چكيده به لاتين
Lattice Boltzmann Method (LBM) is one of the Computational Fluid Dynamics (CFD) methods that has a mesoscopic nature. In pase two decades, this method has been developed to a powerful and efficient simulation method for a wide range of problems like flow in porous media, turbulence and multiphase flows. From the emergence, utilization of LBM in multiphase flows was one of its important applications. So far, numerous two phase models have been presented in categories of color gradient, free energy, pseudopotential and phase field. However, not until recently in comparision with two phase models less attention was paid to the three phase models and only few models have been stablished.
In this work, after investigating some of LBM three phase models, the model of Liang et al. hase been chosen to impelement in a numerical code. Afterwards, advantages and limitations of the model on several cases were studied and then the model was used to simulate two immiscible drops collision in a dense ambient. The problem of drops collision (and bubbles) is of great importance in sprays, evolution of clouds and rain drops, encapsulation and produced water (waste water) teeatment. It is found that increasing density ratio will decrease the probability of drops coalescence in large collision parameters. Also, reduction in viscosity ratio will extend the coalescence regime with traped phase and shifts the coalescence-slip regim border to larger collision parameters.
Keywords: Lattice Boltzmann Method, Phase field, Ternay flow, Drops and Bubbles Collision
