Chavan, S.Gumtapure, V.Arumuga Perumal, D.2026-02-052021Computational Thermal Sciences, 2021, 13, 1, pp. 55-7119402503https://doi.org/10.1615/ComputThermalScien.2020033738https://idr.nitk.ac.in/handle/123456789/23477The present work is an attempt to understand the effect of geometry on the heating and cooling characteristics of thermal energy storage systems. Three different geometrical models (square, pentagon, and hexagon) were considered and the thermal storage material used was a composite of paraffin wax (98%) and Al<inf>2</inf>O<inf>3</inf> nanoparticles (2%). The heating and cooling processes were analyzed by applying a constant heat flux. Among the three models, the square model showed a faster melting rate but the cooling rate was too steep. The hexagonal model showed optimum results in both the heating and cooling processes with uniform and smooth variations in the liquid fraction and temperature. Hence, for optimal thermal storage applications the hexagonal model (or its geometries), which is close to the circular model, can be considered. © 2021 by Begell House, Inc.AluminaAluminum oxideCoolingCooling systemsHeat fluxHeat storageStorage (materials)Thermal energyComputational investigationConstant heat fluxGeometrical modelsHeating and coolingLiquid fractionMelting ratesThermal energy storage systemsThermal storageGeometry