Phenomenological Study of Droplet Behavior Passing through a Porous Medium at Pore-Scale, Using Lattice Boltzmann Method

Single-phase and multiphase flows in porous media, both in nature and in industries, are very important for the wide range of researchers. Specifically, they have many applications in processes such as plant leaf sprays, pesticides, printers, and penetration of rain or surface waters to the soil. The main objective of this research is the analysis of droplet interaction with a porous medium. The droplets are of have similar scale of the pores of the porous medium, which its application is penetration of droplet with specific size into the bed rocks and filtering the droplets. In this study, the porous medium consists of square obstacles with porosity value of 0.8, is exposed to a two-phase flow. The porous medium that is wetted by primary phase is intruded by a droplet. The regimes of the flow is non-Darcian. The effective dimensionless numbers of the physics are Reynolds, Capillary, and Ohnesorge number. The values of exerted dimensionless pressure in the study are 0.000108, 0.000144, and 0.000180 and the range of Ohnesorge is 0.19-0.76. The factors connected with the droplet and secondary phase (related to fluid’s properties), such as surface tension and density ratio along with flow characteristics (such as exerted pressure) are effective and create variations in the behavior of droplet breakup, which in the frame of a comprehensive parametric study, are investigated. The types of droplet breakup, categorized and are presented by characteristic pictures of each case. Moreover, the zoning of each case in Re-Ohn Figure (as a droplet phenomenological breakup map on the basis of two dimensionless number and exerted pressure) is done. The results of the simulations, show the ability to predict droplet behavior in the porous medium using presented charts and moreover, make a comparison on relative effect of effective factors, are the redeeming features of this study. In this study, Lattice Boltzmann method is used as the numerical method that shows a high degree of capabilities and flexibility in relation with multi-phase flows and porous media.