CFD-Based Multi-Objective Optimization of Straight-Fin Thermal Energy Storage Using MXene/BNNT–Erythritol Composite System

Abstract. The research used CFD to study the system while performing multi-objective optimization on a rectangular LHTES unit containing bio-based erythritol and MXene/BNNT composite fin enhancements. The enthalpy–porosity method was used to simulate melting behavior and a finite-volume solver handled both natural convection and phase change processes. The Design of Experiments–Response Surface Methodology (DOE–RSM) framework optimized fin number, thickness, and span to achieve both fast charging and high storage capacity. The three-fin design configuration shortens total melting time by 60% while increasing stored energy to twice the level of the finless design. The research shows MXene/BNNT composites create better heat transfer paths which maintain their ability to store heat thus enabling developers to create efficient TES modules for solar and waste-heat recovery systems.