Log in

The interaction between turbulent separation bubble breathing and wall pressure on a 2D wing

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

Abstract

This investigation characterized the relation between the breathing motion and wall-pressure fluctuations for a turbulent separation upstream of the trailing edge of a two-dimensional wing with NACA 4418 profile. The experiments were conducted at a freestream velocity U = 10.2 m/s with a turbulent intensity of 0.4%. The wing had an aspect ratio of 1.2 and an angle of attack of 9.7°. The corresponding chord-based Reynolds number was 620,000. The measurements consisted of simultaneously acquired wall-pressure measurements at various streamwise locations and time-resolved particle image velocimetry (PIV) in a streamwise-wall-normal plane. Both measurements showed unsteadiness related to the breathing motion at low Strouhal number Stl ≈ 0.05. Here, Stl is defined based on the characteristic length, l, of the mean turbulent separation bubble (TSB). Cross-correlation between the measured wall pressures at different streamwise locations revealed that the breathing motion propagated at approximately 0.8U downstream of the mean detachment (MD) point. The breathing motion was observed to establish a stronger correlation with the low-frequency wall-pressure fluctuations in the low-intermittency regions as opposed to the high-intermittency regions. Spectral proper orthogonal decomposition was performed using the combined PIV velocity fields and wall-pressure measurements. The results revealed that the expansion (or contraction) of TSB preceded a reduction (or increase) in wall pressure measured upstream of MD and an increase (or reduction) in wall pressure measured downstream of MD. The findings align with the fact that TSB expansion occurs when local adverse pressure gradient (APG) increases, whereas contraction corresponds to a decrease in APG.

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

Access this article

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price includes VAT (Canada)

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

Similar content being viewed by others

Data availability

The data that support the findings of this study are available upon reasonable request from the authors.

References

  • Armstrong EK, Stevenson RE (1960) Some practical aspects of compressor blade vibration. Aeronaut J 64(591):117–130

    Article  Google Scholar 

  • Boiko AV, Dovgal AV, Zanin BY, Kozlov VV (1996) Three-dimensional structure of separated flows on wings. Thermophys Aeromech 3(1):1–13

    Google Scholar 

  • Broeren A, Bragg M (1998) Low-frequency flowfield unsteadiness during airfoil stall and the influence of stall type. In: 16th AIAA Applied Aerodynamics Conference: 2517

  • Broeren A, Bragg M (2001) Spanwise variation in the unsteady stalling flowfields of two-dimensional airfoil models. AIAA J 39(9):1641–1651

    Article  Google Scholar 

  • Brunn A, Nitsche W (2003) Separation control by periodic excitation in a turbulent axisymmetric diffuser flow. J Turbul 4(1):009

    Google Scholar 

  • Camussi R, Felli M, Pereira F, Aloisio G, Di Marco A (2008) Statistical properties of wall pressure fluctuations over a forward-facing step. Phys Fluids 20(7):075113

    Article  Google Scholar 

  • Carusone A, Sicot C, Bonnet JP, Borée J (2021) Transient dynamical effects induced by single-pulse fluidic actuation over an airfoil. Exper Fluid 62:1–16

    Article  Google Scholar 

  • Castro IP (1981) Measurements in shear layers separating from surface-mounted bluff bodies. J Wind Eng Ind Aerodyn 7(3):253–272

    Article  Google Scholar 

  • Castro IP, Haque A (1987) The structure of a turbulent shear layer bounding a separation region. J Fluid Mech 179:439–468

    Article  Google Scholar 

  • Cattafesta LN III, Sheplak M (2011) Actuators for active flow control. Annu Rev Fluid Mech 43:247–272

    Article  Google Scholar 

  • Cherry NJ, Hillier R, Latour MEMP (1984) Unsteady measurements in a separated and reattaching flow. J Fluid Mech 144:13–46

    Article  Google Scholar 

  • D’Adamo J, Sosa R, Artana G (2014) Active control of a backward facing step flow with plasma actuators. J Fluids Eng 136(12):121105

    Article  Google Scholar 

  • Dandois J, Garnier E, Sagaut P (2007) Numerical simulation of active separation control by a synthetic jet. J Fluid Mech 574:25–58

    Article  Google Scholar 

  • Dell’Orso H, Amitay M (2018) Parametric investigation of stall cell formation on a NACA 0015 airfoil. AIAA J 56(8):3216–3228

    Article  Google Scholar 

  • Dell’Orso H, Tuna BA, Amitay M (2016) Measurement of three-dimensional stall cells on a two-dimensional NACA0015 airfoil. AIAA J 54(12):3872–3883

    Article  Google Scholar 

  • Eaton JK, Johnston JP (1982) Low frequency unsteadyness of a reattaching turbulent shear layer. Turbulent shear flows 3. Springer, Berlin, Heidelberg, pp 162–170

    Chapter  Google Scholar 

  • Eaton JK (1980) An evaluation of data for backward facing step flow. In: 1980/81 Conferences on Complex Turbulent Flows. Department of Mechanical Engineering, Stanford University.

