Melting of a PCM inside a vertical cylindrical capsule

Abstract

Abstract A numerical study of natural convection melting of a phase change material within an isothermal vertical cylinder was conducted. The governing conservation equations are formulated in terms of a stream function, vorticity and temperature. Body‐fitted co‐ordinates are employed for tracking the irregular shape of the timewise changing solid–liquid phase front. Results show that the convective flow patterns and time evolution of the phase front, resulting from simultaneous bottom, side and top heating, are far more complicated than those for the melting from a single isothermal boundary. The heat transfer rate at the top surface is found to decrease monotonically to zero as convection is fully developed in the melt. The highest heat transfer rates are observed at the bottom surface where Bénard convective cells develop. Due to the convective motion of the melt along the vertical heated wall, the onset of Bénard convection occurs at a much earlier time than that for the case of melting within a cylinder heated from below.