Applications are invited for a Research Technician position in “Friction and contact forces from the Theory of Coarse-Graining” at the CFD group (BCAM) in collaboration with the UNED. Suspensions of particles are ubiquitous in nature and in technological applications. They are a paradigmatic example of complex fluid displaying non-trivial rheological and microstructural behaviour. Even the simplest case of spherical rigid non-Brownian suspensions exhibit fascinating non-Newtonian behaviour. While much is known about the rheology of hydrodynamics-dominated dilute suspension, the community is now addressing the challenge of considering concentrated suspensions, where hydrodynamics is restricted to lubrication effects and other surface-surface interactions begin to dominate. In the present project, we aim at using the Theory of Coarse-Graining (ToCG) in order to motivate a specific model for the surface-surface interaction between suspended particles. The ToCG, also known as the Mori-Zwanzig approach, GENERIC, or simply Non-Equilibrium Statistical Mechanics, is a general framework to derive the equations governing the evolution of Coarse-Grained variables describing the system at a coarse level of description, starting from the underlying Hamiltonian dynamics of the atoms or molecules. It provides, therefore, the link between Molecular Dynamic (MD) simulations and the corresponding quantities in a coarse-grained theory. The RT candidate will work under the supervision of Ikerbasque Prof. Marco Ellero (CFD group, BCAM) in collaboration with Prof. Pep Español (UNED), on the developments and use of microscopic particle-simulation methods to better understand the origin and improved modelling of frictional processes in granular media. |