Impact of shape of container on natural convection and melting inside enclosures used for passive cooling of electronic devices

摘要

The present paper numerically analyzes a passive cooling system usingenclosures with different geometries filled with thermal conductivity-enhancedphase change material (PCM). A numerical code is developed using anunstructured finite-volume method and an enthalpy-porosity technique to solvefor natural convection coupled to a solid-liquid phase change. Five geometriescontaining the same volume of PCM are compared while cooling the same surface.The unsteady evolution of the melting front and the velocity and temperaturefields is detailed. Other indicators of cooling efficiency are monitored,including the maximum temperature reached at the cooled surface. Thecomputational results show the high impact of varying geometry: a maximumtemperature difference as high as 40^{\circ}C is observed between two of theenclosures. The best efficiency is obtained for an enclosure shifted verticallyrelative to the cooled surface. Other findings and recommendations are made forthe design of PCM-filled enclosures.