A FINITE ELEMENT BASED PARTITIONED COUPLING METHOD FOR THE SIMULATION OF FLOW-INDUCED FIBER MOTION

A finite element based partitioned coupling method is presented for the simulation of flow-induced fiber motion in this paper. Quasi-static Stokes equation is used as the governing equation of the fluid domain. Mixed finite element is used to solve it. Fiber motion is modeled as a nonlinear geometric dynamic problem. Total-Lagrangian incremental finite element method is used to address the nonlinear geometry. Bathe method is applied to discretize the time domain. Then, two domains are coupled by a loosely partitioned coupling strategy. The derived method can be applied to the simulations of fiber motion in the low Reynolds number fluid, e.g. an injection molding process for manufacturing short fiber reinforced composite materials. In this paper, the effects of fiber shape, axis ratio of fiber, and boundary effect on the fiber's motion are discussed. A phenomenon of repulsion is found in a simulation of the double-particle motion immersed in the double Couette flow.