Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-09T06:11:03.717Z Has data issue: false hasContentIssue false

The influence of wing morphology on the three-dimensional flow patterns of a flapping wing at bird scale

Published online by Cambridge University Press:  04 March 2015

William Thielicke*
Affiliation:
Department of Ocean Ecosystems, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands Department of Biomimetics, Bremen University of Applied Sciences, Neustadtswall 30, 28199 Bremen, Germany Biomimetics-Innovation-Centre, Bremen University of Applied Sciences, Neustadtswall 30, 28199 Bremen, Germany
Eize J. Stamhuis
Affiliation:
Department of Ocean Ecosystems, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands Department of Biomimetics, Bremen University of Applied Sciences, Neustadtswall 30, 28199 Bremen, Germany
*
Email address for correspondence: [email protected]

Abstract

The effect of airfoil design parameters, such as airfoil thickness and camber, are well understood in steady-state aerodynamics. But this knowledge cannot be readily applied to the flapping flight in insects and birds: flow visualizations and computational analyses of flapping flight have identified that in many cases, a leading-edge vortex (LEV) contributes substantially to the generation of aerodynamic force. In flapping flight, very high angles of attack and partly separated flow are common features. Therefore, it is expected that airfoil design parameters affect flapping wing aerodynamics differently. Existing studies have focused on force measurements, which do not provide sufficient insight into the dominant flow features. To analyse the influence of wing morphology in slow-speed bird flight, the time-resolved three-dimensional flow field around different flapping wing models in translational motion at a Reynolds number of $22\,000<\mathit{Re}<26\,000$ was studied. The effect of several Strouhal numbers ($0.2<\mathit{St}<0.4$), camber and thickness on the flow morphology and on the circulation was analysed. A strong LEV was found on all wing types at high $\mathit{St}$. The vortex is stronger on thin wings and enhances the total circulation. Airfoil camber decreases the strength of the LEV, but increases the total bound circulation at the same time, due to an increase of the ‘conventional’ bound circulation at the inner half of the wing. The results provide new insights into the influence of airfoil shape on the LEV and force generation at low $\mathit{Re}$. They contribute to a better understanding of the geometry of vertebrate wings, which seem to be optimized to benefit from LEVs in slow-speed flight.

Type
Papers
Copyright
© 2015 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

