Large-eddy simulations (LES) over a NACA0018 airfoil at a low Reynolds number (Re = 50, 000) fluid flow are performed to investigate the effect of active flow control at different angles of attack (AOA = 10 to 20 degrees) using low amplitude surface morphing backward (opposite to the airfoil’s forward motion) traveling wave actuation on the suction (upper) side of the airfoil. The curvilinear immersed boundary (CURVIB) method is used to handle the moving surface of the airfoil. While our previous simulations indicated the effectiveness of traveling waves at near stall angle of attack (AOA = 15 degrees), the effectiveness of these waves at post-stall AOA such as AOA = 20 degrees is not understood. The actuation amplitude of the surface morphing traveling waves is a* = 0.001 (a* = a/L, a: amplitude, L: chord length of the airfoil), and the range of the reduced frequency (f* = fL/U, f: frequency, U: free stream velocity) is from f* = 4 to 16. The results of the simulations at the post-stall angle of attack (AOA = 20 degrees) show that the lift coefficient, CL, increases by about 23%, and the drag coefficient, CD, decreases by about 54% within the frequency range from f* = 8 to f* = 10.
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Effect of Reynolds Number on Traveling Wave Flow Control
Large-eddy simulations (LES) of the fluid flow over a NACA0018 airfoil at AOA =20 degrees angle of attack are performed to investigate the effect of surface morphing oscillations on the aerodynamic performance of the airfoil over a wide range of Reynolds numbers (Re = 5,000 to 500,000). These oscillations are in the form of low amplitude backward (opposite to the airfoil's forward motion) traveling wave actuations on the upper surface of the airfoil. The sharp interface curvilinear immersed boundary (CURVIB) method is used to handle the moving surface of the airfoil. The nondimensional amplitude is a*=0.001 (a*=a/L; a: amplitude, L: chord length of the airfoil) and reduced frequency (f*= fL/U; f is the frequency and U is the freestream velocity) is chosen to match the leading edge vortex shedding frequency. The results of the simulations at the post-stall angle of attack (AOA =20 degrees) show that the lift coefficient increases more than 20% and the drag coefficient decreases more than 40% within the Reynolds number range of Re = 50,000-500,000 for traveling wave actuation of amplitude, a*=0.001, and frequency, f*=8. However, the lift and drag coefficients of the actuated airfoil were similar to the baseline airfoil for Re = 5,000.
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- Award ID(s):
- 1905355
- NSF-PAR ID:
- 10483399
- Publisher / Repository:
- American Institute of Aeronautics and Astronautics
- Date Published:
- Journal Name:
- AIAA SCITECH 2023 Forum
- Page Range / eLocation ID:
- AIAA 2023-2137
- Format(s):
- Medium: X
- Location:
- National Harbor, MD & Online
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.2514/6.2023-2137
