Drag reduction by streamwise traveling wave-like Lorenz force in channel flow

Hiroya Mamori, Koji Fukagata

Research output: Contribution to journalConference article

5 Citations (Scopus)

Abstract

Skin-friction drag reduction effect of traveling wave-like wall-normal Lorenz force in a fully developed turbulent channel flow is investigated by means of direct numerical simulation. A sinusoidal profile of the wall-normal body force is assumed as the Lorenz force. While upstream traveling waves reduce the drag in the case of blowing/suction, standing waves reduce it in the case of present forcing. Visualization of vortical structure under the standing wave-like wall-normal Lorenz force reveals that the near-wall streamwise vortices, which increase the skin-friction drag, disappear and spanwise roller-like vortices are generated instead. Three component decomposition of the Reynolds shear stress indicates that the spanwise roller-like vortices contribute to the negative Reynolds shear stress in the region near the wall, similarly to the case of laminar flows. While the analogy between the wall-normal and streamwise forcings can be expected, the statistics are found to exhibit different behaviors due to the difference in the energy flow.

Original languageEnglish
Article number022030
JournalJournal of Physics: Conference Series
Volume318
Issue numberSECTION 2
DOIs
Publication statusPublished - 2011 Jan 1
Event13th European Turbulence Conference, ETC13 - Warsaw, Poland
Duration: 2011 Sep 122011 Sep 15

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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