Investigation of Fractal Fins towards Heat Transfer Properties in Thermal Storage System

To augment heat transfer in energy storage systems, fin inclusion is frequently adopted. This study critically examines various fin arrangements by employing a dimensionless parameter calculation method. Metrics of comparison include total melting time, dynamic temperature behavior, liquid fraction, and a unit performance indicator. The findings reveal that at Prandtl and Stefan numbers of unity, a Rayleigh number of 104 demarcates the boundary between convective and conductive heat transfer, thus determining the dominant heat transfer mode. By reorienting the internal fins within a four-fin structure, we observed improved transfer performance at low Rayleigh numbers (Ra ≤ 104); the liquid fraction approached unity with rising Rayleigh numbers. When assessing the unit performance metric, the reoriented four-fin structure manifested superior attributes in comparison to alternative configurations for Ra ≤ 5 × 104. However, at higher Rayleigh numbers, complex fin structures impede heat convection, and the two-fin structure makes the more effective configuration.