عنوان مقاله [English]
Weight loss, dimensions, and energy consumption are important issues in the aerospace industry (spacecraft and space station), which requires a high capacity cooling system and smaller dimensions. Nanofluids can play an important role in cooling systems. In this paper, natural convection of water-alumina nanofluid in a square cavity with a thin partition mounted at the middle of the cavity is studied. The cavity has different orientation angles with respect to the horizon. For the horizontal cavity, the top and bottom walls are adiabatic and the left and the right walls are considered to be hot and cold, respectively. At the center of cavity, a vertical baffle with negligible thickness is mounted. The nanofluid inside the cavity is under a magnetic field. Governing equations were discretized through control volume approach and were solved simultaneously applying SIMPLER algorithm. Based on obtained results from numerical method, the influence of pertinent parameters such as the orientation angle of the cavity, Rayleigh number, the volume fraction of nanoparticles and Hartman number on the flow field and heat transfer are investigated. The results show that maximum heat transfer occurs when the angle of hot wall with respect to the horizon is 45. Also, the existence of the baffle and increase of Hartman number reduce the heat transfer while the increase of Rayleigh number enhances the transfer of heat. Depending on Rayleigh number, the increase of nanoparticle volume fraction may increase or decrease the thermal performance.
 S. Sadeghi, B. Ghasemi, Mixed Convection Heat Transfer of Nanofluids in an Inclined Channel Under Magnetic Field, Modares Mechanical Engineering, Vol. 13, No. 7, pp. 18-31, 2018 (in Persian)
 G. Kefayati, M. Gorji, H. Sajjadi, D. D. Ganji, Investigation of Prandtl number effect on natural convection MHD in an open cavity by Lattice Boltzmann Method, Engineering Computations, Vol. 30, No. 1, pp. 97-116, 2012.
 Y. Li, J. Zhou, S.Tung, E. Schneider E, S. Xi, A review on development of nanofluid preparation and characterization, Journal of Powder Technology, Vol. 196, No. 2, pp. 89-101, 2009
 A. Shahriari, Effect of magnetic field on natural convection heat transfer of nanofluid in wavy cavity with non-uniform temperature distribution, Modares MechanicalEngineering, Vol. 17, No. 4, pp. 29-40, 2017. (in Persian)
 M. Raihani, A. Abedin, A. Ebrahimi, Study the Properties of Performance and Sustainability of Nanofluids and ferrofluids, Journal of ISME, , Vol. 26, No. 116, pp. 51-65, 2017 (in Persian).
 H. Fazeli, P. Rahim mashaei, M. Shahryari, S. Madan, Investigation & simulation of Nanoparticle application in satellite equipment cooling; simultaneous use of Nano fluid and a heat pipe with three evaporators, Journal of Aerospace Knowledge and Technology, Vol. 6, No. 2, pp. 41-54 Summer 2017. (in Persian)
 Z. H. Liu, Y. Y. Li, A new frontier of nanofluid research-application of nanofluids in heat pipes, International Journal of Heat and Mass Transfer, Vol. 55, pp. 6786-6797, 2012.
 T. Saitoh, K. Hirose, High-accuracy benchmark solutions to natural convection in a square cavity, Journal of Computational Mechanics, Vol. 13, No. 4, pp.417-427, 1989.
 G. De Vahl Davis, Natural convection of air in a square cavity :a Benchmark solution, International Journal for numerical methods in fluids, Vol. 3, No. 3, pp. 249-264, 1983.
 Q. H. Deng, G. F. Tang, Y. A. Li, combined temperature scale for analyzing natural convection in rectangular enclosures with discrete wall heat sources, International Journal of Heat and Mass Transfer, Vol. 45, No. 16, pp.3437-3446, 2002.
 H. F. Oztop, E. Abu-Nada, Numerical study of natural convection in partially heated rectangular enclosures filled with nanofluids, International journal of heat and fluid flow, Vol. 29, No. 5, pp. 1326–1336, 2008.
 M.S. Krakov, I.V. Nikiforov, To the inﬂuence of uniform magnetic ﬁeld on thermomagnetic convection in square cavity, Journal of Magnetism and Magnetic Materials, Vol. 252, pp. 209–211, 2002.
 T. Jue, Analysis of combined thermal and magnetic convection ferroﬂuid ﬂow in a cavity, International communications in heat and mass transfer, Vol. 33, No. 7, pp. 846–852, 2006.
 H. L. G. Couto, N. B. Marcelino, F. R. Cunha, A study on magnetic convection in a narrow rectangular cavity, Journalof Magnetohydrodynamics, Vol 43, No. 4, pp. 421-428, 2007.
 N. C. Markatos, K. A. Pericleous, Laminar and turbulent natural convection in an enclosed cavity, International Journal of Heat and Mass Transfer, Vol. 27, No. 5, pp. 772-775, 1984.
 M. A. Teamah, Numerical simulation of double diffusive natural convection in rectangular enclosure in the presences of magnetic field and heat source, International Journal of Thermal Sciences, Vol. 47, No.3, pp. 237-248, 2008.
 S. Sivasankaran, C. J. Ho, Effect of temperature dependent properties on MHD convection of water near its density maximum in a square cavity, International Journal of Thermal Sciences, Vol. 47, No. 9, pp. 1184-1194, 2008.
 B. Ghasemi, S.M. Aminossadati, A. Raisi, Magnetic field effect on natural convection in a nanofluid-filled square enclosure, International Journal ofThermal Sciences, Vol. 50, No. 9, pp. 1748-1756, 2011.
 M. Pirmohammadi, M. Ghassemi, Effect of magnetic field on convection heat transfer inside a tilted square enclosur, International Communications in Heat and Mass Transfer, Vol. 36, No. 7, pp. 776–780, 2009.