Experiments in Fluids

, 57:40 | Cite as

Closed-loop separation control over a sharp edge ramp using genetic programming

  • Antoine DebienEmail author
  • Kai A. F. F. von Krbek
  • Nicolas Mazellier
  • Thomas Duriez
  • Laurent Cordier
  • Bernd R. Noack
  • Markus W. Abel
  • Azeddine Kourta
Research Article


We experimentally perform open and closed-loop control of a separating turbulent boundary layer downstream from a sharp edge ramp. The turbulent boundary layer just above the separation point has a Reynolds number \(Re_{\theta }\approx 3500\) based on momentum thickness. The goal of the control is to mitigate separation and early re-attachment. The forcing employs a spanwise array of active vortex generators. The flow state is monitored with skin-friction sensors downstream of the actuators. The feedback control law is obtained using model-free genetic programming control (GPC) (Gautier et al. in J Fluid Mech 770:442–457, 2015). The resulting flow is assessed using the momentum coefficient, pressure distribution and skin friction over the ramp and stereo PIV. The PIV yields vector field statistics, e.g. shear layer growth, the back-flow area and vortex region. GPC is benchmarked against the best periodic forcing. While open-loop control achieves separation reduction by locking-on the shedding mode, GPC gives rise to similar benefits by accelerating the shear layer growth. Moreover, GPC uses less actuation energy.


Feedback flow control Turbulent boundary layer Active vortex generators Machine learning control Genetic programming 



This work was supported by French National Research Agency (ANR) via the SepaCoDe Project (ANR-11-BS09-018) and the TUCOROM Chair of Excellence (ANR-10-CEXC-0015).


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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Antoine Debien
    • 1
    Email author
  • Kai A. F. F. von Krbek
    • 2
  • Nicolas Mazellier
    • 1
  • Thomas Duriez
    • 3
  • Laurent Cordier
    • 2
  • Bernd R. Noack
    • 4
    • 5
  • Markus W. Abel
    • 6
  • Azeddine Kourta
    • 1
  1. 1.Université d’Orléans, INSA-CVL, PRISME EA 4229OrléansFrance
  2. 2.Institute PPRIME, CNRS - Université de Poitiers - ENSMA, UPR 3346, Département Fluides, Thermique, Combustion, CEATPoitiers CedexFrance
  3. 3.CONICET, Universidad de Buenos AiresCiudad Autonoma de Buenos AiresArgentina
  4. 4.LIMSI, CNRSCampus Universitaire d′OrsayOrsay CedexFrance
  5. 5.Institut für Strömungsmechanik, Technische Universität BraunschweigBraunschweigGermany
  6. 6.Ambrosys GmbHPotsdamGermany

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