Aerodynamics of long aspect ratio fibrous particles under settling

Abstract

In present study, the aerodynamic behaviour of long aspect ratio fibrous particles has been investigated experimentally whilst settling in air under super dilute conditions without any influence of secondary flows and at particle Reynolds numbers of 30–80 based on fibre length. A method for laser-based measurement of the orientations and velocities of fibrous particles is presented. The experimental apparatus employs Particle Tracking Velocimetry (PTV) to calculate orientation and velocity based on the two end-points. Fibres' mean vertical and horizontal components of settling velocities, angular velocity, orientation, number density and drag coefficient were calculated to analyze their aerodynamics.