Random walk implementation of rotary diffusion in Lagrangian models of fiber orientation

Abstract

A comprehensive comparison of the Lagrangian and Eulerian frameworks for one-way coupled simulations of fiber suspension flows is performed for 2D and 3D models of orientation dynamics. An alternative approach to modeling the interactions of fibers is proposed for the Lagrangian framework. The presented methodology is based on the idea of the random walk, which is commonly used for modeling diffusion-like processes due to the Brownian motion of molecules. It is shown that a restriction of the random walk to the unit sphere provides an accurate description of orientation changes caused by interactions between fibers.