Altshuler, D. L., Dudley, R. & Ellington, C. P. 2004 Aerodynamic forces of revolving hummingbird wings and wing models. J. Zool. 264 (4), 327332.Google Scholar
Anderson, J. D. 2007 Fundamentals of Aerodynamics, 4th edn. McGraw-Hill.Google Scholar
Bachmann, T. W.2010 Anatomical, morphometrical and biomechanical studies of barn owls’ and pigeons’ wings. PhD thesis, RWTH Aachen.Google Scholar
van den Berg, C. & Ellington, C. P. 1997 The three-dimensional leading-edge vortex of a ‘hovering’ model hawkmoth. Phil. Trans. R. Soc. Lond. B 352 (1351), 329340.Google Scholar
Biesel, W., Butz, H. & Nachtigall, W. 1985 Erste messungen der flügelgeometrie bei frei gleitfliegenden haustauben (Columba livia var. domestica) unter benutzung neu ausgearbeiteter verfahren der windkanaltechnik und der stereophotogrammetrie. Biona Rep. 3, 139160.Google Scholar
Bilo, D. 1972 Flugbiophysik von kleinvögeln. J. Compar. Physiol. 76 (4), 426437.Google Scholar
Birch, J. M., Dickson, W. B. & Dickinson, M. H. 2004 Force production and flow structure of the leading edge vortex on flapping wings at high and low Reynolds numbers. J. Expl Biol. 207 (7), 10631072.Google Scholar
Bomphrey, R. J., Lawson, N. J., Harding, N. J., Taylor, G. K. & Thomas, A. L. R. 2005 The aerodynamics of Manduca sexta: digital particle image velocimetry analysis of the leading-edge vortex. J. Expl Biol. 208 (6), 10791094.Google Scholar
Cabral, B. & Leedom, L. C. 1993 Imaging vector fields using line integral convolution. In Proceedings of the 20th Annual Conference on Computer Graphics and Interactive Techniques, New York, pp. 263270. ACM.Google Scholar
Chang, Y.-H., Ting, S.-C., Su, J.-Y., Soong, C.-Y. & Yang, J.-T. 2013 Ventral-clap modes of hovering passerines. Phys. Rev. E 87 (2), 022707.CrossRefGoogle ScholarPubMed
Dickinson, M. H. & Gotz, K. G. 1993 Unsteady aerodynamic performance of model wings at low Reynolds numbers. J. Expl Biol. 174 (1), 4564.CrossRefGoogle Scholar
Dubief, Y. & Delcayre, F. 2000 On coherent-vortex identification in turbulence. J. Turbul. 1, N11.Google Scholar
Ellington, C. P. 1984 The aerodynamics of hovering insect flight. III. Kinematics. Phil. Trans. R. Soc. Lond. B 305 (1122), 4178.Google Scholar
Ellington, C. P., van den Berg, C., Willmott, A. P. & Thomas, A. L. R. 1996 Leading-edge vortices in insect flight. Nature 384 (6610), 626630.CrossRefGoogle Scholar
Friedel, A. & Kähler, C. 2012 Measuring and analyzing the birds flight. In Proceedings of the International Micro Air Vehicle Conference and Flight Competition 2012, IMAV 2012 Organization Committee.Google Scholar
Garcia, D. 2010 Robust smoothing of gridded data in one and higher dimensions with missing values. Comput. Stat. Data Anal. 54 (4), 11671178.Google Scholar
Haller, G. 2005 An objective definition of a vortex. J. Fluid Mech. 525, 126.CrossRefGoogle Scholar
Hubel, T. Y. & Tropea, C. 2009 Experimental investigation of a flapping wing model. Exp. Fluids 46 (5), 945961.CrossRefGoogle Scholar
Hubel, T. Y. & Tropea, C. 2010 The importance of leading edge vortices under simplified flapping flight conditions at the size scale of birds. J. Expl Biol. 213 (11), 19301939.Google Scholar
Hunt, J. C. R., Wray, A. A. & Moin, P. 1988 Eddies, streams, and convergence zones in turbulent flows. In Studying Turbulence Using Numerical Simulation Databases, 2, pp. 193–208; doi:10.1017/S002211200800236X.Google Scholar
Kunz, P. J.2003 Aerodynamics and design for ultra-low Reynolds number flight. PhD thesis, Stanford University.Google Scholar
Lentink, D. & Dickinson, M. H. 2009 Rotational accelerations stabilize leading edge vortices on revolving fly wings. J. Expl Biol. 212 (16), 27052719.Google Scholar
Lilienthal, O. 1889 Der Vogelflug als Grundlage der Fliegekunst. R. Gaertners Verlagsbuchhandlung.Google Scholar
Liu, H., Ellington, C. P., Kawachi, K., Van Den Berg, C. & Willmott, A. P. 1998 A computational fluid dynamic study of hawkmoth hovering. J. Expl Biol. 201 (4), 461477.CrossRefGoogle ScholarPubMed
Lu, Y. & Shen, G. X. 2008 Three-dimensional flow structures and evolution of the leading-edge vortices on a flapping wing. J. Expl Biol. 211 (8), 12211230.Google Scholar
Muijres, F. T., Johansson, L. C., Barfield, R., Wolf, M., Spedding, G. R. & Hedenstroem, A. 2008 Leading-edge vortex improves lift in slow-flying bats. Science 319 (5867), 12501253.Google Scholar
