Abstract
The early evolution of an initially columnar vortex normal to a solid wall was examined. The vortex was generated by a pair of flaps in a water tank. Detrimental effects from the wall during the vortex generation were avoided by producing the vortex normal to a free surface and subsequently bringing a horizontal plate into contact with the surface. Digital particle image velocimetry (DPIV) measurements of the velocity and vorticity, together with laser induced fluorescence (LIF) visualizations, in a meridional plane revealed a toroidal structure with the appearance of an axisymmetric vortex breakdown bubble. Agreement was found between the measurements and numerical simulations of the axisymmetric Navier-Stokes equations. The results show that the flow in the effusive corner region is dominated by a Bödewadt-type spatially oscillatory boundary layer within the core region and a potential-like vortex boundary layer at large radii. The toroidal structure results from the interaction between these two boundary layers, leading to the roll up of a dominant shear layer within the Bödewadt structure, and does not develop from the columnar vortex itself.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 309-321 |
| Number of pages | 13 |
| Journal | Experiments in Fluids |
| Volume | 29 |
| Issue number | 4 |
| State | Published - Oct 2000 |
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ASJC Scopus subject areas
- Fluid Flow and Transfer Processes
- Computational Mechanics
- Mechanical Engineering
- Mechanics of Materials
Cite this
Evolution of an initially columnar vortex terminating normal to a no-slip wall. / Hirsa, A.; Lopez, Juan; Kim, S.
In: Experiments in Fluids, Vol. 29, No. 4, 10.2000, p. 309-321.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evolution of an initially columnar vortex terminating normal to a no-slip wall
AU - Hirsa, A.
AU - Lopez, Juan
AU - Kim, S.
PY - 2000/10
Y1 - 2000/10
N2 - The early evolution of an initially columnar vortex normal to a solid wall was examined. The vortex was generated by a pair of flaps in a water tank. Detrimental effects from the wall during the vortex generation were avoided by producing the vortex normal to a free surface and subsequently bringing a horizontal plate into contact with the surface. Digital particle image velocimetry (DPIV) measurements of the velocity and vorticity, together with laser induced fluorescence (LIF) visualizations, in a meridional plane revealed a toroidal structure with the appearance of an axisymmetric vortex breakdown bubble. Agreement was found between the measurements and numerical simulations of the axisymmetric Navier-Stokes equations. The results show that the flow in the effusive corner region is dominated by a Bödewadt-type spatially oscillatory boundary layer within the core region and a potential-like vortex boundary layer at large radii. The toroidal structure results from the interaction between these two boundary layers, leading to the roll up of a dominant shear layer within the Bödewadt structure, and does not develop from the columnar vortex itself.
AB - The early evolution of an initially columnar vortex normal to a solid wall was examined. The vortex was generated by a pair of flaps in a water tank. Detrimental effects from the wall during the vortex generation were avoided by producing the vortex normal to a free surface and subsequently bringing a horizontal plate into contact with the surface. Digital particle image velocimetry (DPIV) measurements of the velocity and vorticity, together with laser induced fluorescence (LIF) visualizations, in a meridional plane revealed a toroidal structure with the appearance of an axisymmetric vortex breakdown bubble. Agreement was found between the measurements and numerical simulations of the axisymmetric Navier-Stokes equations. The results show that the flow in the effusive corner region is dominated by a Bödewadt-type spatially oscillatory boundary layer within the core region and a potential-like vortex boundary layer at large radii. The toroidal structure results from the interaction between these two boundary layers, leading to the roll up of a dominant shear layer within the Bödewadt structure, and does not develop from the columnar vortex itself.
UR - http://www.scopus.com/inward/record.url?scp=0004198214&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0004198214&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0004198214
VL - 29
SP - 309
EP - 321
JO - Experiments in Fluids
JF - Experiments in Fluids
SN - 0723-4864
IS - 4
ER -