Study on the melting process of oxide layer of micrometer-sized aluminum particles using Lattice Boltzmann method

Abstract

The study of the oxide layer in aluminum-oxygen combustion is crucial for the subsequent reaction. In this article, a 2-D lattice Boltzmann model is established and the effects of different Rayleigh number, oxide thickness, Ste number, and porosity on melting speed and melting time are studied based on the enthalpy method. The results demonstrate that a low Rayleigh number has no noticeable impact on the melting process. However, a rise in the Rayleigh number can obviously advance the melting process when the Rayleigh number exceeds 105. The melting speed slows down and the melting time prolongs as the oxide thickness increases, but the effect of thickness on melting speed decreases progressively with increasing thickness. In contrast, rising Stefan number can promote the melting process, and the effect is more pronounced at lower Stefan number. High porosity is beneficial to the development of natural convection and is able to significantly boost the melting process.