KnE Engineering

ISSN: 2518-6841

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Effect of Reynolds Number on a Plunging Airfoil

Published date: Jun 02 2020

Journal Title: KnE Engineering

Issue title: International Congress on Engineering — Engineering for Evolution

Pages: 692–703

DOI: 10.18502/keg.v5i6.7090

Authors:

Diana Carvalho Rodrigues - a33541@ubi.pt

Emanuel António Rodrigues Camacho

Fernando Manuel da Silva Pereira Neves

André Resende Rodrigues Silva

Jorge Manuel Martins Barata

Abstract:

Biomimetics is an area of science that studies the development of new technologies, whose source of inspiration is Nature. Unlike traditional aircraft, animals only have one structure to create both lift and thrust, and for Humans, although in the recent years the studies in this area increased, a long way must be made to achieve their capability. The present paper focuses on the effect of the Reynolds number on the wake configuration produced by a plunging airfoil. The experimental work was performed using an airstream, that was marked with smoke, with an oscillating airfoil NACA0012, whose dimensions are 44cm and 10cm of span and aerodynamic chord, respectively. The motion prescribed for the wing is harmonic, since it very well represents the type of motion seen in Nature. Frequency and amplitude were maintained, respectively, at 1.2Hz and 2.8cm, and the wind speed range from 0.25m/s to 1.00m/s, which represents a nondimensional amplitude of 0.28, a reduced frequencies of 3.02, 1.51 and 0.75, and a Strouhal number and a Reynolds number range of, 0.07 – 0.27 and 1,500 – 6,300, respectively. Results indicate that, with the increase of the Reynolds number, the convection effects become more predominant than diffusion effects, the curvature of the wakes and the maximum effective angle of attack decrease, and time and configuration of vortex shedding change. For Re = 1,500, St = 0.27, another relevant conclusion appears; the interaction of the leading-edge vortex with the trailing-edge vortex indicates an improvement of the aerodynamic performance of this system.

Keywords: Biomimetics, Plunging, Airfoil, Vortices, Wakes

References:

[1] Lee J.-S.; Kim, C.; Kim, K.H., ”Design of Flapping Airfoil for Optimal Aerodynamic Performance in Low- Reynolds,” AIAA Journal, vol. 44, p. 1960–1972, 2006.

[2] Barata, J. M. M.; Manquinho, P. A. R.; Neves, F. M. S. P.; Silva, T. J. A., ”Propulsion for Biological Inspired Micro-Air Vehicles (MAVs)”, ICEUBI, International Conference on Engineering, Engineering for Society, Covilhã, 02/04 December 2015.

[3] Barata, J. M. M.; Manquinho, P. A. R.; Neves, F. M. S. P.; Silva, T. J. A., ”Propulsion for Biological Inspired Micro-Air Vehicles (MAVs),” Open Journal of Applied Sciences, vol. 66, no. 1, pp. 7-15, 2016.

[4] Barata, J. M. M.; Manquinho, P. A. R., Neves, F. M. S. P.; ”Comparative Study of Wing’s Motion Patterns on Various Types of Insects on Resemblant Flight Stages,” AIAA Science and Technology Forum 2015, Kissimmee, Florida, USA, 05/09 January 2015.

[5] Barata, J. M. M.; Silva, T. J. A.; Neves, F. M. S. P.; Silva, A. R. R, ”Experimental Analysis of Forces During Take-Off of Birds,” AIAA Science and Technology Forum and Exposition 2017, 09/13 January 2017, Grapevine, Texas, USA.

[6] Barata, J. M. M.; Neves, F. M. S. P.; Manquinho, P. A. R.; Silva, A. R. R, ”Biological Inspired Propulsion of Micro-Air Vehicles,” 7th ECCOMAS, SMART 2015, Ponta Delgada, S. Miguel, Azores, Portugal, 3 - 6 June 2015.

[7] McMichael, J. M.; Francis, M. S., ”Micro Air Vehicles - Toward a New Dimension in Flight”, http://www. fas.org/irp/program/collect/docs/mav_auvsi.htm (28.09.2019).

[8] Petricca, L.; Ohlckers, P.; Grinde, C., ”Micro- and Nano-Air Vehicles: State of the Art”, International Journal of Aerospace Engineering, Vol. 2011, Article ID 214549, 17 pages.

[9] Hylton, T.; Martin, C.; Tun, R.; Castelli, V., ”The DARPA Nano Air Vehicle Program,” 50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, 09-12 January 2012, Nashville, Tennessee, USA.

[10] Knoller, R., ”Die Gesetze des Luftwiderstandes,” Flug- und Motortechnik (Wien), vol. 3, no. 21, pp. 1–7, 1909.

[11] Betz, A., ”Ein Beitrag zur Erklaerung des Segelfluges,” Zeitschrift fur Flugtechnik und Motorluftschiffahrt, Vol. 3, pp. 269–272, 1912.

[12] Lai, J.C.S.; Platzer, M. F., ”Jet characteristics of a plunging airfoil,” AIAA Journal, vol. 37, no. 12, pp. 1529–1537, 1999. 6, 16, 19

[13] Lewin, G. C.; Haj-Hariri, H., ”Modelling thrust generation of a two-dimensional heaving airfoil in a viscous flow, ” Journal of Fluid Mechanics, vol. 492, p. 339–362, 2003. 6

[14] Young, J., ”Numerical simulation of the unsteady aerodynamics of flapping airfoils,” Ph.D. dissertation, The University of New South Wales, Australian Defence Force Academy, 2005.

[15] J. Young, J.; Lai, J. C. S., ”Vortex lock-in phenomenon in the wake of a plunging airfoil,” AIAA Journal, vol. 45, no. 2, pp. 485–490, 2007. 6, 10, 23

[16] Taylor, R. L. N. G. K.; Thomas, A. L. R., ”Flying and swimming animals cruise at a Strouhal number tuned for high power efficiency,” Nature (London), vol. 425, pp. 707–711, 2003. 7

[17] Camacho, E. A. R., ”Numerical Analysis of a Plunging NACA0012 Airfoil,” Master’s Dissertation, Universidade da Beira Interior, Covilhã, Portugal, 2019.

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