Class demo experiment
- Introduction
- Spinup with rough end walls (coming soon)
- Taylor-Proudman theorem (coming soon)
- convection with and without rotation (coming soon)
- Detailed description of the device (coming soon)
Introduction
As part of the educational program at ETH our laboratory is involved in various classes including an introductory class of Geophysical fluid dynamics. To illustrate some fundamental properties of rapidly rotating fluid we developed a versatile portable rotating straight cylinder setup. This apparatus is also available to MSc students to carry out projects related to rotating fluid dynamics, e.g. Spinup with rough end walls.
The demo class setup make use of the state of the art diagnostic equipment available in the laboratory such as Laser Doppler Anemometer (LDA), Accoustic Doppler Velocimeter, 100fps CCD.
Spinup with rough end walls (Yoann Charles)
Angular momentum exchange between the liquid core or subsurface ocean and the solid mantle or ice shell is fundamental ingredient to establish the evolution of the orbits of a celestial object.
During his Master I project, Yoann Charles investigated the effect of an end wall roughness on the viscous coupling in a spinup experiment using the demo class apparatus with sand paper glued at the bottom. The viscous coupling can be probed by monitoring the resynchronization time of the rotating fluid after suddenly accelerating the tank. Using Laser Doppler Measurement, we observe that the resynchronization time decreases with the roughness as long as it is smaller than the typical thickness of the regular viscous boundary layer:
