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Aerodynamics of a wing in turbulent bluff body wakes

Published online by Cambridge University Press:  03 March 2022

Z. Zhang Open the ORCID record for Z. Zhang [Opens in a new window] ,
Z. Wang Open the ORCID record for Z. Wang [Opens in a new window]  and
I. Gursul Open the ORCID record for I. Gursul [Opens in a new window]
Z. Zhang
Affiliation:
Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK
Z. Wang
Affiliation:
Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK
I. Gursul*
Affiliation:
Department of Mechanical Engineering, University of Bath, Bath BA2 7AY, UK
*
† Email address for correspondence: ensiag@bath.ac.uk
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Abstract

The aerodynamics of a stationary wing in a turbulent wake are investigated. Force and velocity measurements are used to describe the unsteady flow. Various wakes are studied with different dominant frequencies and length scales. In contrast to the pre-stall angles of attack, the time-averaged lift increases substantially at post-stall angles of attack as the wing interacts with the von Kármán vortex street and experiences temporal variations of the effective angle of attack. At an optimal offset distance from the wake centreline, the time-averaged lift becomes maximum despite of small amplitude oscillations in the effective angle of attack. The stall angle of attack can reach 20° and the maximum lift coefficient can reach 64 % higher than that in the freestream. Whereas large velocity fluctuations at the wake centreline cause excursions into the fully attached and separated flows during the cycle, small-amplitude oscillations at the optimal location result in periodic shedding of leading edge vortices. These vortices may produce large separation bubbles with reattachment near the trailing-edge. Vorticity roll-up, strength and size of the vortices increase with increasing wavelength and period of the von Kármán vortex street, which also coincides with an increase in the spanwise length scale of the incident wake, and all contribute to the remarkable increase in lift.

JFM classification

Aerodynamics: Aerodynamics Vortex Flows: Vortex Flows
Type
JFM Papers
Information
Journal of Fluid Mechanics , Volume 937 , 25 April 2022 , A37
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Copyright
© The Author(s), 2022. Published by Cambridge University Press

