Natural convection of Al2O3-water nanofluid with variable properties in a square enclosure with heat source and heat sink on the vertical walls

Document Type : Research Paper

Authors

Azad University of Badrood

Abstract

The buoyancy-driven fluid flow and heat transfer in a square cavity with partially active side walls filled The buoyancy-driven fluid flow and heat transfer in a square cavity with partially active side walls filled which the length is equal to half of height and width is 0.1 of height respectively so that it contains Al_2 O_3–water nanofluid which variable properties, has been investigated numerically. The active parts of the left and the right side walls of the cavity are maintained at temperatures Th and Tc , respectively, with Th>Tc . The enclosure’s top and bottom walls as well as the inactive parts of its side walls are kept insulated. The governing equations in the two-dimensional space are discretized using the control volume method. A proper upwinding scheme is employed to obtain stabilized solutions. Using the developed code, a parametric study is undertaken, and the effects of the Rayleigh number, the locations of the active parts of the side walls and the volume fraction of the nanoparticles on the fluid flow and heat transfer inside the cavity are investigated. It is observed from the results that the average Nusselt number increase with increasing the Rayleigh number and decrease with increasing the volume fraction of the nanoparticles. Moreover, the maximum average Nusselt number for the high and the low Rayleigh numbers occur for the bottom–middle locations of the thermally active parts, respectively.

Keywords

References

[1]      Choi, U.S. (1995). “Enhancing thermal conductivity of fluids with nanoparticles”. ASME Fluids Eng, Div. 231, pp. 99–105.
[2]      Xie, H.Q., Wang, J.C., Xi, T.G., Li, Y., Ai, F. (2002). “Dependence of the thermal conductivity of nanoparticle–fluid mixture on the base fluid”. J. Mater. Sci, Lett. 21, pp. 1469–147.
[3]      Khanafer, K., Vafai, K., Lightstone, M. (2003). “Buoyancy-driven heat transfer enhancement in a two-dimensional enclosure utilizing nanofluids”. Int. J. Heat Mass Transfer, Vol. 46, pp. 3639–3653.
[4]      Jou, R.Y., Tzeng, S.C. (2006). “Numerical research of nature convective heat transfer enhancement filled with nanofluids in rectangular enclosures”. Int. Commun. Heat Mass Transfer, Vol. 33, pp. 727–736.
[5]      Polidori, G., Fohanno, S., Nguyen, C.T. (2007).  “A note on heat transfer modeling of Newtonian nanofluids in laminar free convection”. Int. J. Therm. Sci, Vol. 46, pp. 739–744.
[6]      Valencia, A., Frederick, R.L. (1998). “Heat transfer in square cavities with partially active vertical walls”. Int. J. Heat Mass Transfer, Vol. 32, pp. 1567–1574.
[7]      Deng, Q.H., Tang, G.F., Li, Y. (2002). “A combined temperature scale for analyzing natural convection in rectangular enclosures with discrete wall heat sources”. Int. J. Heat Mass Transfer, Vol. 45, pp. 3437–3446.
[8]      Nithyadevi, N., Kandaswamy, P., Lee, J. (2007). “Natural convection in a rectangular cavity with partially active side walls”. Int. J. Heat Mass Transfer, Vol. 50, pp. 4688–4697.
[9]      Oztop, H.F., Abu-Nada, E. (2008). “Numerical study of natural convection in partially heated rectangular enclosures filled with nanofluids”. Int. J. Heat Fluid Flow, Vol. 29, pp. 1326–1336.
[10]      Sheikhzadeh, G.A., Arefmanesh, A., Kheirkhah, M.H., Abdollahi, R. (2011). “Natural convection of Cu–water nanofluid in a cavity with partially active side walls”. European Journal of Mechanics B/Fluids, Vol. 30, pp. 166–176.
[11]      Corcione, M. (2011). “Empirical correlating equations for predicting the effective thermal conductivity and dynamic viscosity of nanofluids”. Energy Conversion and Management, Vol. 52, pp. 789–793.
[12]      Bijan, A. (1984). “Convection heat transfer”, third edition, Wily, NewYork.
[13]      Alloui, Z., Vasseur, P., Reggio, M. (2010). “Natural convection of nanofluids in a shallow cavity heated from below". International Journal of Thermal Sciences, Vol. 50, pp. 1-9.
[14]      Barakos, G., Mitsoulis, E. (1994). “Natural convection flow in a square cavity revisited, laminar and turbulent models with wall functions”. Internat. J. Numer. Methods Fluids, Vol. 18, pp. 695–719.
[15]      Markatos, N.C., Pericleous, K.A. (1984). “Laminar and turbulent natural convection in an enclosed cavity”. Int. J. Heat Mass Transfer, Vol. 27, pp. 772–775.
[16]      De Vahl Davis, G. (1983). “Natural convection of air in a square cavity, a benchmark numerical solution”. Internat. J. Numer. Methods Fluids, Vol.3, pp. 249–264.
[17]      Fusegi, T., Hyun, J.M., Kuwahara, K., Farouk, B. (1991). “A numerical study of three dimensional natural convection in a differentially heated cubical enclosure”. Int. J. Heat Mass Transfer, Vol. 34, pp. 1543–1557.
[18]      Aminossadati, S.M., Ghasemi, B. (2011). “Natural convection of water–CuO nanofluid in a cavity with two pairs of heat source–sink”. International Communications in Heat and Mass Transfer, Vol. 38, pp. 672–678.
[19]      Abu-Nada, E., Chamkha, A.J. (2010). “Effect of nano fluid variable properties on natural convection in enclosures filled with a CuO-EG-Water nanofluid”, International Journal of Thermal Sciences, Vol. 49, pp. 2339-2352.
[20]      Abu-Nada, E. (2010). “Effect of nano fluid variable properties on natural convection in enclosures filled with a CuO-EG-Water nanofluid”, International Journal of Heat and Fluid Flow, Vol. 30, pp. 679-690.
 
Journal of Modeling in Engineering
Volume 15, Issue 49
September 2017
Pages 1-16

Files

History

  • Receive Date: 06 August 2013
  • Revise Date: 05 April 2015
  • Accept Date: 13 May 2015

Share

How to cite

Statistics