Numerical simulations of binary fluids confined between moving, rough surfaces

COLL 357

Rolf Verberg, Anna C Balazs, and Olga Kuksenok. Chemical Engineering Department, University of Pittsburgh, 1249 Benedum Hall, Pittsburgh, PA 15261
We present simulation results of binary fluids between moving, rough surfaces. Our aim is to develop mesoscale models for tribochemistry. Through these simulations, we investigate the in situ behavior of these systems, including formation of surface-active molecules, the diffusion of these molecules to the surfaces and interaction between the surfaces. We used the lattice Boltzmann method to simulate the behavior of a confined binary fluid. The confining surfaces exhibited a certain degree of roughness. We first studied phase separation under shear, both for regular surfaces like a saw-tooth pattern, as well as for irregular surfaces where the location and size of asperities was randomly generated. As far as we know this is the first systematic lattice Boltzmann study of binary flows with irregular, moving boundaries. We then consider reactive flow between moving, rough boundaries. The findings from this study provide insight into tribological behavior at complex interfaces.