  • Farabee TM, Casarella MJ (1986) Measurements of fluctuating wall pressure for separated/reattached boundary layer flows

  • Farren WS (1935) The reaction on a wing whose angle of incidence is changing rapidly. Wind tunnel experiments with a short period recording balance. HM Stationery Office

  • Fiore M, Parisot-Dupuis H, Etchebarne B, Gojon R (2022) Spectral proper orthogonal decomposition of coupled hydrodynamic and acoustic fields: application to im**ing jet configurations (draft). Comput Fluids 241:105484

    Article  MathSciNet  Google Scholar 

  • Garcia-Sagrado A, Hynes T (2011) Wall-pressure sources near an airfoil trailing edge under separated laminar boundary layers. AIAA J 49(9):1841–1856

    Article  Google Scholar 

  • Garcia-Sagrado A, Hynes T (2012) Wall pressure sources near an airfoil trailing edge under turbulent boundary layers. J Fluids Struct 30:3–34

    Article  Google Scholar 

  • Ghaemi S, Ragni D, Scarano F (2012) PIV-based pressure fluctuations in the turbulent boundary layer. Exp Fluids 53(6):1823–1840

    Article  Google Scholar 

  • Gibeau B, Gingras D, Ghaemi S (2020) Evaluation of a full-scale helium-filled soap bubble generator. Exp Fluids 61(2):1–18

    Article  Google Scholar 

  • Gibeau B, Ghaemi S (2021) Low-and mid-frequency wall-pressure sources in a turbulent boundary layer. J Fluid Mech 918

  • Graziani A, Kerhervé F, Martinuzzi RJ, Keirsbulck L (2018) Dynamics of the recirculating areas of a forward-facing step. Exp Fluids 59(10):1–18

    Article  Google Scholar 

  • Greenblatt D, Whalen EA, Wygnanski IJ (2019) Introduction to the flow control virtual collection. AIAA J 57(8):3111–3114

    Article  Google Scholar 

  • Hayes MH (1996) Statistical digital signal processing and modeling. Wiley

    Google Scholar 

  • Hristov G, Ansell PJ (2018) Poststall hysteresis and flowfield unsteadiness on a NACA 0012 airfoil. AIAA J 56(7):2528–2539

    Article  Google Scholar 

  • Hudy LM, Naguib AM, Humphreys WM Jr (2003) Wall-pressure-array measurements beneath a separating/reattaching flow region. Phys Fluids 15(3):706–717

    Article  Google Scholar 

  • Ji M, Wang M (2012) Surface pressure fluctuations on steps immersed in turbulent boundary layers. J Fluid Mech 712:471–504

    Article  MathSciNet  Google Scholar 

  • Kiya M, Sasaki K (1983) Structure of a turbulent separation bubble. J Fluid Mech 137:83–113

    Article  Google Scholar 

  • Le Floc’h A, Weiss J, Mohammed-Taifour A, Dufresne L (2020) Measurements of pressure and velocity fluctuations in a family of turbulent separation bubbles. J Fluid Mech 902:A13

    Article  MathSciNet  Google Scholar 

  • Liu J, **ao Z (2020) Low-frequency oscillation over NACA0015 airfoil near stall at high Reynolds number. AIAA J 58(1):53–60

    Article  MathSciNet  Google Scholar 

  • Ma A, Gibeau B, Ghaemi S (2020) Time-resolved topology of turbulent boundary layer separation over the trailing edge of an airfoil. J Fluid Mech 891:A1

    Article  MathSciNet  Google Scholar 

  • Mabey DG (1992) Review of the normal force fluctuations on aerofoils with separated flow. Prog Aerosp Sci 29(1):43–80

    Article  Google Scholar 

  • Manolesos M, Voutsinas SG (2014b) Study of a stall cell using stereo particle image velocimetry. Phys Fluids 26(4).

  • Manolesos M, Voutsinas SG (2014a) Geometrical characterization of stall cells on rectangular wings. Wind Energy 17(9):1301–1314

    Article  Google Scholar 

  • Mohammed-Taifour A, Weiss J (2016) Unsteadiness in a large turbulent separation bubble. J Fluid Mech 799:383–412

    Article  Google Scholar 

  • Mohammed-Taifour A, Weiss J (2021) Periodic forcing of a large turbulent separation bubble. J Fluid Mech 915:A24

    Article  MathSciNet  Google Scholar 

  • Moss NJ (1979) Measurements of aerofoil unsteady stall properties with acoustic flow control. J Sound Vib 65(4):505–520

    Article  Google Scholar 

  • Na Y, Moin P (1998a) Direct numerical simulation of a separated turbulent boundary layer. J Fluid Mech 374:379–405

    Article  MathSciNet  Google Scholar 

  • Na Y, Moin P (1998b) The structure of wall-pressure fluctuations in turbulent boundary layers with adverse pressure gradient and separation. J Fluid Mech 377:347–373

    Article  MathSciNet  Google Scholar 

  • Nekkanti A, Schmidt OT (2021) Frequency–time analysis, low-rank reconstruction and denoising of turbulent flows using SPOD. J Fluid Mech 926:A26

