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Control of Near-wall Turbulence by Stabilizing Saddle-type Steady Flow

Research Project

Project/Area Number 13650183
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Fluid engineering
Research InstitutionKyoto University

Principal Investigator

KAWAHARA Genta  Kyoto University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (50214672)

Co-Investigator(Kenkyū-buntansha) NAGATA Masato  Kyoto University, Graduate School of Engineering, Professor, 工学研究科, 教授 (80303858)
ITANO Tomoaki  Kyoto University, Graduate School of Engineering, Research Associate, 工学研究科, 助手 (30335187)
Project Period (FY) 2001 – 2003
Project Status Completed (Fiscal Year 2003)
Budget Amount *help
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2002: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 2001: ¥2,400,000 (Direct Cost: ¥2,400,000)
KeywordsTurbulent Flow / Wall Turbulence / Saddle-type Steady Flow / Saddle-type Periodic Flow / Streamwise Vortex / Streak / Burst / Controlling Chaos / サドル状時間周期流縦渦 / 渦構造 / 流れ不安定性 / 波状渦面 / 壁面乱流 / 乱流制御 / 再生・維持サイクル
Research Abstract

In this project we first searched for saddle-type steady flows in a plane Couette system. We obtained quiescent states of the saddle type which appeared transiently in direct numerical simulations of turbulent flow, and then the quiescent states were used as an initial guess for the Newton iteration to numerically compute three-dimensional saddle solutions to the incompressible Navier-Stokes equation. At the lowest Reynolds number for self-sustaining turbulence we have also succeeded in numerically obtaining unstable periodic motion embedded in the Couette turbulence by using the original iterative method with the aid of the direct numerical simulations. This periodic saddle is a three-dimensional periodic solution, and it represents well the regeneration cycle of near-wall coherent structures, i.e., streaks and streamwise vortices. In order to demonstrate similarities of the saddle solutions obtained in the Couette system with those in a plane Poiseuille system we next compared their … More properties with those in a fully turbulent state of these systems. It has been found in the comparison that the mean velocity and the RMS velocities in the buffer region of near-wall turbulence are in excellent agreement with the corresponding velocities of the saddle solutions.
On the other hands, we introduced a porous wall into boundary-layer flow to retard a flow separation (or equivalently to enhance momentum transfer), and we observed the significant effects of the wall porosity. We also obtained analytically the unstable eigensolutions to corrugated vortex sheets, which are a model for the near-wall streaky flow, at a long-wavelength limit. In this analysis we have elucidated theoretically the destabilization mechanism of the steaks, and we have found that the saddle-type steady state appears as a nonlinearly saturated state of unstable perturbations. Furthermore, we performed the direct numerical simulations of the flow downstream of a backward-facing step, and we have shown the generation mechanism of three-dimensional vortical structures appearing downstream of the step.
We have worked on the stabilization of the saddle (unstable) solutions using the Pyragas' external-force method, and in the numerical experiments of the Couette system we have succeeded in the stabilization of the periodic saddles. In this strategy we can stabilize saddle solutions by small control input. Less

Report

(4 results)
  • 2003 Annual Research Report   Final Research Report Summary
  • 2002 Annual Research Report
  • 2001 Annual Research Report
  • Research Products

    (17 results)

All 2003 2002 2001 Other

All Journal Article (8 results) Publications (9 results)

  • [Journal Article] Linear instability of a corrugated vortex sheet - a model for streak instability2003

    • Author(s)
      G.Kawahara, J.Jimenez, M.Uhlmann, A.Pinelli
    • Journal Title

      Journal of Fluid Mechanics 483

      Pages: 315-342

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Linear instability of a corrugated vortex sheet-a model for streak instability2003

    • Author(s)
      G.Kawahara, J.Jimenez, M.Uhlmann, A.Pinelli
    • Journal Title

      Journal of Fluid Mechanics 483

      Pages: 315-342

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Characterization of near-wall turbulence in terms of equilibrium and periodic solutions2002

    • Author(s)
      G.Kawahara, J.Jimenez, M.Shiba, M.Simens
    • Journal Title

      NASA-Ames/Stanford Center for Turbulence Research Proceedings of the Summer Program 2002

      Pages: 179-190

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Characterization of near-wall turbulence in terms equilibrium and periodic solutions2002

    • Author(s)
      G.Kawahara, J.Jimenez, M.Shiba, M.Simens
    • Journal Title

      NASA-Ames/Stanford Center for Turbulence Research Proceedings of the Summer Program 2002

      Pages: 179-190

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Turbulent shear flow over active and passive porous surfaces2001

    • Author(s)
      J.Jimenez, M.Uhlmann, A.Pinelli, G.Kawahara
    • Journal Title

      Journal of Fluid Mechanics 442

      Pages: 87-117

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Periodic motion embedded in plane Couette turbulence : regeneration cycle and burst2001

    • Author(s)
      G.Kawahara, S.Kida
    • Journal Title

      Journal of Fluid Mechanics 449

      Pages: 291-300

    • NAID

      110003890099

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Three-dimensional vortical structures of the backward-facing step flow at moderate Reynolds numbers2001

    • Author(s)
      S.Yanase, G.Kawahara, H.Kiyama
    • Journal Title

      Journal of the Physical Society of Japan 70・12

      Pages: 3550-3555

    • NAID

      10009124411

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Journal Article] Periodic motion embedded in plane Couette turbulence regeneration cycle and burst2001

    • Author(s)
      G.Kawahara, S.Kida
    • Journal Title

      Journal of Fluid Mechanics 449

      Pages: 291-300

    • NAID

      110003890099

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] G.Kawahara, J.Jimenez, M.Uhimann, A.Pinelli: "Linear instability of a corrugated vortex sheet - a model for streak instability"Journal of Fluid Mechanics. 483. 315-342 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] S.Yanase, G.Kawahara, H.Kiyama: "Evolution of three-dimensionality in a backward-facing step flow"Computational Fluid Dynamics Journal. 66・644. 997-1003 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] G.Kawahara, S.Kida: "Time-periodic solutions for plane Couette flow"Proceedings of International Symposium on Dynamics and Statistion of Cohrerent Structures in Turbulence. 129-140 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] G.Kawahara, J.Jimenez, M.Shiba, M.Simens: "Characterization of near-wall turbulence in terms of equilibrium and periodic solutions"Center for Turbulence Research Proceedings of the Summer Program 2002. 179-190 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] G.Kawahara, J.Jimenez, M.Uhlmann, A.Pinelli: "Linear instability of a corrugated vortex sheet -a model for streak instability"Journal of Fluid Mechanics. (印刷中).

    • Related Report
      2002 Annual Research Report
  • [Publications] 柳瀬, 河原, 木山: "Three-dimensional vortical structures in the backward facing step flow"Journal of the Physicals Society of Japan. Vol.70・No.12. 3550-3555 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] Jimenez, Uhlmann, Pinelli, 河原: "Turbulent shear flow over active and passive porous surfaces"Journal of Fluid Mechanics. Vol.442. 89-117 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] 河原, 木山, 八木: "Vorticity stretching and energy dissipation around a straight vortex tube in a uniform shear flow"JSME International Journal (Ser. B). Vol.44・No.3. 369-377 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] 河原, 木田: "Periodic motion embedded in plane Couette turbulence : regeneration cycle and burst"Journal of Fluid Mechanics. Vol.449. 291-300 (2001)

    • Related Report
      2001 Annual Research Report

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Published: 2001-04-01   Modified: 2016-04-21  

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