Mesoscopic lattice Boltzmann modeling of soft-glassy systems: Theory and simulations

A multicomponent lattice Boltzmann model recently introduced [R. Benzi et al., Phys. Rev. Lett. 102, 026002 (2009)] to describe some dynamical behaviors of soft-flowing materials is theoretically analyzed. Equilibrium and transport properties are derived within the framework of a continuum free-energy formulation and checked against numerical simulations. Due to the competition between short-range interspecies repulsion and midrange intraspecies attraction, the model is shown to give rise to a very rich configurational dynamics of the density field, exhibiting numerous features of soft-flowing materials such as long-time relaxation due to caging effects, enhanced viscosity and structural arrest, aging under moderate shear, and shear-thinning flow above a critical shear threshold. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3216105