Hostname: page-component-8448b6f56d-wq2xx Total loading time: 0 Render date: 2024-04-19T02:01:48.213Z Has data issue: false hasContentIssue false

Vortex development on pitching plates with lunate and truncate planforms

Published online by Cambridge University Press:  04 September 2013

Colin Hartloper
Affiliation:
Department of Mechanical Engineering, University of Calgary, Calgary, AB T4N 1N4, Canada
David E. Rival*
Affiliation:
Department of Mechanical Engineering, University of Calgary, Calgary, AB T4N 1N4, Canada
*
Email address for correspondence: derival@ucalgary.ca

Abstract

The three-dimensional flow field and instantaneous forces are measured on pitching rectangular, lunate and truncate planforms of aspect-ratio four. The leading-edge vortex on the rectangular planform is compressed as it grows, and subsequently forms an arch-shaped vortex. For the lunate and truncate planforms, which both have identical spanwise leading-edge curvature but differ in planform area, outboard-directed convection of vorticity, rather than vortex stretching, mitigates arch-vortex formation. The vortical near wake that is formed by the planforms with spanwise leading-edge curvature is found to be strongly correlated with a favourable lift-to-drag ratio during the force-relaxation phase.

Type
Papers
Copyright
©2013 Cambridge University Press 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barnes, C. & Visbal, M. 2012 High-Ffidelity simulations of a hovering wing. AIAA Paper 2012-2699.Google Scholar
Eloy, C. 2013 On the best design for undulatory swimming. J. Fluid Mech. 717, 4889.Google Scholar
Gazzola, M., Van Rees, W. M. & Koumoutsakos, P. 2012 C-start: optimal start of larval fish. J. Fluid Mech. 698, 518.Google Scholar
Granlund, K., Ol, M. & Bernal, L. 2011 Experiments on pitching plates: force and flowfield measurements at low Reynolds numbers. AIAA Paper 2011-872.Google Scholar
Harbig, R. R., Sheridan, J. & Thompson, M. C. 2013 Reynolds number and aspect ratio effects on the leading-edge vortex for rotating insect wing planforms. J. Fluid Mech. 717, 166192.Google Scholar
Hartloper, C., Kinzel, M. & Rival, D. E. 2013 On the competition between leading-edge and tip-vortex growth for a pitching plate. Exp. Fluids 54, 1447.CrossRefGoogle Scholar
Kinzel, M., Wolf, M., Holzner, M., Luethi, B., Tropea, C. & Kinzelbach, W. 2011 Simultaneous two-scale 3D-PTV measurements in turbulence under the influence of system rotation. Exp. Fluids 51, 7582.CrossRefGoogle Scholar
Lentink, D. & Dickinson, M. H. 2009 Rotational accelerations stabilize leading edge vortices on revolving fly wings. J. Expl Biol. 212, 27052719.Google Scholar
Lighthill, M. J. 1969 Hydromechanics of aquatic animal propulsion. Annu. Rev. Fluid Mech. 1, 413446.CrossRefGoogle Scholar
Luethi, B., Tsinober, A. & Kinzelbach, W. 2005 Lagrangian measurement of vorticity dynamics in turbulent flow. J. Fluid Mech. 528, 87118.Google Scholar
Maxworthy, T. 2007 The formation and maintenance of a leading-edge vortex during the forward motion of an animal wing. J. Fluid Mech. 587, 471475.Google Scholar
Taira, K. & Colonius, T. 2009 Three-dimensional flows around low-aspect-ratio flat-plate wings at low Reynolds numbers. J. Fluid Mech. 623, 187207.Google Scholar
Triantafyllou, M. S. 2012 Survival hydrodynamics. J. Fluid Mech. 698, 14.Google Scholar
Visbal, M., Yilmaz, T. & Rockwell, D. 2013 Three-dimensional vortex formation on a heaving low-aspect-ratio wing: computations and experiments. J. Fluid Struct. 38, 5876.Google Scholar
Yilmaz, T. O. & Rockwell, D. 2012 Flow structure on finite-span wings due to pitch-up motion. J. Fluid Mech. 691, 518545.Google Scholar

Hartloper and Rival supplementary movie

Isosurfaces of z-vorticity (red) and xy-vorticity (green) on rectangular, lunate and truncate planforms from left to right.

Download Hartloper and Rival supplementary movie(Video)
Video 8.9 MB

Hartloper and Rival supplementary movie

Isosurfaces of inboard-directed (yellow) and outboard-directed (blue) z-velocity on rectangular, lunate and truncate planforms from left to right.

Download Hartloper and Rival supplementary movie(Video)
Video 6.9 MB