## Seminarium Zakładu Mechaniki i Fizyki Płynów## "A multiple time-stepping scheme for dynamic simulations of dilute sedimenting suspensions"## mgr Gustavo Abade, Instytut Fizyki Teoretycznej UW |

The purpose of this seminar is to present computer simulations of dilute suspensions undergoing gravity induced sedimentation. It is considered a system of non-Brownian spheres, which may differ in radius and density, sedimenting in a Newtonian fluid at low Reynolds number. Attention is focused on the description of a multiple time-stepping scheme to calculate the time evolution of particle configuration. This scheme is employed in an attempt to reduce the time spent on calculating hydrodynamic interactions, which is $O(N^2)$ in a system of N particles. Results for the hydrodynamic self-diffusion coefficients will be presented for mono and polydispersions.