An improved enthalpy-based lattice Boltzmann model for heat and mass transfer of the freezing process

In the original enthalpy-based lattice Boltzmann model, the heat conduction equation is incorporated with enthalpy formation. The latent heat of phase change is separated from the sensible heat. It is suitable for simulating the non-isothermal phase change problem without fluid flow. In order to investigate the freezing problem involving the fluid flow, an improved enthalpy-based lattice Boltzmann model has been proposed by introducing the solid volume fraction in the particle distribution function evolution equation and considering the forced convection heat transfer of the fluid flow. The model is validated by numerically simulating the solidification in a half-space, solidification from a corner in a quarter-space and the freezing process of a freefalling droplet in a cold space, respectively. Then, in the third case, the advantage of the improved enthalpy-based lattice Boltzmann model has been demonstrated by comparing the simulations based on the improved model and the original enthalpy-based lattice Boltzmann model. These comparisons show that the proposed model is feasible and reliable to simulate the freezing process involving the fluid flow, What's more, the temperature distribution and the solid volume fraction distribution of a freefalling droplet in the freezing process have been discussed. (C) 2016 Published by Elsevier Ltd.