Unsteady aerodynamics over NACA0005 airfoil for ultra-low Reynolds numbers

Date

2024-01-01

Author

Kouser, Taiba
Kurtuluş, Dilek Funda
Aliyu, Abdulrahman
Goli, Srikanth
Alhems, Luai M.
IMRAN, Imil Hamda
Memon, Azhar

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

28
views

11
downloads

Cite This

Numerical simulation for a two-dimensional NACA0005 is performed for angle of attack α = 0° − 15° in present study. The Reynolds numbers 1000, 2000 and 5000 are considered. Simulations show that the flow fields can be classified due to characteristics of vortex shedding based on Reynolds number and angle of attack. Furthermore, this study reveals that in case of the thinner airfoils, several modes (Mode I, Mode II, Mode III) are present at same angle of attack for varying Reynolds number. Maximum lift to drag ratio is found at Reynolds number 5000 and angle of attack 6° as well as gradual stall is observed. Onset of oscillations to determine critical angles of attack are reported for NACA0005 with the dominant frequencies. A subcategory of mode III termed as mode IIIa/c, and recently reported mode 4i is also observed in present study. A new mode termed as k-mode is observed for higher angles of attack at Re = 5000. In addition, numerical simulations of two-dimensional periodic flows around NACA0005 profile at Reynolds number Re = 5000 demonstrate that unsteady periodic flows reach different saturation states at angles of attack of 10° − 15°. The coexisting periodic states and period-doubling (with higher and lower intensities) in this range, indicate that the wake undergoes substantial changes from the von-Kármán vortex street.

Subject Keywords

Airfoil, critical angle, flow modes, k-mode, low reynolds number, NACA0005

URI

https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85196121659&origin=inward
https://hdl.handle.net/11511/110234

Collections

Department of Aerospace Engineering, Article