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On the persistence of memory: do initial conditions impact vortex formation?

Published online by Cambridge University Press:  01 November 2013

Jochen Kriegseis
Affiliation:
Department of Mechanical Engineering, University of Calgary, Calgary, T2N 1N4, Canada
Matthias Kinzel
Affiliation:
Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
David E. Rival*
Affiliation:
Department of Mechanical Engineering, University of Calgary, Calgary, T2N 1N4, Canada
*
Email address for correspondence: [email protected]

Abstract

An investigation into redistribution of vorticity for rapidly accelerating plates with varying kinematics and initial conditions has been performed. Both three-dimensional particle tracking velocimetry and direct force measurements were applied simultaneously. The effective velocity of the feeding shear layer has been identified as the appropriate characteristic velocity rather than the commonly used plunge or free stream velocity. Based on this new normalization for circulation, it has been demonstrated that the existence of initial boundary-layer vorticity on the plunging plate – at least in the near-midplane region – does not contribute to the eventual vortex formation process. In accordance with the literature, however, the tip vortex positioning relative to the plate surface has been identified as an important contributor in the overall force production, particularly once the plate acceleration has ceased.

Type
Papers
Copyright
©2013 Cambridge University Press 

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References

Afgan, I., Benhamadouche, S., Han, X., Sagaut, P. & Laurence, D. 2013 Flow over a flat plate with uniform inlet and incident coherent gusts. J. Fluid Mech. 720, 457485.Google Scholar
Baik, Y., Bernal, L., Granlund, K. & Ol, M. 2012 Unsteady force generation and vortex dynamics of pitching and plunging aerofoils. J. Fluid Mech. 709, 3768.CrossRefGoogle Scholar
Buchholz, J. H. J., Green, M. A. & Smits, A. J. 2011 Scaling the circulation shed by a pitching panel. J. Fluid Mech. 688, 591601.Google Scholar
Feng, Y., Goree, J. & Liu, B. 2011 Errors in particle tracking velocimetry with high-speed cameras. Rev. Sci. Instrum. 82, 053707.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
Gendrich, C. P. 1999 Dynamic stall of rapidly pitching airfoils: MTV experiments and Navier–Stokes simulations. PhD thesis, Michigan State University.Google Scholar
Hartloper, C., Kinzel, M. & Rival, D. 2012 On the competition between leading-edge and tip-vortex growth for a pitching plate. Exp. Fluids 54, 1447.Google Scholar
Jardin, T., Farcy, A. & David, L. 2012 Three-dimensional effects in hovering flapping flight. J. Fluid Mech. 702, 102125.Google Scholar
Jones, A. R. & Babinsky, H. 2010 Unsteady lift generation on rotating wings at low Reynolds numbers. J. Aircraft 47 (3), 10131021.Google Scholar
Kim, D. & Gharib, M. 2010 Experimental study of three-dimensional vortex structures in translating and rotating plates. Exp. Fluids 49, 329339.Google Scholar
Kim, D. & Gharib, M. 2011 Flexibility effects on vortex formation of translating plates. J. Fluid Mech. 677, 255271.CrossRefGoogle Scholar
Koumoutsakos, P. & Shiels, D. 1996 Simulations of the viscous flow normal to an impulsively started and uniformly accelerated flat plate. J. Fluid Mech. 328, 177227.CrossRefGoogle Scholar
Lüthi, B., Tsinober, A. & Kinzelbach, W. 2005 Lagrangian measurement of vorticity dynamics in turbulent flow. J. Fluid Mech. 528, 87118.Google Scholar
Morton, B. R. 1984 The generation and decay of vorticity. Geophys. Astrophys. Fluid Dyn. 28 (3–4), 277308.Google Scholar
Ol, M. V., Altman, A., Eldredge, J. D., Garmann, D. J. & Lian, Y. 2010 Résumé of the AIAA FDTC Low Reynolds Number Discussion Group’s canonical cases. In Proceedings of the 48th AIAA Aerospace Sciences Meeting, 4–7 January 2010, Orlando, FL, USA. AIAA 2010-1085.Google Scholar
Ringuette, M. J., Milano, M. & Gharib, M. 2007 Role of the tip vortex in the force generation of low-aspect-ratio normal flat plates. J. Fluid Mech. 581, 453468.Google Scholar
Roshko, A. 1954 On the drag and shedding frequency of two-dimensional bluff bodies. NACA Tech. Rep. TN 3169.Google Scholar
Sattari, P., Rival, D. E., Martinuzzi, R. J. & Tropea, C. 2012 Growth and separation of a start-up vortex from a two-dimensional shear layer. Phys. Fluids 24, 107102.Google Scholar
Weymouth, G. D. & Triantafyllou, M. S. 2012 Global vorticity shedding for a shrinking cylinder. J. Fluid Mech. 702, 470487.CrossRefGoogle Scholar
White, F. M. 1991 Viscous Fluid Flow, 2nd edn, pp. 137143. McGraw-Hill.Google Scholar
Wibawa, M. S., Steele, S. C., Dahl, J. M., Rival, D. E., Weymouth, G. D. & Triantafyllou, M. S. 2012 Global vorticity shedding for a vanishing wing. J. Fluid Mech. 695, 112134.CrossRefGoogle Scholar
Yilmaz, T., Ol, M. & Rockwell, D. 2010 Scaling of flow separation on a pitching low aspect ratio plate. J. Fluids Struct. 26, 10341041.CrossRefGoogle 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