Stochastic dispersion of ellipsoidal fibers in various turbulent fields

• Dispersion and deposition of ellipsoidal fibers are evaluated in turbulent flows.
• Lagrangian approach is used to simulate the motion of fibers.
• The influence of turbulent fluctuations is incorporated using stochastic modeling.
• Performance of stochastic models for turbulent fluctuations is evaluated.
• Influence of fluctuating velocity gradient on the fiber deposition velocity is small.

In this study dispersion and deposition of fibers of various sizes in fully developed turbulent pipe and duct flows were analyzed for a range of flow Reynolds numbers. Fibers translational and rotational equations of motion were solved using the Lagrangian approach assuming one-way interaction. The influences of turbulent fluctuations were included using appropriate stochastic models for fluctuating velocity and velocity gradient components. Performance of the stochastic model was evaluated for several test cases including dispersion of fibers in a synthesized isotropic homogenous turbulent flow field, inhomogeneous turbulent flow field, and fully developed turbulent pipe and duct flows. The simulation results were compared with earlier numerical and experimental studies for flow statistics and deposition velocity and good agreements were observed. It was shown that using appropriate stochastic models leads to satisfactory evaluation of dispersion and deposition of fibers in turbulent flows.