Simulation of shape dynamics of a long flexible fiber in a turbulent flow in the hydroentanglement process

This paper presents the numerical investigation of dynamics of the shape of a long flexible fiber subjected to a turbulent flow field caused by impinging jets in the hydroentanglement process. The shape change of a long flexible fiber is simulated utilizing the rod–chain model following the method developed in Wang et al. [G. Wang, W. Yu, C. Zhou, Optimization of the rod chain model to simulate the motion of a long flexible fiber in simple shear flows, European Journal of Mechanics B/Fluids 25 (2006) 337–347.]. The method is extended to simulate the fiber movement in a turbulent flow field; two-dimensional simulations are performed. The shape of the fiber is determined by forces and torques exerted on it by the surrounding fluid as well as by the neighboring fibers. Numerical results are obtained for two model representations of the same fiber which differ by the number of rods used to represent the fiber.