Effect of Leading Edge Protuberance on Thrust Production of a Dynamically Pitching Aerofoil

• Published in: Topical Problems of Fluid Mechanics 2017
• Main Authors: Benaissa, M., Ibrahim, I.H., New, T.H., Ho, W.H.
• Other Authors: Šimurda, David, Bodnár, Tomáš
• Format: Conference Object
• Language: English
• Published: 2017
• Subjects: Humpback Whale
• Online Access: http://eprints.gla.ac.uk/152282/; http://eprints.gla.ac.uk/152282/1/152282.pdf

The paper presents a computational analysis of the characteristics of a NACA 634-021 aerofoil modified by incorporating sinusoidal leading-edge protuberances at Re = 14,000. The protuberances are from the tubercles of the humpback whale flipper with leading edge acting as passive-flow control devices that improve performance and manoeuvrability of the flipper. They are characterized by an amplitude and wavelength of 12% and 50% of the aerofoil chord length respectively. Three-dimensional CFD on the modified aerofoil oscillating about a point located on the centreline at quarter-chord has been performed with the frequency and amplitude of oscillation being 4Hz and 10 deg respectively. In addition to the lift and thrust coefficients, near wall flow visualisations and the shedding of vortices during oscillations are presented to illustrate the unsteady flow features on the performance of the oscillating flipper. The results show an improvement in the thrust production when compared to previous studies on similar symmetric aerofoil without the leading edge modifications.