3D ANALYSIS OF FLOW AROUND A VERTICAL CYLINDER ON A SCOURED BED

Tomonao Kobayashi

Abstract


Velocity distributions around a vertical cylinder on a scoured seabed under waves have been evaluated in three dimensions using a laser Doppler anemometer and the mass-consisstent model to explain the mechanism of local scouring in the wave fields. Through their comparisons with the measurements over a flat bottom under the same conditions, effects of the scoured seabed configuration on the vortex behavior around a cylinder and the near-bed flow structures have been clarified. Namely, the scoured seabed topography causes deformation of the vortices and the flow field from a quasi-two-dimensional structure observed above the flat bed into a complex three-dimensional structure. The flow around a cylinder has also been simulated numerically with a three-dimensional vortex segment model. The results have shown a good agreement with those in the experiments.

Keywords


scour; scoured bed; flow analysis; vertical cylinder

Full Text: PDF

Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.