Abstract
Fiber orientation of dilute and concentrated suspensions in elongational flow was simulated by using a particle simulation method (PSM). In this method, a fiber is modeled with an array of spheres and the motion of hydrodynamically interacting fibers is followed by solving the translational and rotational equations of motion for each constituent sphere. Computer simulation was performed to predict the microstructure and the rheological properties of rigid fiber suspensions of aspect ratios 5 and 10 at various concentrations (0.1∼22.5 vol%). The computer simulations demonstrate that fibers scarcely interact with each other even in the concentrated regime and their motion follows the classical theory, which is based on the dilute regime.