Document Type : Research Paper


Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran


In this study, cooling of a hot obstacle in a rectangular cavity filled with water-CuO nanolfuid has been examined numerically. This cavity has an inlet and outlet and the cold nanofuid comes from the left side of the cavity and after cooling the hot obstacle, it goes out from the opposite site. All of the walls are insulated, and the SIMPLER algorithm has been employed for solving the governing equations. The effects of fluid inertia, magnetic field strength, volume fraction of nanoparticles, and the place of outlet on heat transfer rate has been scrutinized. According to the results, the average Nusselt number builds up as the outlet place goes down. In other words, when the outlet is located at the bottom of the cavity, the rate of the heat transfer is maximum. Moreover, by increasing the Reynolds number and volume fraction of nanoparticles, the average Nusselt number builds up as well.

Graphical Abstract

Cooling a hot obstacle in a rectangular enclosure by using a MHD nanofluid with variable properties


Main Subjects

[1]  M. Abbaszadeh, A. Ababaei, A. A. A. Arani, and A. A. Sharifabadi, "MHD forced convection and entropy generation of CuO-water nanofluid in a microchannel considering slip velocity and temperature jump," Journal of the Brazilian Society of Mechanical Sciences and Engineering, Vol. 39, No. 3, pp. 775–790, (2017).

[2]  A. Aghaei, H. Khorasanizadeh, G. a. Sheikhzadeh, and M. Abbaszadeh, "Numerical study of magnetic field on mixed convection and entropy generation of nanofluid in a trapezoidal enclosure," Journal of Magnetism and Magnetic Materials, Vol. 403, pp. 133-145, (2016).

[3]  A. R. Rahmati, A. R. Roknabadi, and M. Abbaszadeh, "Numerical simulation of mixed convection heat transfer of nanofluid in a double lid-driven cavity using lattice Boltzmann method," Alexandria Engineering Journal, Vol. 55, No. 4, pp. 3101-3114, (2016).

[4]  M. Mollamahdi, M. Abbaszadeh, and G. A. Sheikhzadeh, "Flow field and heat transfer in a channel with a permeable wall filled with Al2O3-Cu/water micropolar hybrid nanofluid, effects of chemical reaction and magnetic field," Journal of Heat and Mass Transfer Research (JHMTR), Vol. 3, No. 2, pp. 101-114, (2016).

[5]  G. Sheikhzadeh, H. Ghasemi, and M. Abbaszadeh, "Investigation of natural convection boundary layer heat and mass transfer of MHD water-AL2O3 nanofluid in a porous medium," International Journal of Nano Studies & Technology (IJNST), Vol. 5, No. 2, pp. 110-122, (2016).

[6]  G. Sheikhzadeh, A. Aghaei, H. Ehteram, and M. Abbaszadeh, "Analytical study of parameters affecting entropy generation of nanofluid turbulent flow in channel and micro-channel," Thermal Science, (2016).

[7] A. Abbasian Arani, J. Amani, and M. Hemmat Esfeh, "Numerical simulation of mixed convection flows in a square double lid-driven cavity partially heated using nanofluid," Journal of Nanostructures, Vol. 2, No. 3, pp. 301-311, (2012).

[8] A. Ababaei, M. Abbaszadeh, A. Arefmanesh, and A. J. J. N. H. T. Chamkha, Part A: Applications, "Numerical simulation of double-diffusive mixed convection and entropy generation in a lid-driven trapezoidal enclosure with a heat source," pp. 1-19, (2018).

[9]  A. Ababaei and M. J. G. J. o. N. Abbaszadeh, "Second Law Analyses of Forced Convection of Low-Reynolds-Number Slip Flow of Nanofluid Inside a Microchannel with Square Impediments," Vol. 1, No. 4, (2017).

[10] K. Khanafer, K. J. I. j. o. h. Vafai, and m. transfer, "A critical synthesis of thermophysical characteristics of nanofluids," Vol. 54, No. 19-20, pp. 4410-4428, (2011).

[11] I. Hashim, A. Alsabery, M. Sheremet, and A. J. A. P. T. Chamkha, "Numerical investigation of natural convection of Al2O3-water nanofluid in a wavy cavity with conductive inner block using Buongiorno’s two-phase model," (2018).

[12] A. Arefmanesh, A. Aghaei, and H. Ehteram, "Mixed convection heat transfer in a CuO–water filled trapezoidal enclosure, effects of various constant and variable properties of the nanofluid," Applied Mathematical Modelling, Vol. 40, No. 2, pp. 815-831, (2016).

[13] H. Brinkman, "The viscosity of concentrated suspensions and solutions," The Journal of Chemical Physics, Vol. 20, No. 4, pp. 571-571, (1952).

[14] J. Maxwell Garnett, "Colours in metal glasses and in metallic films, Philos. Tr. R. Soc. S.-A, 203, 385–420," ed, (1904).

[15] J. Koo and C. Kleinstreuer, "A new thermal conductivity model for nanofluids," Journal of Nanoparticle Research, Vol. 6, No. 6, pp. 577-588, (2004).

[16] H. Xu, Z. Wang, F. Karimi, M. Yang, and Y. Zhang, "Numerical simulation of double diffusive mixed convection in an open enclosure with different cylinder locations," International Communications in Heat and Mass Transfer,Vol. 52, pp. 33-45, (2014).