Effect of inclination on free convective heat transfer during melting of a phase change material in a rectangular enclosure

Determination of heat transfer during melting in enclosures is important in the design of heat exchangers using phase change material (PCM) for thermal energy storage. Melting of the PCM generally invokes free convection currents in the melt phase depending on the orientation and geometry of the heat transfer surfaces. This paper deals with a computational investigation of the flow patterns and heat transfer rates which develop during the melting of a PCM contained in a rectangular chamber. Effects of heating both the vertical and horizontal faces as well as orientation of the cavity to the gravitational vector are examined. The shapes of the solid-liquid interface demonstrate clearly the generation of the cellular structure in the melt phase when the bottom horizontal face is heated. The cellular structure results in an undulating pattern for the heat transfer distribution on the bottom surface. The number of peaks and valleys in the Nusselt number distribution depends on the thickness of the melt layer.