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

  • Shailesh Kr Jha
  • Uddipta Gautam
  • Pramod Pawar
  • S. NarayananEmail author
  • L. A. Kumaraswamidhas
Research Paper
  • 42 Downloads

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.

Keywords

NACA0012 airfoil Flat plate Sharp trailing edge Lift/drag coefficients 

List of Symbols

c

Chord length of the foil (m)

cd

Coefficient of drag

cl

Coefficient of lift

cp

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) (°)

Notes

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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Copyright information

© Shiraz University 2019

Authors and Affiliations

  • Shailesh Kr Jha
    • 1
  • Uddipta Gautam
    • 1
  • Pramod Pawar
    • 1
  • S. Narayanan
    • 1
    Email author
  • L. A. Kumaraswamidhas
    • 1
    • 2
  1. 1.Department of Mechanical EngineeringIndian Institute of Technology (ISM)DhanbadIndia
  2. 2.Department of Mining Machinery EngineeringIndian Institute of Technology (ISM)DhanbadIndia

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