Skip to main content
Log in

Experimental study of pitching and plunging airfoils at low Reynolds numbers

  • Research Article
  • Published:
Experiments in Fluids Aims and scope Submit manuscript

Abstract

Measurements of the unsteady flow structure and force time history of pitching and plunging SD7003 and flat plate airfoils at low Reynolds numbers are presented. The airfoils were pitched and plunged in the effective angle of attack range of 2.4°–13.6° (shallow-stall kinematics) and −6° to 22° (deep-stall kinematics). The shallow-stall kinematics results for the SD7003 airfoil show attached flow and laminar-to-turbulent transition at low effective angle of attack during the down stroke motion, while the flat plate model exhibits leading edge separation. Strong Re-number effects were found for the SD7003 airfoil which produced approximately 25 % increase in the peak lift coefficient at Re = 10,000 compared to higher Re flows. The flat plate airfoil showed reduced Re effects due to leading edge separation at the sharper leading edge, and the measured peak lift coefficient was higher than that predicted by unsteady potential flow theory. The deep-stall kinematics resulted in leading edge separation that led to formation of a large leading edge vortex (LEV) and a small trailing edge vortex (TEV) for both airfoils. The measured peak lift coefficient was significantly higher (~50 %) than that for the shallow-stall kinematics. The effect of airfoil shape on lift force was greater than the Re effect. Turbulence statistics were measured as a function of phase using ensemble averages. The results show anisotropic turbulence for the LEV and isotropic turbulence for the TEV. Comparison of unsteady potential flow theory with the experimental data showed better agreement by using the quasi-steady approximation, or setting C(k) = 1 in Theodorsen theory, for leading edge–separated flows.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13

Similar content being viewed by others

References

  • Anderson JM, Streitlien K, Barrett DS, Triantafyllou MS (1998) Oscillating foils of high propulsive efficiency. J Fluid Mech 360:41–72

    Article  MathSciNet  MATH  Google Scholar 

  • Baik Y (2011) Unsteady force generation and vortex dynamics of pitching and plunging airfoils at low Reynolds number. PhD thesis, University of Michigan

  • Baik Y, Rausch JM, Bernal LP, Ol MV (2009) Experimental investigation of pitching and plunging airfoils at low Reynolds number between 1 × 104 and 6 × 104. AIAA 4030-734

  • Baik Y, Bernal LP, Granlund K, Ol MV (2012) Unsteady force generation and vortex dynamics of pitching and plunging aerofoils. J Fluid Mech 709:37–68. doi:10.1017/jfm.2012.318

    Article  Google Scholar 

  • Birch JM, Dickinson MH (2001) Spanwise flow and the attachment of the leading-edge vortex on insect wings. Nature 412:729–733

    Article  Google Scholar 

  • Birch JM, Dickson WB, Dickinson MH (2004) Force production and flow structure of the leading edge vortex on flapping wings. J Exp Biol 207:1063–1072

    Article  Google Scholar 

  • Bisplinghoff RL, Ashley H, Halfman RL (1996) Aeroelasticity. Dover, New York

    Google Scholar 

  • David L, Jardin T, Braud P, Farcy A (2011) Time-resolved scanning tomography PIV measurements around a flapping wing. Exp Fluids. doi:10.1007/s00348-011-1148-5

    Google Scholar 

  • Dickinson MH (1994) The effects of wing rotation on unsteady aerodynamic performance at low Reynolds numbers. J Exp Biol 192:179–206

    Google Scholar 

  • Dickinson MH, Gotz KG (1993) Unsteady aerodynamic performance on model wings at low Reynolds numbers. J Exp Biol 174:45–64

    Google Scholar 

  • Dickinson MH, Lehmann F, Sane SP (1999) Wing rotation and the aerodynamic basis of insect flight. Science 284:1954–1960

    Article  Google Scholar 

  • Ellington CP (1984) The aerodynamics of hovering insect flight III. Kinematics. Phil Trans R Soc Lond B 305:41–78

    Article  Google Scholar 

  • Ellington CP, van den Berg C, Willmott AP, Thomas ALR (1996) Leading-edge vortices in insect flight. Nature 384:626–630

    Article  Google Scholar 

  • Freymuth P (1988) Propulsive vortical signatures of plunging and pitching airfoils. AIAA J 26:881–883

    Article  Google Scholar 

  • Hover FS, Haugsdal O, Triantafyllou MS (2004) Forces on oscillating foils for propulsion and maneuvering. J Fluid Struct 19:37–47

    Article  Google Scholar 

  • Jones KD, Dohring CM, Platzer MF (1996) Wake structures behind plunging airfoil: a comparison of numerical and experimental results. AIAA 1996-0078