    Article  Google Scholar 

  • Neunaber I, Danbon F, Soulier A, Voisin D, Guilmineau E, Delpech P, Braud C (2022) Wind tunnel study on natural instability of the normal force on a full-scale wind turbine blade section at Reynolds number 47·106. Wind Energy 25(8):1332–1342

    Article  Google Scholar 

  • Pearson DS, Goulart PJ, Ganapathisubramani B (2013) Turbulent separation upstream of a forward-facing step. J Fluid Mech 724:284–304

    Article  Google Scholar 

  • Piponniau S, Dussauge JP, Debieve JF, Dupont P (2009) A simple model for low-frequency unsteadiness in shock-induced separation. J Fluid Mech 629:87–108

    Article  Google Scholar 

  • Schmidt OT, Colonius T (2020) Guide to spectral proper orthogonal decomposition. AIAA J 58(3):1023–1033

    Article  Google Scholar 

  • Schmidt OT, Towne A, Rigas G, Colonius T, Brès GA (2018) Spectral analysis of jet turbulence. J Fluid Mech 855:953–982

    Article  MathSciNet  Google Scholar 

  • Sigurdson LW (1995) The structure and control of a turbulent reattaching flow. J Fluid Mech 298:139–165

    Article  Google Scholar 

  • Simpson RL (1989) Turbulent boundary-layer separation. Annu Rev Fluid Mech 21(1):205–232

    Article  Google Scholar 

  • Thompson BE, Whitelaw JH (1985) Characteristics of a trailing-edge flow with turbulent boundary-layer separation. J Fluid Mech 157:305–326

    Article  Google Scholar 

  • Towne A, Schmidt OT, Colonius T (2018) Spectral proper orthogonal decomposition and its relationship to dynamic mode decomposition and resolvent analysis. J Fluid Mech 847:821–867

    Article  MathSciNet  Google Scholar 

  • Tsuji Y, Imayama S, Schlatter P, Alfredsson PH, Johansson AV, Marusic I, Monty J (2012) Pressure fluctuation in high-Reynolds-number turbulent boundary layer: results from experiments and DNS. J Turbulence (13): N50

  • Wang S, Ghaemi S (2021) Full-span topology of trailing-edge separation at different angles of attack. AIAA J 59(12):5186–5197

    Article  Google Scholar 

  • Wang S, Ghaemi S (2022) Unsteady motions in the turbulent separation bubble of a two-dimensional wing. J Fluid Mech 948:A3

    Article  MathSciNet  Google Scholar 

  • Weihs D, Katz J (1983) Cellular patterns in poststall flow over unswept wings. AIAA J 21(12):1757–1759

    Article  Google Scholar 

  • Weiss J, Mohammed-Taifour A, Schwaab Q (2015) Unsteady behavior of a pressure-induced turbulent separation bubble. AIAA J 53(9):2634–2645

    Article  Google Scholar 

  • Welch P (1967) The use of fast Fourier transform for the estimation of power spectra: a method based on time averaging over short, modified periodograms. IEEE Trans Audio Electroacoust 15(2):70–73

    Article  Google Scholar 

  • Westerweel J, Scarano F (2005) Universal outlier detection for PIV data. Exp Fluids 39(6):1096–1100

    Article  Google Scholar 

  • Winkelman AE, Barlow JB (1980) Flowfield model for a rectangular planform wing beyond stall. AIAA J 18(8):1006–1008

    Article  Google Scholar 

  • Winkelmann A (1981) An experimental study of separated flow on a finite wing. In: 7th Atmospheric Flight Mechanics Conference, pp. 1882

  • Yon SA, Katz J (1998) Study of the unsteady flow features on a stalled wing. AIAA J 36(3):305–312

    Article  Google Scholar 

  • Zaman KBMQ, Bar-Sever A, Mangalam SM (1987) Effect of acoustic excitation on the flow over a low-Re airfoil. J Fluid Mech 182:127–148

    Article  Google Scholar 

  • Zaman KBMQ, McKinzie DJ, Rumsey CL (1989) A natural low-frequency oscillation of the flow over an airfoil near stalling conditions. J Fluid Mech 202:403–442

    Article  Google Scholar 

Download references

Funding

The project was supported by the Future Energy Systems grant at the University of Alberta.

Author information

Authors and Affiliations

Authors

Contributions

S.W. and S.G. wrote the main manuscript text. S.W. and B.G. analyzed the data and prepared the figures. S.W and B.G. carried out the experiments. S.G. contributed to the acquisition of funding and supervision.

Corresponding author

Correspondence to Sina Ghaemi.

Ethics declarations

Conflict of interest

The authors declare that they have no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wang, S., Gibeau, B. & Ghaemi, S. The interaction between turbulent separation bubble breathing and wall pressure on a 2D wing. Exp Fluids 65, 99 (2024). https://doi.org/10.1007/s00348-024-03835-8

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s00348-024-03835-8

Navigation