Lattice Boltzmann simulation of melting in a cubical cavity with a local heat-flux source

A three-dimensional numerical study is conducted to investigate the effect of heat-flux source location on the melting of phase change material (PCM) in a cubical cavity. An enthalpy-based incompressible thermal lattice Boltzmann model (iTLBM) has been established and validated by two benchmark problems. In order to reveal the effect of heat-flux source location in melting rate in three-dimensional space, both horizontal and vertical locations are considered. The numerical results show that the size of local heater and its heat flux play an essential role in melting rate. Furthermore, the variation of the location of the heat-flux source from both sides to the middle region of the cavity leads to the increase of the total heat flux on the interface, which also results in the increase of melting rate. Finally, we also find that the melting rate increases as the location of the heat-flux source is changed from top to the bottom region of the cavity, which is attributed to the enhancement of convection heat transfer.