• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Study of Turbulent-Transport Suppression in Magnetohydrodynamic Complex Flow

Research Project

Project/Area Number 08454110
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field 物理学一般
Research InstitutionUniversity of Tokyo

Principal Investigator

YOSHIZAWA Akira  University of Tokyo, Institute of Industrial Science, Professor, 生産技術研究所, 教授 (60011649)

Co-Investigator(Kenkyū-buntansha) YOKOI Nobumitsu  University of Tokyo, Institute of Industrial Science, Research Associate, 生産技術研究所, 助手 (50272513)
HAMBA Fujihiro  University of Tokyo, Institute of Industrial Science, Associate Professor, 生産技術研究所, 助教授 (20251473)
Project Period (FY) 1996 – 1997
Project Status Completed (Fiscal Year 1997)
Budget Amount *help
¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1996: ¥2,100,000 (Direct Cost: ¥2,100,000)
Keywordsturbulence / magnetohydrodynamic fluid / compressibility / transport suppression / 輸送制御
Research Abstract

In this study, we clarified that electric fields, plasma rotation, and compressibility are closely related to the suppression mechanism of turbulent transport in a complex system of magnetohydrodynamic (MHD) flow. The findings are summarized as follows.
(1) In tokamak's high-confinement (H) modes, the turbulent transport was shown to be suppressed through the electric field near the separatrix, specifically, its curvature, in contrast with the previous finding based on the radial electric shear.
(2) In the turbulent-transport suppression, the ratio of the renormalized density variance to the turbulent Mach number was shown to be a critical parameter. In order to deal with compressibility effects accurately, it is necessary to distinguish between acoustic density fluctuations and those arising from entropy fluctuations. For this purpose, a turbulence model consisting of the transport equations for the turbulent energy, its dissipation rate, the compressible part of the turbulent energy, and the entropy variance was constructed usign a two-scale direct-interaction formalism.
(3) The concept of turbulent cross helicity was introduced as a quantity connecting plasma rotation with magnetic fields. Using the concept, it was confirmed that global plasma motion and frame rotation result in the formation of global magnetic fields, and that this mechanism is closely associated with the suppression of turbulent transport in a MHD system. These findings were discussed in the context of H modes in tokamaks and the generation of magnetic fields in accretion disks as well as the occurrence of their bipolar jets.

Report

(3 results)
  • 1997 Annual Research Report   Final Research Report Summary
  • 1996 Annual Research Report
  • Research Products

    (25 results)

All Other

All Publications (25 results)

  • [Publications] Akira.Yoshizawa: "Modeling of Compressible effects onthe Reynolds Stress using a Markovianized two-scale method" Physics of Fluids. 9/10. 3024-3036 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] Akira.Yoshizawa: "Stationary large-scale magnetic fields generated by turbulent motion in a spherical region" Physics of Plasmas. 3/10. 3604-3613 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] Fujihiro.Hamba: "Towards modeling inhomogeneous compressible turbulence using a two-scale statistical theory" Physics of Fluids. 9/9. 2749-2768 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] Nobumitsu.Yokoi: "Large-scale magnetic fields in spiral galaxies viewed from the cross-helicity dynamo" Astronomy and Astrophysics. 311. 731-745 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] Nobumitsu.Yokoi: "Analysis of poloidal rotation and suppression of plasma turbulence using a dynamo model" Journal of the Physical Socety of Japan. 65/8. 2353-2356 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] Akira.Yoshizawa: "Hydrodynamic and Magnetohydrodynamic Turbulent Flows:Modeling and Statistical Theory" Kluwer Academic Publishers(Dordrecht,The Netherlands), 414 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] 吉澤 徴: "乱流の数値流体力学(大宮司久明、三宅裕、吉澤徴偏)" 東京大学出版会, 652 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] A.Yoshizawa, W.W.Liou, N.Yokoi and T.-H.Shin: "Modeling of compressibility effects on the Reynolds stress using a Markovianized two-scale method" Physics of Fluids. 9. 3024 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] A.Yoshizawa and N.Yokoi: "Stationary global magnetic fields generated by turbulent motion in a spherical region" Physics of Plasmas. 3. 3604 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] F.Hamba: "Towards modeling inhomogeneous compressible turbulence modeling using a two-scale statistical theory" Physics of Fluids. 9. 3024 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] N.Yokoi: "Laarge-scale magnetic fields in spiral galaxies viewed from the cross-helicity dynamo" Astronomy and Astrophysics. 311. 731 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] N.Yokoi: "Analysis of poloidal rotation and suppression of plasma turbulence using a dynamo model" Journal of Physical Society of Japan. 65. 2353 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] A.Yoshizawa: Hydrodynamic and Magnetohydrodynamic Turbulent Flows : Modeling and Statistical Theory. Kluwer (Dordrecht), (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1997 Final Research Report Summary
  • [Publications] Akira Yoshizawa: "Modeling of compressible effects on the Reynolds stress using a Markovianized two-scale method" Physics of Fluids. 9/10. 3024-3036 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] Akira Yoshizawa: "Stationary large-scale magnetic fields generated by turbulent motion in a spherical region" Physics of Plasmas. 3/10. 3604-3613 (1996)

    • Related Report
      1997 Annual Research Report
  • [Publications] Fujihiro Hamba: "Towards modeling inhomogeneous compressible turbulence using a two-scale statistical theory" Physics of Fluids. 9/9. 2749-2768 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] Nobumitsu Yokoi: "Large-scale magnetic fields in spiral galaxies viewed from the cross-helicity dynamo" Astronomy and Astrophysics. 311. 731-745 (1996)

    • Related Report
      1997 Annual Research Report
  • [Publications] Nobumitsu Yokoi: "Analysis of poloidal rotation and suppression of plasma turbulence using a dynamo model" Journal of the Physical Socety of Japan. 65/8. 2353-2356 (1996)

    • Related Report
      1997 Annual Research Report
  • [Publications] 吉澤 徴: "乱流の数値流体力学(大宮司久明、三宅裕、吉澤徴偏)" 東京大学出版会, 652 (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] Akira Yoshizawa: "Hydrodynamic and Magnetohydrodynamic Turbulent Flows : Modeling and Statistical Theory" Kluwer Academic Publishers (Dordrecht,The Netherlands), 414 (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] A.Yoshizawa: "Modeling of the dynamic subgrid-scale viscosity in large eddy simulation" Physics of Fluids. 8. 2254-2256 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] A.Yoshizawa: "Stationary large-scale magnetic fields generated by turbulent motion in a spherical region" Physics of Plasmas. 3. 3604-3613 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] F.Hamba: "Modeling of inhomogeneous compressible turbulence using a two-scale statistical theory" Annual Research Briefs,CTR,NASA Ames/Stanford. (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] N.Yokoi: "Large-scale magnetic fields in spiral galaxies viewed from the cross-helicity dynamo" Astronomy and Astrophysics. 311. 731-745 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] N.Yokoi: "Analysis of poloidal rotation and suppression of plasma turbulence using a dynamo model" Journal of the Physical Society of Japan. 65. 2353-2356 (1996)

    • Related Report
      1996 Annual Research Report

URL: 

Published: 1996-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi