Motion of a self-propelled rod with Brownian and hydrodynamics interactions

Abstract

The dynamic behaviour of a self-propelled rod in a three-dimensional system with cut-and-shifted Lennard-Jones interaction is studied by stochastic Eulerian Lagrangian method which coupled the coarse-grained microstructure degrees of freedom to continuum stochastic field, and the relaxation and thermal fluctuation of the fluid dynamics mode are taken into account. The diffusion of the self-propelled rod is found to have four regimes. The distributions of the horizontal displacements tend to bimodal non-Gaussian at long time when the self-propelled forces are introduced. Furthermore, we study the distributions of the rod velocities in parallel and perpendicular to the rod axis in the body frame. They are all Gaussian, and their standard deviations increase when the self-propelled forces increase.