Application of lattice Boltzmann method and spinodal decomposition phenomenon for simulating two-phase thermal flows

In present study, by using thermal model of passive scalar and Shan-Chen model two-phase lattice Boltzmann, the two-phase thermal flows were investigated. The dynamics of such flows involves several complexities due to the complex interaction of several physical phenomena such as surface tension, phase transition etc., which should be accounted for in a simulation. A quick review of the literature shows that the lattice Boltzmann method (LBM) was successfully employed to simulate a variety of complex fluid flows such as multiphase flows in porous media. In this paper at first, the thermal model of passive scalar and then, Shan-Chen model in the isothermal state are presented. Then, by using Spinodal decomposition phenomenon in the isothermal and thermal states they were compared with each other. Also, the droplet on the heated wall was studied for different diameters and the location of drop on the heated wall in high Rayleigh numbers (105) and Reynolds numbers (20 to 500) and also, different diameters of drop were investigated. In Spinodal decomposition of phases, the enhancement of drop convergence time and more resistance of smaller drops were observed in thermal model. In general, the results indicate that the existence of temperature in multi-phase problem postpones achieving the steady state and the spurious flows created in the interface region affect the temperature field.