International Scientific Journal


In this paper, entropy generation induced by natural convection of cu-water nanofluid in rectangular cavities with different circular corners and different aspect-ratios were numerically investigated. The governing equations were solved using a finite volume approach and the SIMPLE algorithm was used to couple the pressure and velocity fields. The results showed that the total entropy generation increased with the increase of Rayleigh number, irreversibility coefficient, aspect ratio or solid volume fraction while it decreased with the increase of the corner radius. It should be noted that the best way for minimizing entropy generation is decreasing Rayleigh number. This is the first priority for minimizing entropy generation. The other parameters such as radius, volume fraction, etc are placed on the second priority. However, Bejan number had an inverse trend compared with total entropy generation. As an exception, Bejan number and total entropy number had the same trend whenever solid volume fraction increased. Moreover, Nusselt number increased as Rayleigh number, solid volume fraction or aspect ratio increased whereas it decreases with the increase of corner radius.
PAPER REVISED: 2015-03-07
PAPER ACCEPTED: 2015-03-20
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THERMAL SCIENCE YEAR 2015, VOLUME 19, ISSUE Issue 5, PAGES [1621 - 1632]
  1. A. Bejan, A study of entropy generation in fundamental convective heat transfer, ASME J. Heat Transfer, 101 (1979), pp. 718-725.
  2. B.A.K. Abu-Hijleh, M. Abu-Qudais, E.Abu-Nada, Numerical prediction of entropy generation due to natural convection from a horizontal cylinder, Energy, 24, (1999), 4,pp. 327-333.
  3. I. Zahmatkesh, On the importance of thermal boundary conditions in heat transfer and entropy generation for natural convection inside a porous enclosure, Int.J.Therm.Sci., 47, (2008), 3, pp. 339- 346.
  4. D.C. Oliveski, M.H. Macagnan, J.B. Copetti, Entropy generation and natural convection in rectangular cavities, Applied Thermal Eng, 29 (2009), pp. 1417-1425.
  5. Mahmoud Salari, Abdola Rezvani, Ali Mohammadtabar and Mohammad Mohammadtabar, Numerical Study of Entropy Generation for Natural Convection in Rectangular Cavity with Circular Corners, Heat Transfer Engineering, 36(2014), 2, pp. 186-199.
  6. S.U.S. Choi, Enhancing Thermal Conductivity of Fluids with Nanoparticles, ASME 1995: Proc. Int. Mech. Eng. Cong. and Exposition, SanFrancisco, USA, (1995), pp. 99-105.
  7. K. Khanafer, K. Vafai and M.Lightstone , Buoyancy Driven Heat Transfer Enhancement in a Two-Dimensional Enclosure Utilizing Nanofluids ,Int. J. Heat Mass Trans., 46 (2001), pp. 3639 - 3653.
  8. Mahmoud Salari, Mohammad Mohammadtabar and Ali Mohammadtabar, Numerical solutions to heat transfer of nanofluid flow over stretching sheet subjected to variations of nanoparticle volume fraction and wall temperature, Applied Mathematics and Mechanics, 35(2014), 1, pp. 63-72
  9. B. Ghasemi, S. M. Aminossadati, Natural Convection Heat Transfer in an Inclined Enclosure Filled with a Water-Cuo Nanofluid, Num. Heat Tran., PartA: Applications, 55 (2009), pp. 807-823.
  10. A. H. Mahmoudi, M. Shahi, A. H. Raouf, and A. Ghasemian, Numerical Study of Natural Convection Cooling of Horizontal Heat Source Mounted in a Square Cavity Filled with Nanofluid, Int. Comm. Heat Mass Transfer, 37 (2010), pp. 1135-1141.
  11. Z. Alloui, P. Vasseur, and M. Reggio, Natural Convection of Nanofluids in a Shallow Cavity Heated from Below, Int. J.Therm.Sci., 50 (2011), pp.385-393.
  12. G. A. Sheikhzadeh, A. Arefmanesh, M. H. Kheirkhah, and R. Abdollahi, Natural Convection of Cu-Water Nanofluid in a Cavity with Partially Active Side Walls, Eur.J.Mech. B/Fluids 30 (2011) , pp.166-176.
  13. A. H. Mahmoudi, M. Shahi, and A. H. Raouf, Modeling of Conjugated Heat Transfer in a Thickwalled Enclosure Filled with Nanofluid, Int.Commu. Heat Mass Trans., 38 (2011), pp. 119-127.
