Transfer, Vol.32, pp. 1567-1574.
22. [22] Patankar, S.V., 1980, Numerical Heat Transfer and Fluid Flow, McGraw Hill, New York.