Lattice Boltzmann simulations of melting in a rectangular cavity heated locally from below at high Rayleigh number

TL;DR

This paper introduces a novel lattice Boltzmann model for simulating high Rayleigh number melting in a rectangular cavity, demonstrating improved accuracy and analyzing the impact of heated region placement on melting dynamics.

Contribution

A new block triple-relaxation-time lattice Boltzmann model is proposed for high Rayleigh number melting simulations, reducing numerical diffusion and enabling detailed analysis of heating location effects.

Findings

The B-TriRT model significantly reduces numerical diffusion at the phase interface.

The location of the heated region critically influences melting rate.

Full melting occurs earliest when the heated region is centrally located.

Abstract

This work presented a block triple-relaxation-time (B-TriRT) lattice Boltzmann model for simulating melting in a rectangular cavity heated from below at high Rayleigh (Ra) number (Ra = 108). The test of benchmark problem shows that present B-TriRT can dramatically reduce the numerical diffusion across the phase interface. In addition, the influences of the location of the heated region are investigated. The results indicate that the location of heated region plays an essential role in melting rate and the full melting occur earliest when the heated region is located in the middle region.