Contents lists available at ScienceDirect International Communications in Heat and Mass Transfer journal homepage: www.elsevier.com/locate/ichmt Entropy optimization and heat transfer modeling for Lorentz forces effect on solidification of NEPCM Zahir Shah a, ⁎ , Mohammed Reza Hajizadeh b,c , Ikramullah d , Nasser Aedh Alreshidi e , Wejdan Deebani f , Meshal Shutaywi f a Center of Excellence in Theoretical and Computational Science (TaCS-CoE), Science Laboratory Building, Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), 126 Pracha-Uthit Road, Bang Mod, Thrung Khru, Bangkok 10140, Thailand b Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam c The Faculty of Environmental and Chemical Engineering, Duy Tan University, Da Nang 550000, Vietnam d Department of Physics, Kohat University of Science & Technology, Kohat 26000, Khyber Pakhtunkhwa, Pakistan e Department of Mathematics, College of Science, Northern Border University, Arar 73222, Saudi Arabia f Department of Mathematics, College of Science & Arts, King Abdulaziz University, P.O. Box 344, Rabigh 21911, Saudi Arabia ARTICLEINFO Keywords: CuO nanoparticles Entropy generation PCM, NEPCM (nano enhanced phase change material) LHTESS, FEM Bejan number (Be) ABSTRACT In this research work, we study the solidification of nanoparticles-enhanced phase change material (NEPCM) in a latent heat thermal energy storage system (LHTESS) in the existence of magnetic field through entropy opti- mization. The Finite element method (FEM) is applied for solving the developed equations. Koo–Kleinstreuer–Li model is used to model the nanoparticles characteristics. The impacts of varying strength of magnetic field and buoyancy forces on solidification are examined. It is obtained that the rising Lorentz force due to augmenting Hartmann number enhances the solidification rate of NEPCM, while the enhancing buoyancy forces mitigates this rate of solidification. The Bejan number (Be) augments with the higher Lorentz forces while drops with the augmenting Buoyancy forces. The entropy generations due to the frictional forces and the applied B-field augment with the rising buoyancy forces while depreciate with the rising Hartmann number. The agreement between our and already published work confirms the accuracy of the applied computational technique. The results of this research work have potential applications in modeling the efficient thermal energy transfer sys- tems by using nanofluids. 1. Introduction In large scale industrial systems, like combustion chambers, heavy machines, and other electric and electronic systems, the production of heat causes to reduce the efficiency of a system. To handle such si- tuations and make the system more efficient, the heat produced during system operation must be removed. In recent years, the use of nano- particles due to their high thermal conductivities has played a pivotal role in order to remove the heat produced more rapidly and efficiently as compared to the conventional fluids. Nanoparticles are nanometer- size particles, mostly made of metals and metals oxide. It has been proved that the dimensions and shapes of these particles have central importance role in the phenomena of heat transfer. The uses of nano- particles have now been expanded to medical sciences, where it is used for killing the infected cells, especially in the treatment of cancer and tumor cells. The thermal characteristics and exciting applications of nanolfuids are described in 1-3]. Oudina [4] studied the flow of Titania nanofluid through a cylindrical container by considering different base fluids and a discrete heat energy source. He also numerically examined the convective heat transformation with MHD nanofluid using various geometries [5]. Sheikholeslami et al. [6] examined the Lorentz forces impact on the thermal characteristics of nanofluid through a permeable container having elliptical shape obstacle. Dat et al. examined nu- merically the nanomaterial flow through a sinusoidal permeable cavity [7]. Chaim [8] for the first time studied the fluid flow with heat energy transfer and varying thermal conduction on a stretching sheet. The problem of heat transmission between deformable permeable channels hasbeenanalyzedbyAsgharetal.[9] through analytical and numerical solutions. The recent research work about heat transfer through dif- ferent nanofluids and its various applications can be consulted in the . [10–14]. Shah et al. [15–17] worked on the nanofluid motion through different geometries by taking into account electric, magnetic and Hall https://doi.org/10.1016/j.icheatmasstransfer.2020.104715 ⁎ Corresponding author. E-mail address: zahir.sha@kmutt.ac.th (Z. Shah). International Communications in Heat and Mass Transfer 117 (2020) 104715 0735-1933/ © 2020 Elsevier Ltd. All rights reserved. T