Mathematical Simulation of Flexible Fiber Dispersion in a Homogenous Turbulent Flow

Abstract

Dispersion of inextensible flexible fibers in a simulated isotropic pseudo- turbulent flow field is studied. Turbulence fluctuation velocities are simulated by the Kraichnan Gaussian random field model. Fibers are assumed to be inextensible but completely flexible. That is, fibers have no stiffness and offer no resistance to bending. In the simulation, a flexible fiber is divided into many segments. Interactions of each element with the adjacent elements are through axial forces that are evaluated as part of the solution. For different fiber diameters, aspect ratios, and initial configurations, deposition velocities are evaluated, and the fiber dispersion is analyzed. An empirical equation for the deposition velocity of flexible fibers is also developed. The results for flexible fiber deposition rate are compared with those for rigid straight fibers and the empirical equation predictions.