COMPUTATIONAL ANALYSIS OF INSERTED POROUS BLOCKS INTO HORIZONTAL CONCENTRIC ANNULI IN MIXED CONVECTION MODE

Year 2018, Volume: 4 Issue: 1, 1692 - 1701, 12.12.2017

Yacine Ould-amer

https://doi.org/10.18186/journal-of-thermal-engineering.364958

Abstract

This study numerically investigates
the effect of porous blocks thickness on laminar mixed convection in a horizontal
annulus. With attached four porous blocks on the inner cylinder, steady 3D
laminar mixed convection is presented for the fully developed region of
horizontal concentric annuli.

Results are presented for two values
of porous blocks thickness and a range of the values of the Grashoff number,
Darcy number and the conductivity ratio between the porous medium and the fluid.
Results are presented in the form of contours plots of the streamlines and for
the temperature isotherms, and in terms of the overall heat transfer
coefficients and friction factor.

The average Nusselt number increases
significantly with an increase of the thickness of porous blocks. With the use
of the four porous blocks, the friction factor is consequently increased
compared with the situation without porous blocks. The decrease of the Darcy
number leads to an increase of the friction factor. 

If the fully fluid case is taken as
a reference, the use of porous blocks is justified only when the ratio of the
average Nusselt number to the friction factor is enhanced.

Keywords

Renewable Mixed Convection, Concentric Annuli, Porous, Thickness

References

• [1] Huetz, J., & Petit, J. P. (1974). Natural and Mixed Convection in Concentric Annular Spaces—Experimental and Theoretical Results for Liquid Metals. In 5th International Heat Transfer Conference, Tokyo (Vol. 3, pp. 169-172).
• [2] Nguyen, T. H., Vasseur, P., Robillard, L., & Shekar, B. C. (1983). Combined free and forced convection of water between horizontal concentric cylinders. Journal of Heat Transfer, 105(3), 498-504.
• [3] Hattori, N. (1979). Combined free and forced convection heat transfer for fully developed laminar flow in concentric annuli (Numerical Analysis). The Japan Society of Mechanical Engineers Transactions, 45, 227-239.
• [4] Nieckele, A. O., & Patankar, S. V. (1985). Laminar mixed convection in a concentric annulus with horizontal axis. Journal of heat transfer, 107(4), 902-909.
• [5] Habib, M. A., & Negm, A. A. A. (2001). Laminar mixed convection in horizontal concentric annuli with non-uniform circumferential heating. Heat and Mass Transfer/Waerme- Und Stoffuebertragung, 37(4–5), 427–435.
• [6] Muralidhar, K. (1989). Mixed convection flow in a saturated porous annulus. International Journal of Heat and Mass Transfer, 32(5), 881–888.
• [7] Nield, D. A., & Bejan, A. (2013). Convection in porous media. Convection in Porous Media 3rd edition, Springer, New York, 2006.
• [8] Vanover, D. E., & Kulacki, F. A. (1987). Experimental Study of Mixed Convection in a Horizontal Porous Annulus. ASME Heat Transfer Division, 84, 61–66.
• [9] Mohammed, H. A., Campo, A., & Saidur, R. (2010). Experimental study of forced and free convective heat transfer in the thermal entry region of horizontal concentric annuli. International Communications in Heat and Mass Transfer, 37(7), 739–747.
• [10] Ould-Amer, Y. (2010). Laminar mixed convection in horizontal concentric annuli with four porous blocks attached on the outside of the inner cylinder. ASME 10th Biennial Conference on Engineering Systems Design and Analysis (ESDA2010), July 12–14, 2010, Istanbul, Turkey, Paper no. ESDA2010-24077, 433-442.
• [11] Venugopal, G., Balaji, C., & Venkateshan, S. P. (2010). Experimental study of mixed convection heat transfer in a vertical duct filled with metallic porous structures. International Journal of Thermal Sciences, 49(2), 340–348.
• [12] Ould-Amer Y. (2013), “Optimal heat transfer in horizontal concentric annuli with the presence of porous structure,” International conference on mechanical engineering and technology, Amsterdam Nederland, 77, 486-494.
• [13] Ould-Amer Y. (2016). 3D Fully Developed Laminar Mixed Convection in Horizontal Concentric Annuli with the Presence of Porous Blocks. IACSIT International Journal of Engineering and Technology, Vol. 8, No. 2, 76-82.
• [14]Patankar, S. V. (1980). Numerical Heat Transfer and Fluid Flow. McGraw-Hill, New York, 1980.