Application of the field synergy principle in rotating thermal energy storage systems: A multi-objective comprehensive evaluation of fin performance

This study pioneers the application of the Field Synergy Principle (FSP) to evaluate and optimize fin configurations in rotating thermal energy storage systems (TESS) using phase change materials (PCM). Through numerical simulations and the Entropy Weighted TOPSIS Method (EWTM), five fin designs—Arc, T-shaped, Straight, Y-shaped, and Arrow were systematically analyzed. This study uniquely combines FSP with multi-objective optimization to identify configurations that can not only enhance heat transfer efficiency but also address critical engineering constraints. Results demonstrate that the Arc and T-shaped fins significantly enhance heat transfer efficiency and reduce PCM melting time. Specifically, the Arc fin reduced melting time by 32.2 % (484.1 s vs. 714.1 s for Straight fin), attributed to a lower synergy angle ( θ ) of 50°–55° (vs. 70°–75° for Straight fin), indicating superior alignment between velocity and temperature gradients. While the Arc fin exhibited the fastest melting, the T-shaped fin emerged as the optimal configuration in the EWTM multi-objective evaluation, balancing heat transfer efficiency (29.60 W energy storage rate), lightweight design (459.98 mm 2 fin area), and economic viability. The T-shaped fin's synergy angle dynamics and 26.1 % melting time reduction (527.9 s) highlight its potential to address low PCM thermal conductivity challenges. This work advances fin design strategies for rotating TESS, offering critical insights for applications in renewable energy storage, industrial waste heat recovery, and electric vehicle thermal management.