Performance Analysis of Nature‐Inspired Branched Fins for Rapid Charging in Double‐Pipe Latent Heat Thermal Energy Storage Systems

ABSTRACT The low thermal conductivity of phase‐change materials (PCMs) hinders charging rates in double‐pipe latent heat thermal energy storage (LHTES) systems, which can be improved with fin assistance. To address the limitations of traditional straight fins, this study explores and analyses leaf‐like branched‐fin structures inspired by nature, with systematic parametric variation of branch numbers and angles to identify optimal configurations. This study numerically investigates a leaf‐like branched‐fin structure inspired by nature, comparing eight configurations: conventional designs with 4, 6, and 8 straight fins, and branched designs with 1, 2, and 3 branches at 35°, 45°, and 55°. A validated two‐dimensional numerical model employing an enthalpy–porosity approach in ANSYS Fluent is used to simulate melting behavior. Results indicate that branched‐fin designs outperform conventional ones. Case 8 (four main fins with three branches at 55°) achieves an average charging power of 3482.95 W, compared with 1773.40 W for the best conventional design (eight straight fins), reducing melting time by 50.3% (220 s vs. 443 s). Branched fins enhance heat transfer through combined conduction pathways and improved natural convection. These findings suggest that optimized branched‐fin geometries can accelerate PCM charging in LHTES systems under the conditions studied.