Comparative study of natural convection melting inside a cubic cavity using an improved two-relaxation-time lattice Boltzmann model

Abstract

In this paper, the effects of heating direction on the natural convection melting in a cubic cavity are comparatively studied by an improved two-relaxation-time (TRT) lattice Boltzmann model, which can not only recover the correct macroscopic equations but also dramatically reduce the numerical diffusion across the phase interface. In order to reveal the effects of heating direction on the melting efficiency at different Rayleigh number (Ra) and Prandtl number (Pr) more clearly, both one-side heating and two-side heating are considered. The present numerical results show that in either case, the melting efficiency is increased with the increase of Ra, and the differences of them mainly depend on the value of Pr and the heating direction. Further, the distributions of streamlines and temperature at various times for different cases are also studied.