Muijres, F. T., Johansson, L. C. & Hedenstroem, A. 2012 Leading edge vortex in a slow-flying passerine. Biol. Lett. 8 (4), 554557.Google Scholar
Norberg, U. M. 1990 Vertebrate Flight. Springer.CrossRefGoogle Scholar
Okamoto, M., Yasuda, K. & Azuma, A. 1996 Aerodynamic characteristics of the wings and body of a dragonfly. J. Expl Biol. 199 (2), 281294.Google Scholar
Poelma, C., Dickson, W. & Dickinson, M. 2006 Time-resolved reconstruction of the full velocity field around a dynamically-scaled flapping wing. Exp. Fluids 41 (2), 213225.Google Scholar
Ramesh, K., Ke, J., Gopalarathnam, A. & Edwards, J. R.2012 Effect of airfoil shape and Reynolds number on leading edge vortex shedding in unsteady flows. In 30th AIAA Applied Aerodynamics Conference, New Orleans, Louisiana.Google Scholar
Rival, D. E., Kriegseis, J., Schaub, P., Widmann, A. & Tropea, C. 2014 Characteristic length scales for vortex detachment on plunging profiles with varying leading-edge geometry. Exp. Fluids 55 (1), 18.Google Scholar
Robinson, S. K., Kline, S. J. & Spalart, P. R.1989 A review of quasi-coherent structures in a numerically simulated turbulent boundary layer. NASA Tech. Rep. TM-102191.Google Scholar
Rosén, M., Spedding, G. R. & Hedenstroem, A. 2004 The relationship between wingbeat kinematics and vortex wake of a thrush nightingale. J. Expl Biol. 207 (24), 42554268.CrossRefGoogle ScholarPubMed
Ruck, S. & Oertel, H. Jr. 2010 Fluid–structure interaction simulation of an avian flight model. J. Expl Biol. 213 (24), 41804192.Google Scholar
Shyy, W., Lian, Y., Tang, J., Viieru, D. & Liu, H. 2008 Aerodynamics of Low Reynolds Number Flyers. Cambridge University Press.Google Scholar
Spedding, G. R., Rayner, J. M. V. & Pennycuick, C. J. 1984 Momentum and energy in the wake of a pigeon (Columba livia) in slow flight. J. Expl Biol. 111 (1), 81102.Google Scholar
Srygley, R. B. & Thomas, A. L. R. 2002 Unconventional lift-generating mechanisms in free-flying butterflies. Nature 420 (6916), 660664.Google Scholar
Swartz, S. M., Groves, M. S., Kim, H. D. & Walsh, W. R. 1996 Mechancial properties of bat wing membrane skin. J. Zool. 239 (2), 357378.CrossRefGoogle Scholar
Taylor, G. K., Nudds, R. L. & Thomas, A. L. R. 2003 Flying and swimming animals cruise at a Strouhal number tuned for high power efficiency. Nature 425 (6959), 707711.Google Scholar
Thielicke, W. & Stamhuis, E. J. 2014 PIVlab – towards user-friendly, affordable and accurate digital particle image velocimetry in MATLAB. J. Open Res. Softw. 2 (1), e30.Google Scholar
Tian, X., Iriarte-Diaz, J., Middleton, K., Galvao, R., Israeli, E., Roemer, A., Sullivan, A., Song, A., Swartz, S. & Breuer, K. 2006 Direct measurements of the kinematics and dynamics of bat flight. Bioinspir. Biomim. 1 (4), S10.Google Scholar
Tobalske, B. W. 2007 Biomechanics of bird flight. J. Expl Biol. 210 (18), 31353146.Google Scholar
Unal, M. F., Lin, J.-C. & Rockwell, D. 1997 Force prediction by PIV imaging: a momentum-based approach. J. Fluids Struct. 11 (8), 965971.Google Scholar
Usherwood, J. R. 2009 Inertia may limit efficiency of slow flapping flight, but mayflies show a strategy for reducing the power requirements of loiter. Bioinspir. Biomim. 4 (1), 015003.Google Scholar
Usherwood, J. R. & Ellington, C. P. 2002 The aerodynamics of revolving wings. I. Model hawkmoth wings. J. Expl Biol. 205 (11), 15471564.CrossRefGoogle ScholarPubMed
Vandenberghe, N., Zhan, J. & Childress, S. 2004 Symmetry breaking leads to forward flapping flight. J. Fluid Mech. 506, 147155.CrossRefGoogle Scholar
Videler, J. J. 2005 Avian Flight. Oxford University Press.Google Scholar
Videler, J. J., Stamhuis, E. J. & Povel, G. D. E. 2004 Leading-edge vortex lifts swifts. Science 306 (5703), 19601962.Google Scholar
Wang, Z. J. 2005 Dissecting insect flight. Annu. Rev. Fluid Mech. 37 (1), 183210.Google Scholar
Wang, Z. J., Birch, J. M. & Dickinson, M. H. 2004 Unsteady forces and flows in low Reynolds number hovering flight: two-dimensional computations vs robotic wing experiments. J. Expl Biol. 207 (3), 449460.Google Scholar
Warrick, D. R., Tobalske, B. W. & Powers, D. R. 2005 Aerodynamics of the hovering hummingbird. Nature 435 (7045), 10941097.Google Scholar