Abstract
In this paper, an improved thermal lattice Boltzmann (LB) model is proposed for simulating liquid-vapor phase change, which is aimed at improving an existing thermal LB model for liquid-vapor phase change [S. Gong and P. Cheng, Int. J. Heat Mass Transfer 55, 4923 (2012)10.1016/j.ijheatmasstransfer.2012.04.037]. First, we emphasize that the replacement of ∇·(λ∇T)/∇·(λ∇T)ρc_{V}ρc_{V} with ∇·(χ∇T) is an inappropriate treatment for diffuse interface modeling of liquid-vapor phase change. Furthermore, the error terms ∂_{t_{0}}(Tv)+∇·(Tvv), which exist in the macroscopic temperature equation recovered from the previous model, are eliminated in the present model through a way that is consistent with the philosophy of the LB method. Moreover, the discrete effect of the source term is also eliminated in the present model. Numerical simulations are performed for droplet evaporation and bubble nucleation to validate the capability of the model for simulating liquid-vapor phase change. It is shown that the numerical results of the improved model agree well with those of a finite-difference scheme. Meanwhile, it is found that the replacement of ∇·(λ∇T)/∇·(λ∇T)ρc_{V}ρc_{V} with ∇·(χ∇T) leads to significant numerical errors and the error terms in the recovered macroscopic temperature equation also result in considerable errors.
Highlights
The lattice Boltzmann (LB) method, which originates from the lattice gas automata method [1], has been developed into an efficient numerical approach for a wide range of phenomena and processes in the past three decades [2,3,4,5,6,7,8,9]
We have presented an improved thermal LB model for simulating liquid-vapor phase change
The Chapman-Enskog analysis has been performed for the GongCheng thermal LB model, which shows that the term ∇ · (λ∇T )/ρcV in the target temperature equation was replaced by ∇ · (χ ∇T ) in the model and some unwanted terms exist in the recovered macroscopic temperature equation
Summary
The lattice Boltzmann (LB) method, which originates from the lattice gas automata method [1], has been developed into an efficient numerical approach for a wide range of phenomena and processes in the past three decades [2,3,4,5,6,7,8,9]. The first category is based on the phase-field multiphase LB method, such as the models developed by Dong et al [17], Safari et al [18,19], and Sun et al [20] In these models, the liquid-vapor interface is captured by solving an interface-capturing equation (e.g., the Cahn-Hilliard equation) and a source term is incorporated into the continuity equation or the interface-capturing equation to mimic the phase change. [29], Li et al devised a hybrid thermal LB model for liquid-vapor phase change, which employs a finite-difference scheme to solve the temperature equation. Owing to the fact that many researchers prefer to use a thermal LB equation rather than a traditional numerical scheme, the thermal LB equation–based models are widely utilized in the literature for simulating liquid-vapor phase change.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
