NUMERICAL STUDY OF THERMAL MANAGEMENT FOR A CYLINDRICAL HEAT SOURCE BY PCM COMBINED WITH ANNULAR FINS

In the study, annular fins are used to improve the thermal management performance of the phase change material (PCM) towards a cylindrical heat source. A two-dimensional axisymmetric model is established and the influence of fins on the temperature of the heat source is studied in conjunction with the melting process of PCM. The effects of the positions of a single annular fin are investigated. Results show that the lower the individual fin is in the PCM, the faster the melting rate and the lower the temperature, which is because the PCM above the fins can absorb more heat from the upper surface of the fin through natural convection. Maintaining a constant total volume of fins, the effect of multiple annular fins is studied. The results show that multiple annular fins have larger heat transfer areas and more uniform fin distribution, resulting in lower temperature and temperature difference of the heat source surface. Furthermore, the use of multiple fins of unequal height, with bottom fins being higher, is found to be more effective. The best improvement in the thermal management performance of the system is achieved when the height of the fins is 4, 8, and 11 mm from top to bottom, respectively.