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References

REFERENCES

Alexander, G. 2021 Panel method for NACA XXXX aerofoils. MATLAB Central File Exchange. Available at: https://www.mathworks.com/matlabcentral/fileexchange/52771-panel-method-for-naca-xxx-aerofoils. Accessed November 16, 2021.Google Scholar
Allen, J. & Smits, A. 2001 Energy harvesting eel. J. Fluids Struct. 15 (3–4), 629–640.CrossRefGoogle Scholar
Bangash, Z.A., Sanchez, R.P. & Ahmed, A. 2006 Aerodynamics of formation flight. J. Aircraft 43, 907–912.CrossRefGoogle Scholar
Barnes, C.J. & Visbal, M.R. 2020 Angle of attack and core size effects on transitional vortical-gust–airfoil interactions. AIAA J. 58 (7), 2881–2898.CrossRefGoogle Scholar
Bendat, J. & Piersol, A. 1986 Random Data Analysis and Measurement Procedures. Hoboken.Google Scholar
Boschitsch, B.M., Dewey, P.A. & Smits, A.J. 2014 Propulsive performance of unsteady tandem hydrofoils in an in-line configuration. Phys. Fluids 26 (5), 051901.CrossRefGoogle Scholar
Bull, S., Chiereghin, N., Gursul, I. & Cleaver, D.J. 2021 Unsteady aerodynamics of a plunging airfoil in transient motion. J. Fluids Struct. 103, 103288.CrossRefGoogle Scholar
Chen, J.M. & Choa, C. 1999 Freestream disturbance effects on an airfoil pitching at constant rate. J. Aircraft 36 (3), 507–514.CrossRefGoogle Scholar
Choi, J., Colonius, T. & Williams, D.R. 2015 Surging and plunging oscillations of an airfoil at low Reynolds number. J. Fluid Mech. 763, 237–253.CrossRefGoogle Scholar
Cleaver, D.J., Wang, Z., Gursul, I. & Visbal, M.R. 2011 Lift enhancement by means of small-amplitude airfoil oscillations at low Reynolds numbers. AIAA J. 49 (9), 2018–2033.CrossRefGoogle Scholar
Durgesh, V., Padilla, R., Garcia, E.N. & Johari, H. 2019 Impact of coherent structures on aerodynamics performance at low Reynolds numbers. AIAA SciTech 2019 Forum, San Diego, California, AIAA Paper 2019-0847.Google Scholar
Ekaterinaris, J. & Platzer, M. 1998 Computational prediction of airfoil dynamic stall. Prog. Aerosp. Sci. 33 (11–12), 759–846.CrossRefGoogle Scholar
Greenblatt, D. & Wygnanski, I.J. 2000 The control of flow separation by periodic excitation. Prog. Aerosp. Sci. 36 (7), 487–545.CrossRefGoogle Scholar
Gursul, I. & Ho, C.M. 1992 High aerodynamic loads on an airfoil submerged in an unsteady stream. AIAA J. 30 (4), 1117–1119.CrossRefGoogle Scholar
Gursul, I., Lin, H. & Ho, C.M. 1994 Effects of time scales on lift of airfoils in an unsteady stream. AIAA J. 32, 797–801.CrossRefGoogle Scholar
Gursul, I. & Rockwell, D. 1990 Vortex street impinging upon an elliptical leading edge. J. Fluid Mech. 211, 211–242.CrossRefGoogle Scholar
Hayakawa, M. & Hussain, F. 1989 Three-dimensionality of organized structures in a plane turbulent wake. J. Fluid Mech. 206, 375–404.CrossRefGoogle Scholar
Hodson, H.P. & Howell, R.J. 2005 Blade-row interactions, transition, and high-lift aerofoils in low-pressure turbines. Annu. Rev. Fluid Mech. 37, 71–98.CrossRefGoogle Scholar
Hoffmann, J.A. 1991 Effects of freestream turbulence on the performance characteristics of an airfoil. AIAA J. 29 (9), 1353–1354.CrossRefGoogle Scholar
Jones, R., Cleaver, D.J. & Gursul, I. 2015 Aerodynamics of biplane and tandem wings at low Reynolds numbers. Exp. Fluids 56, 124.CrossRefGoogle Scholar
Kay, N.J., Richards, P.J. & Sharma, R.N. 2020 Influence of turbulence on cambered and symmetrical airfoils at low Reynolds numbers. AIAA J. 58 (5), 1913–1925.CrossRefGoogle Scholar
Kaykayoglu, R. & Rockwell, D. 1985 Vortices incident upon a leading edge: instantaneous pressure fields. J. Fluid Mech. 156, 439–461.CrossRefGoogle Scholar
Knight, M. & Wenzinger, C.J. 1929 Wind tunnel tests on a series of wing models through a large angle of attack range. Part I: force tests. In Annual Report – National Advisory Committee for Aeronautics, NACA Tech. Rep. 317.Google Scholar