  • Kang C, Aono H, Baik, Y, Bernal LP, Shyy W (2012) Fluid dynamics of pitching and plunging flat plate at Reynolds number of O(104). AIAA J (accepted for publication)

  • Koochesfahani MM (1989) Vortical patterns in the wake of an oscillating airfoil. AIAA J 27(9):1200–1205

    Article  Google Scholar 

  • Lai JCS, Platzer MF (1999) Jet characteristics of a plunging airfoil. AIAA J 37:1529–1537

    Article  Google Scholar 

  • Lua KB, Lim TT, Yeo KS, Oo GY (2007) Wake-structure formation of a heaving two-dimensional elliptic airfoil. AIAA J 45:1571–1583

    Article  Google Scholar 

  • Maxworthy T (1979) Experiments on the Weis–Fogh mechanism of lift generation by insects in hovering flight part 1. Dynamics of the ‘fling’. J Fluid Mech 93:47–63

    Article  Google Scholar 

  • Maxworthy T (1981) The fluid dynamics of insect flight. Ann Rev Fluid Mech 13:329–350

    Article  Google Scholar 

  • McCroskey WJ (1981) The phenomenon of dynamic stall. NASA TM-81264

  • McCroskey WJ (1982) Unsteady airfoils. Ann Rev Fluid Mech 14:285–311

    Article  Google Scholar 

  • Ol M, McAuliffe BR, Hanff ES, Scholz U, Kaehler CH (2005) Comparison of laminar separation bubble measurements on a low Reynolds number airfoil in three facilities. AIAA 2005-5149

  • Ol M, Bernal LP, Kang C, Shyy W (2009) Shallow and deep dynamic stall for flapping low Reynolds number airfoils. Exp Fluids 46:883–901

    Article  Google Scholar 

  • Pines D, Bohorquez F (2006) Challenges facing future micro air vehicle development. J Aircr 43:290–305

    Article  Google Scholar 

  • Platzer M, Jones K, Young J, Lai J (2008) Flapping wing aerodynamics: progress and challenges. AIAA J 46:2136–2149

    Article  Google Scholar 

  • Read DA, Hover FS, Triantafyllou MS (2003) Effect of angle of attack profiles in flapping foil propulsion. J Fluid Struct 17:163–183

    Article  Google Scholar 

  • Rival D, Prangemeier T, Tropea C (2009) The influence of airfoil kinematics on the formation of leading-edge vortices in bio-inspired flight. Exp Fluids 46:823–833

    Article  Google Scholar 

  • Sane SP, Dickinson MH (2001) The control of flight force by a flapping wing: lift and drag production. J Exp Biol 204:2607–2626

    Google Scholar 

  • Selig MS, Guglielmo JJ, Broeren AP, Giguere P (1995) Summary of low speed airfoil data, vol 1. Soartech Aero, Virginia Beach

    Google Scholar 

  • Shyy W, Liu H (2007) Flapping wings and aerodynamics lift: the role of leading-edge vortices. AIAA J 45:2817–2819

    Article  Google Scholar 

  • Shyy W, Lian Y, Tang J, Viieru D, Liu H (2008) Aerodynamics of low Reynolds number flyers. Cambridge University Press, Cambridge

    Google Scholar 

  • Shyy W, Trizila P, Kang CK, Aono H (2009) Can tip vortices enhance lift of a flapping wing? AIAA J 47:289–293

    Article  Google Scholar 

  • Theodorsen T (1935) General theory of aerodynamic instability and the mechanism of flutter. NACA Report 496

  • Triantafyllou GS, Triantafyllou MS, Grosenbaugh MA (1992) Optimal thrust development in oscillating foils with applications to fish propulsion. J Fluid Struct 7:205–224

    Article  Google Scholar 

  • Young J, Lai JCS (2004) Oscillation frequency and amplitude effects on the wake of a plunging airfoil. AIAA J 42(10):2042–2052

    Article  Google Scholar 

Download references

Acknowledgments

This work has been supported in part by the Air Force Office of Scientific Research’s Multidisciplinary University Research Initiative (MURI) and by the Michigan/AFRL (Air Force Research Laboratory)/Boeing Collaborative Center in Aeronautical Sciences.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Yeon Sik Baik.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material (doc 1.25 MB)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Baik, Y.S., Bernal, L.P. Experimental study of pitching and plunging airfoils at low Reynolds numbers. Exp Fluids 53, 1979–1992 (2012). https://doi.org/10.1007/s00348-012-1401-6

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00348-012-1401-6

Keywords

Navigation