Large-eddy simulation of MHD turbulent duct flows using a dynamic subgrid-scale model

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

At low magnetic Reynolds number, turbulent duct flows in a uniform magnetic field are examined using large-eddy simulation to reveal a sidewall effect on the skin friction. The duct has a square cross section and entirely insulated walls. The duct flow has two kinds of boundary layers: Hartmann layer and sidewall layer. The Hartmann layer is located on the wall perpendicular to the magnetic field, while the sidewall layer exists on the wall parallel to the magnetic field. As the magnetic field increases in the range of turbulent flows, the Hartmann layer becomes thin because of the "Hartmann flattening" -flattening effect of the flow by the Lorentz force. The sidewall layer, however, becomes thick because of the turbulence suppression until the laminarization takes place. When the Reynolds number Re based on the hydraulic diameter, molecular viscosity, and bulk velocity is 5300, the Hartmann and sidewall layers are laminarized at the same Hartmann number that is proportional to the magnetic field. When the Hartmann layer is laminarized at Re = 29000, the sidewall layer remains turbulence. This allows the skin friction to become maximum. When the sidewall layer is laminarized, the flow totally becomes laminar and the skin friction becomes minimum.

Original languageEnglish
Title of host publicationCollection of Technical Papers - 38th AIAA Plasmadynamics and Lasers Conference
PublisherAmerican Institute of Aeronautics and Astronautics Inc.
Pages688-704
Number of pages17
ISBN (Print)1563479001, 9781563479007
DOIs
Publication statusPublished - 2007
Event38th AIAA Plasmadynamics and Lasers Conference - Miami, FL, United States
Duration: 2007 Jun 252007 Jun 28

Publication series

NameCollection of Technical Papers - 38th AIAA Plasmadynamics and Lasers Conference
Volume2

Other

Other38th AIAA Plasmadynamics and Lasers Conference
CountryUnited States
CityMiami, FL
Period07/6/2507/6/28

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

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  • Cite this

    Kobayashi, H. (2007). Large-eddy simulation of MHD turbulent duct flows using a dynamic subgrid-scale model. In Collection of Technical Papers - 38th AIAA Plasmadynamics and Lasers Conference (pp. 688-704). (Collection of Technical Papers - 38th AIAA Plasmadynamics and Lasers Conference; Vol. 2). American Institute of Aeronautics and Astronautics Inc.. https://doi.org/10.2514/6.2007-4369