Lefebvre, J.N. & Jones, A.R. 2019 Experimental investigation of airfoil performance in the wake of a circular cylinder. AIAA J. 57 (7), 2808–2818.CrossRefGoogle Scholar
Lehmann, F.O. 2009 Wing–wake interaction reduces power consumption in insect tandem wings. Exp. Fluids 46 (5), 765–775.CrossRefGoogle Scholar
Li, L. & Hearst, R.J. 2021 The influence of freestream turbulence on the temporal pressure distribution and lift of an airfoil. J. Wind Engng Ind. Aerodyn. 209, 104456.CrossRefGoogle Scholar
Lissaman, P.B. & Shollenberger, C.A. 1970 Formation flight of birds. Science 168 (3934), 1003–1005.CrossRefGoogle Scholar
Mckinney, W. & Delaurier, J. 1981 Wingmill: an oscillating-wing windmill. J. Energy 5 (2), 109–115.CrossRefGoogle Scholar
Moffat, R.J. 1985 Using uncertainty analysis in the planning of an experiment. J. Fluids Engng 107 (2), 173–178.CrossRefGoogle Scholar
Oudheusden, B.W.V., Scarano, F., Hinsberg, N.P.V. & Watt, D.W. 2005 Phase-resolved characterization of vortex shedding in the near wake of a square-section cylinder at incidence. Exp. Fluids 39 (1), 86–98.CrossRefGoogle Scholar
Peng, D. & Gregory, J.W. 2015 Vortex dynamics during blade-vortex interactions. Phys. Fluids 27 (5), 053104.CrossRefGoogle Scholar
Qian, Y., Wang, Z. & Gursul, I. 2021 Interaction of quasi-two-dimensional vortical gusts with swept and unswept wings. In AIAA Science and Technology Forum and Exposition (SciTech 2021), AIAA Paper 2021-1935.CrossRefGoogle Scholar
Ravi, S., Watkins, S., Watmuff, J., Massey, K., Peterson, P. & Marino, M. 2012 Influence of large-scale freestream turbulence on the performance of a thin airfoil. AIAA J. 50 (11), 2448–2459.CrossRefGoogle Scholar
Rockwell, D. 1998 Vortex-body interactions. Annu. Rev. Fluid Mech. 30 (1), 199–229.CrossRefGoogle Scholar
Rockwell, D. & Knisely, C. 1979 The organized nature of flow impingement upon a corner. J. Fluid Mech. 93 (3), 413–432.CrossRefGoogle Scholar
Rojratsirikul, P., Genc, M.S., Wang, Z. & Gursul, I. 2011 Flow-induced vibrations of low aspect ratio rectangular membrane wings. J. Fluids Struct. 27, 1296–1309.CrossRefGoogle Scholar
Sandham, N.D. 2008 Transitional separation bubbles and unsteady aspects of aerofoil stall. Aeronaut. J. 112, 395–404.CrossRefGoogle Scholar
Scharpf, D.F. & Mueller, T.J. 1992 Experimental study of a low Reynolds number tandem airfoil configuration. J. Aircraft 29 (2), 231–236.CrossRefGoogle Scholar
Seifert, A., Bachar, T., Koss, D., Shepshelovich, M. & Wygnanski, I. 1993 Oscillatory blowing: a tool to delay boundary-layer separation. AIAA J. 31 (11), 2052–2060.CrossRefGoogle Scholar
Seifert, A., Darabi, A. & Wyganski, I. 1996 Delay of airfoil stall by periodic excitation. J. Aircraft 33 (4), 691–698.CrossRefGoogle Scholar
Turhan, B., Wang, Z. & Gursul, I. 2022 Coherence of unsteady wake of periodically plunging airfoil. J. Fluid Mech. (accepted).Google Scholar
Wang, Z. & Gursul, I. 2012 Unsteady characteristics of inlet vortices. Exp. Fluids 53 (4), 1015–1032.CrossRefGoogle Scholar
Wilder, M. & Telionis, D. 1998 Parallel blade–vortex interaction. J. Fluids Struct. 12 (7), 801–838.CrossRefGoogle Scholar
Wu, J.Z., Lu, X.Y., Denny, A.G., Fan, M. & Wu, J.M. 1998 Post-stall flow control on an airfoil by local unsteady forcing. J. Fluid Mech. 371, 21–58.CrossRefGoogle Scholar
Xfoil 2021 Available at: https://web.mit.edu/drela/Public/web/xfoil/. Accessed 10 June 2021.Google Scholar
Zhang, Z., Wang, Z. & Gursul, I. 2020 Lift enhancement of a stationary wing in a wake. AIAA J. 58 (11), 4613–4619.CrossRefGoogle Scholar
Ziada, S. & Rockwell, D. 1982 Vortex–leading edge interaction. J. Fluid Mech. 118, 79–107.CrossRefGoogle Scholar