Advertisement

DNS of Separated Low-Re Flow Around a Cambered Aerofoil

  • M. F. ShahabEmail author
  • M. Omidyeganeh
  • A. Pinelli
Conference paper
Part of the ERCOFTAC Series book series (ERCO, volume 25)

Abstract

Recent improvements in manufacturing and control technology have led to the introduction of a new class of micro and even nano sized air vehicles (Micro/Nano UAVs) operating in flight conditions characterized by a medium-to-low Reynolds number and by background flow unsteadiness that may lead to critical aerodynamic conditions such as massive separation, dynamic stall and aerodynamic hysteresis. Although the effect of low Reynolds number regimes and its impact on boundary layer separation and flow unsteadiness have been the subject of many previous studies, fully stalled conditions did not receive much attention in the past. Using Direct Numerical Simulation, the present contribution addresses the spatio-temporal characterisation of the flow around a cambered aerofoil in deeply stalled conditions. A joint analysis of the flow structure and of the velocity time signal sampled in different locations allows to highlight the presence of a number of unsteady features that govern the overall behaviour of the flow field.

Notes

Acknowledgements

The authors gratefully acknowledge the support of the Engineering and Physical Sciences Research Council under the project Quiet Aerofoils of the Next Generation (EP/N020413/1) and ARCHER, the UK high-performance computing facility.

References

  1. 1.
    Gaster, M.: The structure and behaviour of laminar separation bubbles, Aerodynamics Division N.P.L., Report and Memoranda No. 3595 (1967)Google Scholar
  2. 2.
    Hain, R., Kahler, C.J., Radespiel, R.: Dynamics of laminar separation bubbles at low-Reynolds-number airfoils. J. Fluid Mech. 630, 129–153 (2009)CrossRefGoogle Scholar
  3. 3.
    Huang, R.F., Lin, C.L.: Vortex shedding and shear-layer instability of wing at low-Reynolds numbers. AIAA J. 33(8), 1398–403 (1995)CrossRefGoogle Scholar
  4. 4.
    Jones, L.E., Sandberg, R.D.: Acoustic and hydrodynamic analysis of the flow around an aerofoil with trailing-edge serrations. J. Fluid Mech. 706, 295–322 (2012)CrossRefGoogle Scholar
  5. 5.
    Liu, X., Jawahar, J.K., Azarpeyvand, M., Theunissen, R.: Aerodynamic and aeroacoustic performance of serrated airfoils. In: 21st AIAA/CEAS Aeroacoustics Conference, AIAA AVIATION Forum. Dallas, Tx (2015)Google Scholar
  6. 6.
    Rosti, M.E., Omidyeganeh, M., Pinelli, A.: Direct numerical simulation of the flow around an aerofoil in ramp-up motion. Phys. Fluids 28, 025106 (2016)CrossRefGoogle Scholar
  7. 7.
    Yarusevych, S., Sullivan, P.E., Kawall, J.G.: On vortex shedding from an airfoil in low-Reynolds-number flows. J. Fluid Mech. 632, 245–271 (2009)CrossRefGoogle Scholar
  8. 8.
    Yarusevych, S., Boutilier, M.S.H.: Vortex shedding of an airfoil at low Reynolds numbers. AIAA J. 49(10), 2221–27 (2011)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.City, University of LondonLondonUK

Personalised recommendations