  14. Y. Feng and C. Kleinstreuer, Nanofluid Convective Heat Transfer in a Parallel-Disk Sys-tem, Int .J. Heat Mass Trans. 53 (2010) 4619-4628.
  15. J. Li and C. Kleinstreuer, Entropy Generation Analysis for Nanofluid Flow in Microchannels, J. Heat Trans, 132 (2010), pp. 122401.1-122401.8.
  16. P. K. Singh, K. B. Anoop, T. Sundararajan, and S. K. Das, Entropy Generation Due to Flow and Heat Transfer in Nanofluids, Int .J. Heat Mass Transfer, 53 (2010), pp. 4757-4767.
  17. A. H. Mahmoudi, M. Shahi, and F. Talebi, Entropy Generation Due to Natural Convection in a Partially Open Cavity with a Thin Heat Source Subjected to a Nanofluid, Num. Heat Transfer, PartA, 61 (2012), pp. 283-305.
  18. Omid Mahian, Shohel Mahmud, Saeed Zeinali Heris," Analysis of Entropy Generation between Co-rotating Cylinders using Nanofluids", Energy, 2012
  19. Omid Mahian, Hakan F. Oztop, Ioan Pop, Shohel Mahmud, and Somchai Wongwises, " Design of a Vertical Annulus With MHD Flow Using Entropy Generation Analysis", Thermal Science, 2013.
  20. Fatih Selimefendigil, Hakan F. Oztop, " Effect Of An Adiabatic Fin On The Mixed Convection Heat Transfer In a Square Cavity With Two Ventilation Ports", Thermal Science, 2014.
  21. Omid Mahian, Ali Kianifar, Clement Kleinstreuer, Moh'd A. Al-Nimr, Ioan Pop, Ahmet Z. Sahin, Somchai Wongwises, A review of entropy generation in nanofluid flow, International Journal of Heat and Mass Transfer, 2013
  22. Mahmoud Salari, Mohammad Mohammad Tabar, Ali Mohammad Tabar and Hossein Ahmadi Danesh, Mixed Convection of Nanofluid Flows in a Square Lid-Driven Cavity Heated Partially From Both the Bottom and Side Walls, Num.Heat Transfer, Part A, 62 (2012), pp.158-177.
  23. Eiyad Abu-Nada and Ali J. Chamkha, Effect of nanofluid variable properties on natural convection in enclosures, International Journal of Thermal Science, 49 (2010), pp. 479-491.
  24. H. C. Brinkman, the Viscosity of Concentrated Suspensions and Solution, J. Chemical Physics 20 (1952), pp. 571-581.
  25. A. Bejan, Entropy generation through heat and fluid flow, Wiley, New York, 1982.
  26. Von S. V. Patankar, Numerical heat transfer and fluid flow, Hemisphere Publishing Corporation, Washington - New York - London. McGraw Hill Book Company, New York 1980.
  27. Eiyad Abu-Nada and Ali J. Chamkha, Mixed Convection Flow in a Lid-Driven Inclined Square Enclosure Filled with a Nanofluid, Eur.J.Mech.B/Fluids, 29 (2010), pp. 472-482.
  28. R. Iwatsu, J. Hyun and K. Kuwahara, Mixed Convection in a Driven Cavity with a Stable Vertical Temperature Gradient, Int. J. Heat Mass Trans., 36 (1993), pp. 1601-1608.
  29. K. Khanafer and A. J. Chamkha, Mixed Convection Flow in a Lid-Driven Enclosure Filled with a Fluid-Saturated Porous Medium, Int.J. Heat Mass Trans., 42 (1999), pp. 2465-2481.
  30. G. de Vahl Davis, Natural convection of air in a square cavity: a bench mark numerical solution, Int. J. Num. Methods Fluids, 3 (1983), pp. 249-264.
  31. M. Magherbi, H. Abbasi, A.B. Brahim, Entropy generation at the onset of natural convection, Int.J.Heat and Mass Trans., 46 (2003), pp. 3441-3450.
  32. Hakan F.Oztop, Eiyad Abu-Nada, Yasin Varol, Khaled Al-Salem, "Computational Analysis of Non-isothermal Temperature Distribution On Natural Convection In Nanofluid Filled Enclosures", ScienceDirect, Superlattices and Microstructures, Volume 49, Issue 4, April 2011, Pages 453-467.

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