ON THE FORMATION OF PARTICLE SHEATHS IN COLUMNAR VORTICES.

Abstract

An approach to study the formation of cylindrical dust sheaths concentric with the axis of symmetry in columnar vortices is presented wherein the drag forces arising from radial motion of the fluid are assumed negligible. It is shown for four representative profiles of the tangential velocity component of the fluid that a particle sheath will form. The time required for its formation, the location of the sheath, and its evolution in time are in agreement with the available field evidence. Also, a two-celled vortex flow field is shown to produce a two-sheath structure. Refs.