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Spatial evolution of wall-imposed disturbance in pipe flow

Spatial evolution of wall-imposed disturbance in pipe flow. Cas van Doorne, 1 Jerry Westerweel, 1 Frans Nieuwstadt ( †) , Tobias Schneider 2 & Bruno Eckhardt 2 1 Laboratory for Aero & Hydrodynamics, Delft University of Technology The Netherlands

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Spatial evolution of wall-imposed disturbance in pipe flow

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  1. Spatial evolution of wall-imposed disturbance in pipe flow Cas van Doorne,1 Jerry Westerweel,1 Frans Nieuwstadt (†), Tobias Schneider2 & Bruno Eckhardt2 1Laboratory for Aero & Hydrodynamics, Delft University of Technology The Netherlands 2Fachbereich Physik, University of Marburg, Germany

  2. Motivation • Transition in pipe flow has remained an unresolved problem (Reynolds 1883) • Experimental validation of the transition scenario (e.g., DNS by Ma Bing et al. 1999) • What is the nature of the boundary between laminar and turbulent flow? (Edge of Chaos, Skufka et al. 2006) • Turbulence control?

  3. Laminar disturbance mechanism

  4. Stereo PIV: optical configuration

  5. Stereo PIV

  6. The edge of chaos

  7. Numerical edge trajectory Skufka, Yorke, Eckhardt, PRL 96 (2006) 174101

  8. Edge state structure: off-center jet Experiment Numerical simulation Re = 3000 Re = 2875

  9. LIF visualization

  10. z / D = 3.0

  11. z / D = 5.0

  12. z / D = 8.1

  13. z / D = 11.3

  14. z / D = 14.4

  15. Fully developed turbulence

  16. Reconstructed vorticity

  17. Spectral mode decomposition Re = 3000, 0.25 Hz DNS S-PIV

  18. Conclusions • Flow transition induced by laminar disturbance mechanism • High-precision S-PIV set-up for measuring cross-flow • Disturbance mimics the edge of chaos flow structure • Quantitative measurement of development of streaks into packets of hairpin vortices • Next:add second disturbance mechanism to achieve flow control in experimental configuration

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