Absorption of Microdrops: Effect of Multi-Layer Porous Media Structure Parameters

This paper presents the numerical investigation of the absorption of two microdrops deposited sequentially on the surface of single- and double-layer porous media at a different location of the centers of droplets deposition. A numerical solution of the Euler equations taking into account surface tension forces and the unsteady filtration equation was used to model the fluid flow from a droplet into a porous media. The layers of porous media were characterized by effective permeability coefficients dependent on porosity and pore size. The change of the droplet shape during absorption, the coordinates of absorption front propagation in a porous media and the field of velocities and pressure are the output data of a problem. The effect of the structural parameters of the multilayer porous media and the relative location of deposited droplets on the rate of absorption and distribution of absorbed fluid is analyzed using the numerical experiment. It is shown that the presence of the second layer can have a significant effect on the duration and result of droplet absorption. The relative size of pore in layers is found to be the main parameter that governs the effect of the second layer.