Amirkabir University of TechnologyAUT Journal of Mechanical Engineering2588-29376320220901A Parametric Investigation of Melting Process within a Porous Medium under Local Thermal Non-Equilibrium Condition Using Lattice Boltzmann Method467488483310.22060/ajme.2022.20383.5997ENMohammadTaghilouDepartment of Engineering, University of Zanjan, Zanjan, IranSeyed AlirezaSafaviDepartment of Engineering, University of Zanjan, Zanjan, IranJournal Article20210807The use of a porous medium with a high conductivity improves the rate of heat transfer in latent energy storage systems. This paper investigates the melting of the phase change material inside a porous medium under the local thermal non-equilibrium condition with the lattice Boltzmann method. Results examine the effect of Rayleigh number, porosity ratio, pore size, and Sparrow number on the liquid fraction and position of the melting front. Results show that by increasing the pore diameter, the interface of the two phases tends to bend but the liquid fraction decreases. Also, it is found that the difference between the liquid fraction in the presence and absence of natural convection for <em>Ra</em><10<sup>6</sup>, is less than 5%. Nonetheless, by increasing the Rayleigh number to 10<sup>8</sup>, this difference at <em>Fo</em>=0.003 is more than 14% and at <em>Fo</em>=0.006 will reach more than 31%. Furthermore, in <em>Ra</em>=10<sup>8</sup> and for small Sparrow numbers, this difference is small and intensifies with increasing the Sparrow number. Also, by reducing the Darcy number, natural convection is weakened and it can be ignored for <em>Da</em><10<sup>-4</sup>. It is shown that in small Darcy numbers <em>Da</em>=10<sup>-4</sup>, the deviation from the pure conduction is always increased by Sparrow number, and for larger Darcy numbers <em>Da</em>=10<sup>-2</sup>, this deviation has a maximum value of 53% at <em>Fo</em>=0.003 and 84% at <em>Fo</em>=0.006.https://ajme.aut.ac.ir/article_4833_aef7b392fc15163377f2881b48baabb3.pdf