The Sedimentation of Slim Flexible Particles in Stokes Flow

Abstract

Background/Objectives: The dynamics of elastic slim particles (filaments) surrounded by fluid flow is a noteworthy topic of study because of its application in natural sciences and industrial processes. When deformation of elastic particle is large many complications arise which needs specific consideration in order to develop an efficient method for modeling the solid-fluid interaction accurately and with acceptable computational cost. Method: In order to study the sedimentation process of filament which is immersed in a quiescent fluid flow, we constitute related governing equations based on nonlocal solid-fluid interaction coupling with slender body theory. The fluid flow governed by Stokes assumptions which allow us to use superposition principle. Also, the extracted equations rearrange by two controller parameters Elasto-gravitation, β, and Slenderness-parameter, ϵ. Findings: A Highly Flexible filament (HF-filament) and a Moderately Flexible filament (MF-filament) have examined by mentioned method. The results show that the HF-filament fall on a periodic motion during the sedimentation process. This periodic motion leads to a set of unbalance forces along the filament which causes a permanent lateral drift. In the other side the MF-filament meets an equilibrium point with a final constant U-shape. Also, in order to validation we compare the outcome data with the results obtained by local and multiple scale analysis methods. Application/Improvements: The approach have been presented by this paper can be used in different fields which there are any necessity to simulating slim particles motion more simple and with less computational cost in compare with conventional methods.