8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Tue 611:23-14:00P9.39Dynamic approach to flowing liquids in confined systemsSimone Melchionna 11 CNR-ITALY, Piazzale Aldo Moro 2, 00185, Rome, ItalyWe present the detailed analysis of the transport of spatially inhomogeneous fluids and the interplaybetween structural and dynamical properties varying on the atomic scale. The present treatmentis based on different areas of liquid state theory, namely kinetic and density functional theory(DDFT) and their implementation as an effective numerical method via the Lattice Boltzmannapproach. By combining the first two methods we are able to describe on equal footing theirstructural and hydrodynamic properties beyond the usual Smoluchowski overdamped description.The method focuses on the evolution of the singlet phase space distribution function involving anEnskog interaction kernel, further simplified by separating the long lived hydrodynamic modesfrom the fast kinetic modes and by invoking a coarse graining ansatz. The DDFT dynamics isrecovered under the application of a stochastic thermostat, physically representing an inert solvent.For particles evolving under Newtonian dynamics, the system diplays propagating modes and thedamping occurs only when gradients of the velocity and temperature fields are present. At firstwe show that the resulting system has the correct equilibrium behavior and non-trivial transportproperties. Next, we discuss how the transport equation is a self-consistent dynamical equationamenable to numerical simulations in the framework of the Lattice Boltzmann method. The useof the LB method is particularly appealing regarding the applications to confined fluids, wherestandard hydrodynamics becomes questionable. In addition, the method is flexible and offers apowerful alternative to Molecular Dynamics simulations.39