The aim of this study is to assess the convective heat transfer and flow characteristics surrounding a heated sphere and a sphere filled with phase change material (PCM). A numerical simulation is conducted whereby a stationary copper sphere is positioned within a cylindrical channel, maintaining a constant ratio of channel diameter to sphere diameter of 1.43. A numerical simulation is conducted to analyse the transient flow in a three-dimensional setting using the ANSYS-F: UENT software. The simulation involves solving the K-epsilon model. Within the specified range of Reynolds numbers (4000–15000), the numerical outcomes pertaining to the average surface temperature and heat transfer coefficient exhibit a satisfactory level of concurrence with the findings reported in prior scholarly works. The heat transfer coefficient distribution, temperature profiles, and velocity fields surrounding a solid sphere and a sphere filled with phase change materials (PCMs) are computed and examined.