Abstract
In steady swirling flows in closed cylinders, it has been common to observe the transition to spirals of otherwise straight dye streaklines. This occurs in the regions where bubble type breakdown occurs but at a slightly lower Reynolds number. These regions are of particular interest for those seeking to explain the origins of vortex breakdown. The hitherto unexplained occurrence of the spiral streaklines, postulated previously to be due to non-axisymmetry of the flow, is found to be due to small offsets of the dye injection from the central axis. The important implications of this finding are that (i) non-axisymmetry is not a necessary route to bubble-type vortex breakdown, and (ii) that flows displaying spiral streaklines may be still sufficiently axisymmetrical for comparison with numerical and theoretical treatments of the breakdown phenomenon.
| Original language | English |
|---|---|
| Pages (from-to) | 3126-3128 |
| Number of pages | 3 |
| Journal | Physics of Fluids |
| Volume | 7 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 1 Jan 1995 |
Cite this
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Spiral streaklines in pre-vortex breakdown regions of axisymmetric swirling flows. / Hourigan, K.; Graham, L. J.W.; Thompson, M. C.
In: Physics of Fluids, Vol. 7, No. 12, 01.01.1995, p. 3126-3128.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Spiral streaklines in pre-vortex breakdown regions of axisymmetric swirling flows
AU - Hourigan, K.
AU - Graham, L. J.W.
AU - Thompson, M. C.
PY - 1995/1/1
Y1 - 1995/1/1
N2 - In steady swirling flows in closed cylinders, it has been common to observe the transition to spirals of otherwise straight dye streaklines. This occurs in the regions where bubble type breakdown occurs but at a slightly lower Reynolds number. These regions are of particular interest for those seeking to explain the origins of vortex breakdown. The hitherto unexplained occurrence of the spiral streaklines, postulated previously to be due to non-axisymmetry of the flow, is found to be due to small offsets of the dye injection from the central axis. The important implications of this finding are that (i) non-axisymmetry is not a necessary route to bubble-type vortex breakdown, and (ii) that flows displaying spiral streaklines may be still sufficiently axisymmetrical for comparison with numerical and theoretical treatments of the breakdown phenomenon.
AB - In steady swirling flows in closed cylinders, it has been common to observe the transition to spirals of otherwise straight dye streaklines. This occurs in the regions where bubble type breakdown occurs but at a slightly lower Reynolds number. These regions are of particular interest for those seeking to explain the origins of vortex breakdown. The hitherto unexplained occurrence of the spiral streaklines, postulated previously to be due to non-axisymmetry of the flow, is found to be due to small offsets of the dye injection from the central axis. The important implications of this finding are that (i) non-axisymmetry is not a necessary route to bubble-type vortex breakdown, and (ii) that flows displaying spiral streaklines may be still sufficiently axisymmetrical for comparison with numerical and theoretical treatments of the breakdown phenomenon.
UR - http://www.scopus.com/inward/record.url?scp=0028993095&partnerID=8YFLogxK
U2 - 10.1063/1.868620
DO - 10.1063/1.868620
M3 - Article
VL - 7
SP - 3126
EP - 3128
JO - Physics of Fluids
JF - Physics of Fluids
SN - 1089-7666
IS - 12
ER -