Influence of Double Fin Shape on Constrained Melting of PCM in a Spherical Capsule: A Numerical Study

The current study numerically investigates the effect of double fin shape on the constrained melting of PCM in a spherical capsule. The fins are symmetrically spaced from the centre. To ensure that the results are comparable, the base and area of each fin are kept constant across all cases. Straight, trapezoidal converging, stepped, and triangular fin shapes are considered for the analysis. Current numerical results for liquid fraction are being compared with the experimental findings of Fan et al. (Appl Therm Eng 100:1063–1075, 2016) and showed good agreement. Melt fraction, average velocity, and fin effectiveness is being compared for all the cases. Melting time of PCM decreases significantly with the presence of fin. Total time for melting of PCM is nearly the same for stepped and trapezoidal converging fin cases because the surface area to volume ratio (S/V) is similar for both. The triangular fin case has the shortest PCM melting time of 95 min, while the rectangular fin case has the longest melting time of 116 min. The present work could be used for the optimization of LHTES unit integrated with fins in industries.