Investigations of Flow Phenomena Over a Flat Plate and NACA0012 Airfoil at High Angles of Attack

Abstract

In the present study, the flow and aerodynamic features of a sharp trailing edged flat plate airfoil are systematically compared with NACA0012 airfoil. The studies are conducted for three different Reynolds numbers 1.89 × 105, 2.83 × 105 and 3.78 × 105 and angles of attack 20°, 25° and 30°. The present study shows that the occurrence of vortex shedding phenomena for the flat plate is substantially different from NACA0012 airfoil. Further, the re-attachment location of the shed vortices is closer to the trailing edge for the flat plate, whereas for NACA0012 airfoil it occurs at a certain distance upstream of the trailing edge. The NACA0012 airfoil generates higher lift coefficients at a higher Reynolds numbers of 2.83 × 105 and 3.78 × 105, whereas for the flat plate it occurs at a lower Reynolds number of 1.89 × 105. The spectra of lift coefficient reveal that the amplitude of the primary shedding frequency dominates for the flat plate and NACA0012 airfoil at lower and higher Reynolds numbers of 1.89 × 105 and 3.78 × 105, respectively, while it becomes almost same for an intermediate Reynolds number of 2.83 × 105. The present study reveals that the drag coefficient at high Reynolds number (3.78 × 105) is directly proportional to the initial merging point of the two shed vortices for both the flat plate and NACA0012 airfoil.

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Abbreviations

c :

Chord length of the foil (m)

c d :

Coefficient of drag

c l :

Coefficient of lift

c p :

Coefficient of pressure

f :

Frequency (Hz)

p :

Pressure (Pascal)

Re :

Reynolds number (ρUc/µ)

St :

Strouhal number (fc/U)

U :

Free stream velocity (m/s)

α :

Angle of attack (AOA) (°)

References

  1. Chen JM, Fang Y-C (1996) Strouhal numbers of inclined flat plates. J Wind Eng Ind Aerodyn 61(2-3):99–112

    Article  Google Scholar 

  2. Cleaver DJ, Wang Z, Gursul I (2013) Investigation of high-lift mechanisms for a flat-plate airfoil undergoing small-amplitude plunging oscillations. AIAA J 51(4):968–980

    Article  Google Scholar 

  3. Fage A, Johansen FC (1927) On the flow of air behind an inclined flat plate of infinite span. Proc R Soc Lond Ser A Contain Pap Math Phys Character 116(773):170–197

    MATH  Google Scholar 

  4. Jha SK, Narayanan S, Kumaraswamidhas LA (2019) Investigations of flow phenomena behind a flat plate with circular trailing edge. J Braz Soc Mech Sci Eng 41(5):227

    Article  Google Scholar 

  5. Johnson JP, Iaccarino G, Chen K-H, Khalighi B (2014) Simulations of high Reynolds number air flow over the NACA-0012 airfoil using the immersed boundary method. J Fluids Eng 136(4):040901

    Article  Google Scholar 

  6. Kunihiko T, Colonius T (2009) Effect of tip vortices in low-Reynolds-number poststall flow control. AIAA J 47(3):749–756

    Article  Google Scholar 

  7. Lam KM, Leung MYH (2005) Asymmetric vortex shedding flow past an inclined flat plate at high incidence. Eur J Mech B Fluids 24(1):33–48

    Article  Google Scholar 

  8. Lam KM, Wei CT (2010) Numerical simulation of vortex shedding from an inclined flat plate. Eng Appl Comput Fluid Mech 4(4):569–579

    Google Scholar 

  9. Lee H, Kang S-H (2000) Flow characteristics of transitional boundary layers on an airfoil in wakes. J Fluids Eng 122(3):522–532

    Article  Google Scholar 

  10. Lin YF, Lam K, Zou L, Liu Y (2013) Numerical study of flows past airfoils with wavy surfaces. J Fluids Struct 36:136–148

    Article  Google Scholar 

  11. Mizoguchi M, Itoh H (2013) Effect of facet ratio on aerodynamic characteristics at low Reynolds numbers. AIAA J 51(7):1631–1639

    Article  Google Scholar 

  12. Moffat RJ (1988) Describing the uncertainties in experimental results. Exp Therm Fluid Sci 1(1):3–17

    Article  Google Scholar 

  13. Narasimhamurthy VD, Andersson HI (2009) Numerical simulation of the turbulent wake behind a normal flat plate. Int J Heat Fluid Flow 30(6):1037–1043

    Article  Google Scholar 

  14. Shehata H et al (2018) Aerodynamic analysis of flapped airfoil at high angles of attack. 2018 AIAA aerospace sciences meeting

  15. Shehata H et al (2019) Aerodynamic response of a NACA-0012 airfoil undergoing non-sinusoidal pitching waveforms. AIAA Scitech 2019 forum

  16. Yang D et al (2012) Three-dimensional wake transition behind an inclined flat plate a. Phys Fluids 24(9):094107

    Article  Google Scholar 

  17. Zakaria MY, Taha HE, Hajj MR (2017) Measurement and modeling of lift enhancement on plunging airfoils: a frequency response approach. J Fluids Struct 69:187–208

    Article  Google Scholar 

  18. Zakaria MY et al (2018) A computational study of vortex shedding from a NACA-0012 airfoil at high angles of attack. Int J Aerodyn 6(1):1–17

    Article  Google Scholar 

Download references

Acknowledgements

The authors gratefully acknowledge that the current work (ECR/2016/000640) has been supported by DST (Science and Engineering Research Board (SERB)).

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Correspondence to S. Narayanan.

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Jha, S.K., Gautam, U., Pawar, P. et al. Investigations of Flow Phenomena Over a Flat Plate and NACA0012 Airfoil at High Angles of Attack. Iran J Sci Technol Trans Mech Eng 44, 985–996 (2020). https://doi.org/10.1007/s40997-019-00313-z

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Keywords

  • NACA0012 airfoil
  • Flat plate
  • Sharp trailing edge
  • Lift/drag coefficients