Lattice gas simulations of liquids

Summary of topics:

Lattice gas models serve as simplified, but powerful, tools to generate time evolution dynamics of non-compressible liquids under very flexible boundary conditions.

GUI. This area is very preliminary and is a work in its infancy. The lattice gas model used is the FHP III and there is a GUI (choose LATG from the list) that allows maximum real-time interaction with a running simulation.

Phase Separation. The goal is to model the dynamics of immiscible liquids in a porous media. Some very preliminary results on simple phase separation on a 128x128 and a 512x512 system size have been succesfully done.

Driven System. Of particular interest are the results from an immiscible liquid system under driving force dynamics. Preliminary results of the particle-injection on the left side of the system (under wind tunnel BC) are shown as a function of time.

Capillarity. Capillarity can be achieved by giving "color" to the obstacles and walls in an inmiscible liquid simulation. Take a look at a 512x64 simulation where the degree of blue- to red-philic character of the walls of the tube is changed.

Capillarity Pressure. Capillarity pressure arises directly from the surface tension between two liquids and the interactions of one of the liquids and the walls of the system. The capillarity pressure can draw one liquid to displace another, even in the abscence of external driving forces. In a blue-philic simulation, the blue phase pushes out of the tube the red.

Pinning of Interface Front. When a non-wetting fluid invades a medium already occupied by a wetting fluid in a porous media, there is the possibility of pinning of the interface front, or that under a constant input pressure the non-wetting fluid would not penetrate into the media. A simulation of this drainage situation is presented where the flux of liquid through the porous media is seriously slowed down by the capillary forces.

Force Interface Front In an imbibition simulation (driven liquid wets obstacles) different forms of roughness for the interface morphology are expected. Depending on the obstacle porosity, geometry and pressure that drives the system, a flat-to-rough transition of the interface should appear.

Forced ILG through Porous Media with Variable Wettability In a driven ILG through porous media, the character of the interface between the liquids is dependent on the wettability of the medium. A transition is observed from a rather flat to a fingered morphology.

Force ILG through Porous Media as a function of particle density Driven immiscible liquids as a function of particle density shows an interesting variability in the character of the interfase, namely the interfase seems to get smoother with particle density.