Dynamics of Flexible Filament in Viscous Oscillating Flow

Abstract

The dynamics of flexible filament in a viscous fluid is a complex fluid–structure interaction problem that has wide scientific and engineering applications in emerging fields such as biomimetics and biotechnology. Coupling the structural equations with fluid flow poses a number of challenges for numerical simulation. In this regard, techniques like immersed boundary method (IBM) have been quite successful. In the present study, a two-dimensional numerical simulation of flexible filament in a rectangular channel with an oscillating fluid flow at low Reynolds number is carried out using IBM. The discretization of governing continuity and Navier–Stokes equation is done by finite volume method on a staggered Cartesian grid. SIMPLE algorithm is used to solve fluid velocity and pressure terms. The filament mechanical properties like stiffness and bending rigidity are incorporated into the governing equation via Eulerian forcing term. An oscillating pressure gradient drives the fluid while the flexible filament is fixed to the bottom channel wall. The simulation results are validated with filament dynamic studies of previous researchers. The interaction of the filament with nearby oscillating fluid motion is well captured by the developed numerical model.