F. M. Vargas

A Total Concentration Method for Modeling of Deposition

This article presents a fixed-mesh total concentration method for modeling of deposition processes. It is adapted from the total concentration method initially proposed for etching process. The total concentration is defined as the sum of the concentration of the to-be-deposited (particles) and deposited materials (deposit). With this definition, the conservation equation for the total concentration, containing the interfacial conditions, can be derived and solved on a fixed mesh. The moving depositing front is captured implicitly by the concentration of the deposited material. The proposed method is validated against known exact solutions for a few one-dimensional deposition problems and solution from the level-set method for a two-dimensional problem. The method is used to investigate two-dimensional deposition without and with fluid flow coupled.

Experimental Investigation of a Two-Phase Drainage Process in Porous Media

This paper presents an experimental study of two phase water-oil displacement in transparent porous media model made of mini-channels. The working fluid (water or/and oil) was injected into the porous matrix using a syringe pump with a constant flow rate. The influence of gravity and flow rates were studied. The volume fraction was defined and measured during the drainage. Two different experimental configurations, namely vertical and horizontal mini-channel were studied. For the vertical mini-channel, two injections, namely gravity-assisted (top-to-bottom) injection and anti-gravity (bottom-to-top) injection were performed. Experiments using horizontal mini-channel were also performed with the inlet and outlet placed on the same horizontal plane. It was observed that the gravity has significant effect in case of gravity-assisted injection and did not influence the anti-gravity injection or the horizontal injection setups.Copyright

Pore-Scale Investigation of Two-Phase Drainage Process in a Microchannel

This article presents a level-set method to investigate two-phase drainage of oil by water in microchannel with numerous blockages in the middle section, mimicking a porous medium of different permeability at the pore-scale level. The presented framework is intended for gaining an understanding of the nature of flow and transport at the pore-scale level. In particular, the sweeping efficiency for the drainage process is parametrically studied for system with different viscosities and surface tension.Copyright

A Level-Set Method for Particle Deposition on Surfaces

This article presents a fixed-mesh approach to model convective-diffusive particle deposition onto surfaces. The deposition occurring at the depositing front is modeled as a first order reaction. The evolving depositing front is captured implicitly using the level-set method. Within the level-set formulation, the particle consumed during the deposition process is accounted for via a volumetric sink term in the species conservation equation for the particles. Fluid flow is modeled using the incompressible Navier-Stokes equations. The presented approach is implemented within the framework of a finite volume method. Validations are made against solutions of the total concentration approach for one- and two-dimensional depositions with and without convective effect. The presented approach is then employed to investigate deposition on single- and multi-tube arrays in a cross-flow configuration.Copyright