Statistical model and universality class for interacting puffs in transitional turbulence

ORAL

Abstract

To understand the universality class of the laminar-turbulent transition in pipe flow, we measure how turbulent regions known as puffs proliferate and interact. Because of the huge length and time scales required to reach the critical regime, we model the dynamics from the effective forces we measure in experiments. Away from the transition, we find a crystal-like pattern with spatio-temporal intermittency. Renormalization group analysis and numerical simulations of both discrete and continuous models of puff interactions show that interactions are irrelevant at the 1+1-dimensional directed percolation fixed point but several finite-size artifacts mask the critical scaling regime in practice.

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Presenters

  • Hong-Yan Shih

    • Institute of Physics, Academia Sinica and Department of Physics, University of Illinois at Urbana-Champaign

Authors

  • Grégoire Lemoult

    • Normandie Université and Institute of Science and Technology Austria

  • Mukund Vasudevan

    • Institute of Science and Technology Austria

  • Jose M Lopez

    • Institute of Science and Technology Austria

  • Hong-Yan Shih

    • Institute of Physics, Academia Sinica and Department of Physics, University of Illinois at Urbana-Champaign

  • Gaute Linga

    • The Njord Center, University of Oslo and Niels Bohr Institute, University of Copenhagen

  • Bjoern Hof

    • Institute of Science and Technology Austria
    • Physics, IST Austria

  • Joachim Mathiesen

    • Niels Bohr Institute, University of Copenhagen

  • Nigel Goldenfeld

    • University of Illinois at Urbana-Champaign
    • Department of Physics, University of Illinois at Urbana-Champaign
    • Physics, University of Illinois at Urbana-Champaign

  • Bjoern Hof

    • Institute of Science and Technology Austria
    • Physics, IST Austria