A numerical simulation using the commercial software “COMSOL Multiphysics” was carried out to study the flow around two fixed spheres filled with a phase-change material (PCM). This work focuses essentially on the process of fusion of the two interactive spheres located at different distances and on the heat exchange with the air flowing around two capsules. Two dispositions were examined: the first for two aligned capsules, while the second for two nonaligned ones. The separation distance d between the two capsules ranged from 2R to 8R. The influence of the inter-capsule distance on the thermal behavior of the system was demonstrated. The results show that the interaction rate between the capsules decreases as a function of the separation distance and that there is an optimum distance d from which each capsule behaves independently of the other. This distance is equal to d=6R for the first case and d=3R for the second case. It was noted that the local exchange coefficients’ variation on the surfaces was influenced by the effect of the distance between the two capsules.