Linear and angular dynamics of an inertial particle in turbulence

Abstract

Lots of attention has been recently given to the dynamics of inertial particles in turbulence [1, 2, 3]. This knowledge is relevant for many practical situations where objects are being advected by an underlying turbulent flow. One central question concerns the modelling of the forces which act on inertial particles. For objects smaller than the Kolmogorov dissipation length, a pointwise model (PP) including added mass and Stokes drag term has proven quite successful. For larger particle there are noticeable discrepancies compared to experimental observations [4, 5]. This has motivated to include corrections, in particular the inclusion of size effects. Taking into account the non-uniformity of the flow at the particle scale has improved the models [6], but some effects remain, like those associated with the eventual rotation of the particle. We report here an experimental investigation of the 6-dimensional motion (3 space and 3 angle coordinates) of an inertial size particle in a fully turbulent flow.