Experimental study on the 3D-flow field of a free-surface vortex using stereo PIV

Experimental study on the 3D-flow field of a free-surface vortex using stereo PIV

Duinmeijer, S.P.A. (TU Delft Sanitary Engineering)
Oldenziel, G. (TU Delft Fluid Mechanics; Deltares)
Clemens, F.H.L.R. (TU Delft Sanitary Engineering; Deltares)

2020

In order to analyse the flow characteristics of free-surface vortexes and to validate the Burgers vortex model by using stereo particle image velocimetry, experiments are conducted in a 600 mm diameter vortex tank. Measured axial velocities indicate that 10–25% of the flow is transported through the vortex core. The velocity profiles show that the axial flow is concentrated in a domain bounded by two times the core radius. Despite Burgers’ assumption of radially independent axial velocity profiles, the model quantifies the tangential velocity profile within a relative uncertainty of circa 10%. The measurements show that it seems valid to use Burgers’ model to obtain an estimate for the core radius by taking the average axial velocity over a radial domain of approximately 2.2 times the core radius. The Burgers model quantifies the air core depth with an uncertainty of 20% relative to the measurements. When compared with the magnitude of vorticity diffusion by molecular viscosity, the experiments show that there is no significant diffusion by radial turbulence.

Air core depth
axial vortex flow
Burgers vortex model
experiments
stereo particle image velocimetry (SPIV)
vortex core radius
vortex dynamics

http://resolver.tudelft.nl/uuid:32d5e6ab-a615-4322-8952-135b47175302

https://doi.org/10.1080/00221686.2018.1555558

0022-1686

Journal of Hydraulic Research, 58 (1), 105-119

Institutional Repository

journal article

© 2020 S.P.A. Duinmeijer, G. Oldenziel, F.H.L.R. Clemens