Related Experiment Video
Updated: Aug 29, 2026

Multiscale Sampling of a Heterogeneous Water/Metal Catalyst Interface using Density Functional Theory and Force-Field Molecular Dynamics
Published on: April 12, 2019
Lattice-Boltzmann model based on field mediators for immiscible fluids
L O E Santos1, P C Facin, P C Philippi
1Mechanical Engineering Department, Federal University of Santa Catarina, 88040-900 Florianópolis, Santa Catarina, Brazil. emerich@lmpt.ufsc.br
Abstract:
In this paper, a lattice BGK (Bhatnagar-Gross-Krook) model is proposed for immiscible fluids. Collision operator is decoupled considering mutual and cross collisions between lattice particles, with three independent parameters related to the species diffusivity and to the viscosity of each fluid. Field mediator's concept, described by Santos and Philippi [Phys. Rev. E 65, 046305 (2002)], is extended to the framework of the lattice-Boltzmann equation and interference between mediators and particles is modeled by considering that there is a deviation in particles velocity, proportional to the mediators' distribution at the site. A Chapman-Enskog analysis is performed leading to theoretical predictions of the macroscopic equations inside the transition layer and to the transition-layer thickness. Chapman-Enskog analysis is restricted to near-equilibrium states and was unable to predict the correct second-order interfacial tension dependence on the modeled long-range fields intensity. Interfacial tension was, only, correctly retrieved using a nonequilibrium solution. Theoretical predictions are compared with simulation results and the model is tested considering its ability in describing the dynamical behavior of the interface and Galilean invariance.
Related Concept Videos
Fluid Mosaic Model
Fluid Mosaic Model
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
The Kinetic Model of Gases
Distribution of Molecular Speeds

