NUMERICAL INVESTIGATION OF BUOYANCY DRIVEN HEAT TRANSFER OF WATER-BASED CuO NANOFLUIDS IN A RECTANGULAR ENCLOSURE WITH AN OFFCENTER SOLID CONDUCTING BODY

Abstract

In this study, buoyancy driven heat transfer of water-based CuO nanofluid in a rectangular enclosure with a solid cylinder was investigated numerically for different values of aspect ratio, location and diameter of solid cylinder, solid volume fraction and Rayleigh number. While bottom and upper walls of enclosure are adiabatic, sidewalls are isothermal. Thermal conductivity of solid cylinder was assumed to be equal to that of the base fluid. Governing equations were solved numerically by Comsol Multiphysics finite element modeling and simulation software. Results show that heat transfer rate increases considerably with an increase in the Rayleigh number and solid volume fraction and with a decrease in the solid cylinder diameter. Results also show that heat transfer rate shows an increase with an increase of aspect ratio for low values of Rayleigh number. Finally, results show that heat transfer rate gets its highest value for square enclosure case for high values of Rayleigh number.

Keywords

• Nanofluid,Enclosure

References

1. Brinkman H. C., 1952, The Viscosity of Concentrated Suspensions and Solutions, J. Chem. Phys., 20, 571-581.
2. Choi S. U. S., Zhang Z. G., Yu W., Lockwood F. E. and Grulke E. A., 2001, Anomalous Thermal Conductivity Enhancement in Nanotube Suspensions, Appl. Phys. Lett., 79(14), 2252–2254.
3. Cianfrini M., Corcione M. and Quintino A., 2011, Natural Convection Heat Transfer of Nanofluids in Annular Spaces Between Horizontal Concentric Cylinders, Appl. Therm. Eng., 31(17-18), 4055–4063.
4. Cihan A., Kahveci K. and Susantez Ç., 2012, Buoyancy Driven Heat Transfer of Water-Based CuO Nanofluids in a Tilted Enclosure with a Heat Conducting Solid Cylinder on Its Center, World Congress on Engineering, London, 1750-1754.
5. Hamilton R. L., and Crosser O. K., 1962, Thermal Conductivity of Heterogeneous Two-Component Systems, Ind. Eng. Chem. Fundam., 1(3), 187–191.
6. Jang S. P. and Choi S. U. S., 2004, Role of Brownian Motion in the Enhanced Thermal Conductivity of Nanofluids, Appl. Phys. Lett., 84(21), 4316–4318.
7. Kahveci K., 2010, Buoyancy Driven Heat Transfer of Nanofluids in a Tilted Enclosure, J. Heat Transfer, 132(6), 062501.
8. Kang H. U., Kim S. H. and Oh J. M., 2006, Estimation of Thermal Conductivity of Nanofluid Using Experimental Effective Particle Volume, Exp. Heat Transfer, 19(3), 181–191.

9. Khanafer K., Vafai K. and Lightstone M., 2003, Buoyancy-driven heat transfer enhancement in a two-dimensional enclosure utilizing nanofluids, Int. J. Heat Mass Tran., 46, 3639-3653.
10. Lai F. H. and Yang Y. T., 2011, Lattice Boltzmann Simulation of Natural Convection Heat Transfer of Al2O3/water Nanofluids in a Square Enclosure, Int. J. Therm. Sci., 50(10), 1930–1941.
11. Li C. H. and Peterson G. P., 2006, Experimental Investigation of Temperature and Volume Fraction Variations on the Effective Thermal Conductivity of Nanoparticle Suspensions (Nanofluids), J. Appl. Phys., 99(8), 084314.
12. Maxwell J. C., 1873, A Treatise on Electricity and Magnetism (Vol.II), Clarendon Press, Oxford, 54.
13. Murshed S. M. S., Leong K.C. and Yang C., 2008, Investigations of Thermal Conductivity and Viscosity of Nanofluids, Int. J. Therm. Sci., 47(5), 560–568.
14. Murshed S. M. S., Leong K.C. and Yang C., 2009, A Combined Model for the Effective Thermal Conductivity of Nanofluids, Appl. Therm. Eng., 29(11-12), 2477–2483.
15. Oztop H. F. and Abu-Nada E., 2008, Numerical Study of Natural Convection in Partially Heated Rectangular Enclosures Filled with Nanofluids, Int. J. Heat Fluid Flow, 29(5), 1326–1336.
16. Pak B.C. and Cho Y. I., 1998, Hydrodynamic and Heat Transfer Study of Dispersed Fluids with Submicron Metallic Oxide Particles, Exp. Heat Transfer, 11(2), 151–170.
17. Rahman M. M., Billah M. M., Rahman A. T. M. M., Kalam M. A., Ahsan A., 2011, Numerical Investigation of Heat Transfer Enhancement of Nanofluids in an Inclined Lid-Driven Triangular Enclosure, Int. Commun. Heat Mass Transfer, 38(10), 1360–1367.
18. Susantez Ç., Kahveci K., Cihan A. and Hacihafızoğlu O. 2012, Natural Convection of Water-Based CuO Nanofluids in an Enclosure with a Heat Conducting Solid Circular Cylinder at the Center. 6th International Ege Energy Symposium & Exhibition, İzmir, 653-664.
19. Wang X., Xu X. and Choi S. U. S., 1999, Thermal Conductivity of Nanoparticle–Fluid Mixture, J. Thermophys Heat Transfer, 13(4), 474–480.
20. Wong K. V. and Leon O., 2010, Applications of Nanofluids: Current and Future (Review Article), Advances in Mechanical Engineering, 2, 1-11.
21. Xuan Y. and Li Q., 2000, Heat Transfer Enhancement of Nanofuids, Int. J. Heat Fluid Flow, 21(1), 58–64.
22. Xuan Y. and Li Q., 2003, Investigation on Convective Heat Transfer and Flow Features of Nanofluids, J. Heat Transfer, 125(1), 151–155.
23. Yu W., and Choi S. U. S., 2003, The Role of Interfacial Layers in the Enhanced Thermal Conductivity of Nanofluids: A Renovated Maxwell Model, J. Nanopart. Res., 5(1), 167–171.
24. Yu Z. T., Xu X., Hu Y. C., Fan L. W. and Cen K. F., 2011, Numerical Study of Transient Buoyancy-Driven Convective Heat Transfer of Water-Based Nanofluids in a Bottom-Heated Isosceles Triangular Enclosure, Int. J. Heat Mass Transfer, 54(1-3), 526–532.