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Reappearance of azimuthal waves in turbulent Taylor–Couette flow at large aspect ratio
Velocity field data were acquired for Taylor–Couette flow in the annular gap between an inner rotating cylinder and a stationary concentric outer cylinder using particle image velocimetry (PIV) in a meridional plane of the annulus. Data were acquired for several rotational Reynolds numbers with the...
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Published in: | Chemical engineering science 2005-10, Vol.60 (20), p.5555-5568 |
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Main Authors: | , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Velocity field data were acquired for Taylor–Couette flow in the annular gap between an inner rotating cylinder and a stationary concentric outer cylinder using particle image velocimetry (PIV) in a meridional plane of the annulus. Data were acquired for several rotational Reynolds numbers with the ratio of the rotational and critical Reynolds numbers ranging from 6 to 200, corresponding to flow states ranging from laminar wavy Taylor vortex flow to turbulent Taylor vortex flow. Spatial correlations of velocity fluctuations were found to exhibit a sharp decrease as
R
, the ratio of Reynolds number to the critical Reynolds number, increases from 16, indicating the disappearance of azimuthal waves and the onset of turbulence, reaching a minimum at
R
=
18
. However, correlation lengths subsequently increase with increasing
R
, displaying a secondary peak from
20
⩽
R
⩽
38
, suggesting the reappearance of azimuthal waves. The reemergence of azimuthal waves was confirmed through other methods including analysis of the axial velocity. At still higher Reynolds numbers, correlation lengths decay once again. The magnitude and Reynolds number associated with the secondary peak in the fluctuation velocity correlations were found to be dependent on the location of the basis point used in the calculations. Specifically, correlation lengths were longest near the outer cylinder in the inflow boundary and near the inner cylinder in the outflow boundary. This was shown to be due to the spatial dependence of Reynolds stresses in turbulent Taylor–Couette flow. |
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ISSN: | 0009-2509 1873-4405 |
DOI: | 10.1016/j.ces.2005.05.024 |