A tethered bluff body is a configuration commonly occurring in engineering applications (e.g. blimps, ocean buoys) as well as in nature (e.g. seed or pollen dispersal by plants). Here we study the vortex-induced vibrations of a tethered sphere using tomographic particle image velocimetry that allows us to measure the instantaneous 3D flow field in the wake of the sphere.
The research objectives: (i) Measurement of the 3D wake structure of a tethered sphere over a range of Reynolds numbers and mass parameters. (ii) Determination of the fluid forcing acting on the tethered sphere using the measured 3D flow fields. This will provide insight into the relevant energy transfer mechanisms between fluid and sphere and possible applications to green energy harvesting applications.