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Mechanical forcing of the wake of a flat plate

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Abstract

We report experimental results of the forced wake of a thin symmetric flat plate, placed parallel to an uniform air stream, in the range of thickness-based Reynolds number 50< Re e <200. External wake forcing was introduced by small harmonic oscillations of a moving flap, placed at the trailing-edge of the flat plate. When the flap remains in a fixed horizontal position, the mean velocity profiles obtained by hot wire measurements, for different Reynolds numbers, are self similar. In the presence of harmonic forcing, within a certain range of the forcing frequency, the mean velocity profiles change and coherent structures are formed in the wake. Two independent flow-type resonances were observed: (i) when the inverse of the forcing frequency matches the flight time of the fluid particles along the flap. (ii) when the forcing frequency of the flap equals one half of the vortex shedding frequency of the flat plate and flap system. Implications of the two observed resonances on the wake structure are important. The first resonance (i) is associated to a wide but less intense (energy fluctuations) wake flow and the second resonance (ii) generates a thin but intense resultant wake flow.

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References

  • Bearman PW (1984) Vortex shedding from oscillating bluff bodies. Ann Rev Fluid Mech 16:195

    Article  Google Scholar 

  • Gharib M, Williams-Stuber K (1989) Experiments on the forced wake of an airfoil. J Fluid Mech 208:225

    Google Scholar 

  • Gopalkrishnan R, Triantafyllou MS, Triantafyllou GS, Barret D (1994) Active vorticity control in a shear flow using a flapping foil. J Fluid Mech 274:1

    Google Scholar 

  • Hernández RH, Baudet C (2000) A new perturbation method. Application to the Bénard-von Kármán instability. Europhys Lett 49:329

    Article  Google Scholar 

  • Hernández RH, Baudet C (2001) Ultrasound scattering by forced laminar wakes. In: Maurel A, Petitjeans P (eds) Vortex structure and dynamics. Lecture notes in physics, vol 555. Springer, Berlin Heidelberg New York, 173 pp

  • Hernández RH, Sánchez M (2002) Localized Bénard von Kármán vortex wake packets. Europhys Lett 58:222

    Article  Google Scholar 

  • Hourigan K, Thompson MC, Tan BT (2001) Self-sustained oscillations in flows around long blunt plates. J Fluids Struct 15:387

    Article  Google Scholar 

  • Huerrre P (1990) Local and global instabilities in spatially developing flows. Annu Rev Fluid Mech 22:473

    Article  Google Scholar 

  • Kwon K, Choi H (1996) Control of laminar vortex shedding behind a circular cylinder using splitter plates. Phys Fluids 8:479

    Article  CAS  Google Scholar 

  • Landau LD, Lifshitz EM (1973) Theoretical fluid mechanics. Cambridge University Press, New York

  • Liepmann HW, Brown GL, Nosenchuck DM (1982) Control of laminar-instability waves using a new technique. J Fluid Mech 118:187

    Google Scholar 

  • Nakamura Y, Hirata K (1989) Critical geometry of oscillating bluff bodies. J Fluid Mech 208:375

    Google Scholar 

  • Nakamura Y, Ohya Y, Tsuruta H (1991) Experiments on the vortex shedding from flat plates with square leading and trailing edges. J Fluid Mech 222:437

    Google Scholar 

  • Provansal M, Mathis C, Boyer L (1987) Bénard-von Kármán instability: transient and forced regimes. J Fluid Mech 182:1

    CAS  Google Scholar 

  • Roussopoulos K (1993) Feedback control of vortex shedding at low Reynolds numbers. J Fluid Mech 248:267

    CAS  Google Scholar 

  • Schlichting H (1968) Boundary-layer theory. McGraw-Hill, New York

  • Stokes AN, Welsh MC (1986) Flow resonant sound interaction in a duct containing a plate II: Square leading edge. J Sound Vib 104:55

    Google Scholar 

  • Strykowski PJ, Sreenivasan KR (1990) On the formation and suppression of vortex shedding at low Reynolds numbers. J Fluid Mech 218:71

    Google Scholar 

  • Tokumaru PT, Dimotakis PE (1991) Rotary oscillation control of a cylinder wake. J Fluid Mech 224:77

    Google Scholar 

  • Tokumaru PT, Dimotakis PE (1993) The lift of a cylinder executing rotary motions in a uniform flow. J Fluid Mech 255:1

    CAS  Google Scholar 

  • Triantafyllou MS, Triantafyllou GS, Gopalkrishnan R (1991) Wake mechanics for thrust generation in oscillating foils. Phys Fluids 3:2835

    Article  CAS  Google Scholar 

  • Williamson CHK (1988) The existence of two stages in the transition to three dimensionality of a cylinder wake. Phys Fluids 31:3165

    Article  Google Scholar 

  • Williamson CHK (1989) Oblique and parallel modes of vortex shedding in the wake of circular cylinder at low Reynolds numbers. J Fluid Mech 206:579

    Google Scholar 

  • Wygnanski I, Champagne F, Marasli B (1986) On the large-scale structures in two dimensional small-deficit, turbulent wakes. J Fluid Mech 168:31

    Google Scholar 

  • Yamagishi M, Tashiro S (2002) Effect of external fluctuation frequency introduced in the mean-flow on the characteristic frequency of separated flow. JSME Int J Series B 45:796

    Google Scholar 

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Acknowledgements

Grants Fondecyt No 3010067 and Fondecyt No 1020134 are gratefully acknowledged.

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Authors and Affiliations

  1. LEAF-NL, Departamento de Ingeniería Mecánica, Universidad de Chile, Casilla 2777, Santiago, Chile

    M. Vial, L. Bellon & R. H. Hernández

  2. Laboratoire de Physique, Ecole Normale Supérieure de Lyon, 46 Allée d’Italie, 69364, Lyon cedex 07, France

    L. Bellon

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  1. M. Vial
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  2. L. Bellon
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  3. R. H. Hernández
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Correspondence to R. H. Hernández.

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Vial, M., Bellon, L. & Hernández, R.H. Mechanical forcing of the wake of a flat plate. Exp Fluids 37, 168–176 (2004). https://doi.org/10.1007/s00348-004-0796-0

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