Motion of Flexible Fibers in a Newtonian Flow

Abstract

The objective of this study is to well understand the interaction between the configuration of flexible fibers and flow kinematics in fiber suspension flows. In this framework, the evolution of the configuration of a single fiber in a simple shear flow at low Reynolds number was numerically analyzed on the basis of an 'immersed boundary method' developed by Peskin. In the computations fibers with force-free configuration of being straight were used. While deformation of a fiber is fundamentally three-dimensional, stretching/compression and bending deformations in the plane of flow were simply assumed.In Part 2 of the series of papers, the effects of fluid viscosity and shear rate on the evolution of the configuration of a single fiber and flow kinematics were described. The behavior of a fiber becomes more complex as the fluid viscosity increases. Furthermore, it was confirmed that a flow-induced bending parameter, which is a function of fiber length, bending stiffness, fluid viscosity and shear rate, is a useful dimensionless parameter for classification of rotation of an elastic fiber, such as rigid rotation, springy rotation, S-turn, snake turn and complex rotation.