Large eddy simulation of inertial fiber deposition mechanisms in a vertical downward turbulent channel flow

Abstract

The deposition pattern of elongated inertial fibres in a vertical downward turbulent channel flow is predicted using large eddy simulation and Lagrangian particle tracking. Three dominant fibres deposition mechanisms are observed, namely, diffusional deposition for small inertial fibres, free-flight deposition for large inertial fibres, and the interception mechanism for very elongated fibres. The fibres are found to exhibit orientation anisotropy at impact, which is strongly dependent on the fibre elongation. An increase in the fibre elongation increases the wall capture efficiency by the interception mechanism. The diffusional deposition mechanism is shown to dominate for fibres with large residence time,