Imperial College London
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Professor Peter Bearman

Faculty of Engineering, Department of Aeronautics

Emeritus Professor in Aeronautics
 
 
 
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Contact

 

+44 (0)7936 449 701p.bearman Website

 
 
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Location

 

317ACity and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Clapperton:2018:10.1017/jfm.2018.399,
author = {Clapperton, B and Bearman, PW},
doi = {10.1017/jfm.2018.399},
journal = {Journal of Fluid Mechanics},
pages = {1157--1178},
title = {Control of circular cylinder flow using distributed passive jets},
url = {http://dx.doi.org/10.1017/jfm.2018.399},
volume = {848},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - A wind tunnel study has been carried out to investigate flow control around a hollow circular cylinder using passive jets driven by naturally occurring pressure differences. Flow enters the cylinder through spanwise holes along the stagnation line and exits through a spanwise distribution of holes at ±65 . The diameter of the entry and exit holes were 1 % and 0.5 % of the cylinder diameter, respectively. Reynolds numbers were at the upper end of the subcritical regime and ranged from 3×104 to 2.8×105 . Jet spacings of 10 % and 20 % of the cylinder diameter were investigated, and the ratio of the average jet exit velocity to the cross-flow velocity at the boundary layer edge was found to rise to approximately 0.35 and 0.4, respectively, above a Reynolds number of 1.5×105 . Findings based on using the surface oil flow technique revealed a repeating, organised cellular pattern downstream of adjacent jet exit holes consisting of a primary counter-rotating vortex pair structure, followed by a secondary weaker pair. Downstream of adjacent exit holes, and centred midway between them, there exists a separation bubble which delays final flow separation compared with the flow directly downstream of a jet. The variation in the angular position of boundary layer separation across the span had the effect of suppressing von Kármán vortex shedding. This resulted in a drag coefficient, at the upper end of the Reynolds-number range studied, 14.5 % lower than that found using trip wires to initiate boundary layer transition.
AU  - Clapperton,B
AU  - Bearman,PW
DO  - 10.1017/jfm.2018.399
EP  - 1178
PY  - 2018///
SN  - 0022-1120
SP  - 1157
TI  - Control of circular cylinder flow using distributed passive jets
T2  - Journal of Fluid Mechanics
UR  - http://dx.doi.org/10.1017/jfm.2018.399
UR  - https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/control-of-circular-cylinder-flow-using-distributed-passive-jets/C00A3A8DCE736091C43BA4CCDF2A4BE0
UR  - http://hdl.handle.net/10044/1/59010
VL  - 848
ER  -
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