Particle dynamics in boundary layers below a swirl flow

Samenvatting

The problem of sediment transport is complex, but of great economical, societal and environmental importance. It is suspected that geophysical vortex structures in the sea can transport large amounts of sediment, but a fundamental understanding of this is lacking. In this work, the motion of two different types of particles induced by the flow inside the Ekman and Bödewadt boundary layer in a rotating tank filled with fluid is investigated. The trajectories of the particles are found to be approximated by logarithmic spirals directed towards the center of the tank. It is shown that the velocity profiles normalised by their extreme values collapse to one curve. Furthermore, the relation between the extreme values of the radial and azimuthal velocity, and initial particle radius appears to be linear. These results indicate that the general shape of the trajectories and the timescales of motion are independent of the initial position of the particle on the bottom of the tank.

Datum prijs	31 okt. 2014
Originele taal	Engels
Begeleider	G.J.F. van Heijst (Afstudeerdocent 1) & Matias Duran Matute (Afstudeerdocent 2)