Optimization of the rod chain model to simulate the motions of a long flexible fiber in simple shear flows

A rod-chain model was used to study the dynamics of a long flexible fiber which is suspended in a Newtonian fluid. It was shown that the fiber exhibited different apparent flexibility, which depended on the stiffness of the fiber, the strength of the flow field and the initial configuration of the fiber. Different combinations of rod length and rod number were used to simulate the motions of a long fiber in simple shear flow. Long rods would greatly save the computational resources with the loss of accuracy, while short rods would generate accurate results with the loss of efficiency. An optimum rod length was suggested to balance the requirement of accuracy and efficiency, and it was the function of the relative strength of flow field and the initial angle between fiber and vortex axis.