| dc.contributor.author |
Shen, Lian |
|
| dc.contributor.author |
Zhang, Xiang |
|
| dc.contributor.author |
Yue, Dick K.P. |
|
| dc.contributor.author |
Triantafyllou, Michael S. |
|
| dc.date.accessioned |
2005-08-23T06:10:50Z |
|
| dc.date.available |
2005-08-23T06:10:50Z |
|
| dc.date.issued |
2003 |
|
| dc.identifier.uri |
http://hdl.handle.net/1721.1/25621 |
|
| dc.description.abstract |
Direct numerical simulation is used to study the turbulent flow over a smooth wavy
wall undergoing transverse motion in the form of a streamwise travelling wave. The
Reynolds number based on the mean velocity U of the external flow and wall motion
wavelength λ is 10 170; the wave steepness is 2πa/λ = 0.25 where a is the travelling
wave amplitude. A key parameter for this problem is the ratio of the wall motion
phase speed c to U, and results are obtained for c/U in the range of −1.0 to 2.0 at
0.2 intervals. For negative c/U, we find that flow separation is enhanced and a large
drag force is produced. For positive c/U, the results show that as c/U increases from
zero, the separation bubble moves further upstream and away from the wall, and is
reduced in strength. Above a threshold value of c/U ≈ 1, separation is eliminated;
and, relative to small- c/U cases, turbulence intensity and turbulent shear stress are
reduced significantly. The drag force decreases monotonically as c/U increases while the power required for the transverse motion generally increases for large c/U; the
net power input is found to reach a minimum at c/U ≈ 1.2 (for fixed U). The results
obtained in this study provide physical insight into the study of fish-like swimming
mechanisms in terms of drag reduction and optimal propulsive efficiency. |
en |
| dc.description.provenance |
Submitted by Tarun Agarwal (tarun_ag@mit.edu) on 2005-08-23T06:10:43Z
No. of bitstreams: 1
Triantafyllou_2003_Turbulent.pdf: 484296 bytes, checksum: 6840dbfce60928a7e5bf30a07a11a69d (MD5) |
en |
| dc.description.provenance |
Made available in DSpace on 2005-08-23T06:10:50Z (GMT). No. of bitstreams: 1
Triantafyllou_2003_Turbulent.pdf: 484296 bytes, checksum: 6840dbfce60928a7e5bf30a07a11a69d (MD5)
Previous issue date: 2003 |
en |
| dc.format.extent |
484296 bytes |
|
| dc.format.mimetype |
application/pdf |
|
| dc.language.iso |
en_US |
en |
| dc.publisher |
Cambridge University Press |
en |
| dc.rights |
Copyright: Cambridge University Press
This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder. |
|
| dc.subject |
Turbulence |
en |
| dc.subject |
reynolds number |
en |
| dc.subject |
numerical simulation |
en |
| dc.title |
Turbulent Flow over a Flexible Wall Undergoing a Streamwise Traveling Wavy Motion |
en |
| dc.type |
Article |
en |
| dc.identifier.citation |
Journal of Fluid Mechanics, 484, p.197-221 (2003) |
en |
