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 flow kinematics and configuration of multiple flexible fibers in a simple shear flow at low Reynolds number was numerically analyzed using an 'immersed boundary method' developed by Peskin. In the computations fibers with force-free configuration of being straight were used, and stretching/compression and bending deformations in the plane of flow were simply assumed.
In Part 3 of the series of papers, we described the effects of the parameters such as number of fibers, initial distance between fibers, bending stiffness of fibers and fluid viscosity on the hydrodynamic interaction between fibers and evolution of the flow kinematics. It was confirmed that the behavior of fibers and the flow kinematics become more complex owing to significant hydrodynamic interactions as the number of fibers increases, e.g., a fiber moves toward and beyond a forward fiber or a fiber on the left hand side can only rotate in a strong vortex and almost never translates.