Research Article Effect of Magnetic Field on Mixed Convection Heat Transfer in a Lid-Driven Square Cavity N. A. Bakar, 1 A. Karimipour, 2 and R. Roslan 1 1 Centre for Research in Computational Mathematics, Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor, Malaysia 2 Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran Correspondence should be addressed to R. Roslan; rozaini@uthm.edu.my Received 8 October 2015; Revised 1 February 2016; Accepted 14 February 2016 Academic Editor: Pedro Jorge Martins Coelho Copyright © 2016 N. A. Bakar et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te efect of magnetic feld on fuid fow and heat transfer in two-dimensional square cavity is analyzed numerically. Te vertical walls are insulated; the top wall is maintained at cold temperature,   while the bottom wall is maintained at hot temperature,  ℎ where  ℎ >  . Te dimensionless governing equations are solved using fnite volume method and SIMPLE algorithm. Te streamlines and isotherm plots and the variation of Nusselt numbers on hot and cold walls are presented. 1. Introduction Due to the efect on many engineering applications and nature phenomena, fundamental problem of combined free and forced convection has received considerable attention from researchers. Problem of heat transfer in low speed lid- driven cavity is treated as a mixed convection problem. A forced convection conditions is created by the movement by one or two walls of the cavity while the temperature diference across the cavity caused a buoyancy driven fow. Hence, complicated heat and mass transfer fow occur inside the cavity. Tere have been many investigations in the past on mixed convection fow in lid-driven cavity. Many diferent confgurations and combinations of thermal boundary con- ditions have been considered by various investigators. One of the earliest investigations on mixed convection in lid-driven cavity was conducted by [1]. Later, [2] studied numerically the efect of the Prandtl (Pr) number, on the laminar mixed convection heat transfer in a lid-driven cavity. Te numerical simulations showed that, for higher values of Pr, the efect of thermal buoyancy force on the fow and heat transfer inside the cavity is more pronounced. Reference [3] investigated numerically mixed convection heat transfer in a driven cavity with a stable vertical temperature gradient. It was found that, for high values of the Richardson number, much of the fuid in both the middle and bottom portions of the cavity interior is stagnant. Also, results in [3] results showed that the fow features are similar to those of a conventional driven cavity of a nonstratifed fuid for small values of the Richardson number. Meanwhile, [4] carried out experimental study on mixed convection heat transfer and fuid fow in a cavity where the upper lid was cooled and heated from bottom. Reference [5] examined numerically mixed con- vection fow in a lid-driven enclosure flled with a fuid- saturated porous medium and reported on the efects of the Darcy and Richardson numbers on the fow and heat transfer characteristics. Reference [5] observed that the Darcy number is most important parameter in convective fows. Moreover, the presence of internal heat generation provides an additional dynamic in overall convective fow system, which has signifcant infuence on the features of isotherms and streamlines for small values of the Richardson number. Subsequently, various investigations on mixed convec- tion heat transfer in a lid-driven cavity are conducted. For instance, [6] investigated the mixed convection fuid fow and heat transfer in a square cavity with moving and diferentially heated side walls. Tey found that the fuid fow and heat transfer in the cavity are afected by both, Richardson number Hindawi Publishing Corporation Journal of ermodynamics Volume 2016, Article ID 3487182, 14 pages http://dx.doi.org/10.1155/2016/3487182