Abstract
The idea of using sinusoidal leading edge as a kind of passive flow control method was inspired by observing the flipper movement of the humpback whale. It was believed that the protuberances along the whale’s pectoral fin could delay stall, thus would enhance the maneuverability of the whale. It has also been shown that when equipped with sinusoidal leading edges, the stall of a delta wing could be delayed. In this paper, stereoscopic particle image velocimetry was adopted to study the vortex structures for the flow over a 52° swept delta wing with sinusoidal leading edges. A direct comparison with the flow over a baseline delta wing was made to illustrate the different vortex structures of these two kinds of models. Results have shown that the flow over the baseline delta wing was dominated by dual leading-edge vortices (LEVs), a structure that only existed for flow over nonslender delta wing at certain Reynolds number. On the other hand, the flow over the one with sinusoidal leading edge showed a very different pattern. It has been found in this paper that there were several pairs of LEVs existed on the leeward side of the wing, which might explain the stall-delaying effect of the delta wing with sinusoidal leading edges.
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References
Adrian RJ, Christensen KT, Liu Z (2000) Analysis and interpretation of instantaneous turbulent velocity fields. Exp Fluids 29(3):275–290
Chen L, Wang JJ, Zuo LX et al (2010) Influence of Reynolds number on vortex flow over a non-slender delta wing. AIAA J 48(12):2831–2839
Chen H, Pan C, Wang JJ (2013) Effects of sinusoidal leading edge on delta wing performance and mechanism. Sci China Technol Sci 56(3):772–779
Delery JM (1994) Aspects of vortex breakdown. Prog Aerosp Sci 30:1–59
Edel RK, Winn HE (1978) Observations on underwater locomotion and flipper movement of the humpback whale Megaptera novaeangliae. Mar Biol 48:279–287
Fish FE, Battle JM (1995) Hydrodynamic design of the humpback whale flipper. J Morphol 255:51–60
Fish FE, Webber PW, Murray MM et al (2011a) The humpback whale’s flipper: application of bio-inspired tubercle technology. Integr Comp Biol 51:203–213
Fish FE, Webber PW, Murray MM et al (2011b) Marine applications of the biomimetic Humpback whale flipper. Mar Technol Soc J 45(4):198–207
Goruney T, Rockwell D (2009) Flow past a delta wing with a sinusoidal leading edge: near-surface topology and flow structure. Exp Fluids 57:321–331
Guerreiro JLE, Sousa JMM (2012) Low-Reynolds-number effects in passive stall control using sinusoidal leading edges. AIAA J 50(2):461–469
Gursul I, Taylor G, Wooding C (2002) Vortex flow over fixed-wing micro air vehicles. Paper presented at the 40th AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada
Gursul I, Wang Z, Vardaki E (2007) Review of flow control mechanisms of leading-edge vortices. Prog Aerosp Sci 43:246–270
Hansen KL, Kelso RM, Dally BB (2011) Performance variations of leading-edge tubercles for distinct airfoil profiles. AIAA J 49(1):185–194
Johari H, Henoch C, Custodio D et al (2007) Effects of leading-edge protuberances on airfoil performance. AIAA J 45:2634–2642
Lee M, Ho CM (1990) Lift force of delta wings. Appl Mech Rev 43(9):209–221
Miklosovic DS, Murray MM, Howle LE et al (2004) Leading-edge tubercles delay stall on humpback whale (Megaptera novaeangliae) flippers. Phys Fluids 16(5):L39–L42
Miklosovic DS, Murray MM, Howle LE (2007) Experimental evaluation of sinusoidal leading edges. J Aircr 44(4):1404–1408
Ol MV, Gharib M (2003) Leading-edge vortex structure of nonslender delta wings at low Reynolds number. AIAA J 41(1):16–26
Raffel M, Willert CE, Wereley ST et al (2007) Particle image velocimetry-a practical guide, 2nd edn. Springer, Heidelberg
Rockwell D (1993) Three-dimensional flow structure on delta wings at high angle-of-attack: experimental concepts and issues. Paper presented at the 31st AIAA aerospace sciences meeting and exhibit, Reno, Nevada
Scheimpflug T (1904) Improved method and apparatus for the systematic alteration or distortion of plane pictures and images by means of lenses and mirrors for photography and for other purposes. British Patent
Taylor GS, Schnorbus T, Gursul I (2003) An investigation of vortex flows over low sweep delta wing. Paper presented at the 33rd AIAA fluid dynamics conference and exhibit, Orlando, Florida
Wang JJ, Zhang W (2008) Experimental investigations on leading-edge vortex structures for flow over non-slender delta wings. Chinese Phys Lett 25(7):2550–2553
Watts P, Fish FE (2001) The influence of passive, leading edge tubercles on wing performance. In: Proceedings of the unmanned untethered submersible technology (UUST01), New Hampshire, 2001. Autonomous Undersea Systems Institute
Zhou J, Adrian RJ, Balachandar S et al (1999) Mechanisms for generating coherent packets of hairpin vortices in channel flow. J Fluid Mech 287:353–396
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Chen, H., Wang, JJ. Vortex structures for flow over a delta wing with sinusoidal leading edge. Exp Fluids 55, 1761 (2014). https://doi.org/10.1007/s00348-014-1761-1
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DOI: https://doi.org/10.1007/s00348-014-1761-1