Simulation methods for complex fluids and soft materials
The purpose of this study is to numerically investigate the behavior of active systems. These are systems composed by particles that are intrinsically in non-equilibrium since they are self-propelled (i.e. they have an internal motor of propulsion). At high densities such particles exhibit a wide range of collective phenomena, such as cluster formation or spontaneous organization in confined geometries.
These systems had been previously studied using microscopic models. We use instead a continuous approach: the Phase Field Crystal (PFC) method, a method that comes from dynamical density functional theory (DDFT) and that bridges the gap between microscopic theories and a phase field approach. The equations resulting from this method are partial differential equations (PDE) that can therefore be coupled to other PDEs. This allows us to include hydrodynamic interactions via a coupling with the Navier-Stokes equation. As a consequence, we are able to describe the motion of active particles, called swimmers in this case, in a fluid. We use adaptive finite elements to solve the resulting system of PDEs.
This work should further investigate the PFC method and some of its extensions, such as the vacancy PFC, but it should also allow us to numerically reproduce some experimental results about swimmers and their dynamics.
Project duration: 10/2015 - 09/2018
Funded by: ESF young researchers group "Computer Simulations for Materials Design" (CoSiMa) proposed by the Dresden Center for Computational Materials Science (DCMS), which is supported by the support-the-best program within the institutional concept of TU Dresden