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

Hiroya Mamori, Koji Fukagata

Research output: Contribution to journalArticle

4 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

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drag reduction
channel flow
traveling waves
friction drag
rollers
skin friction
Reynolds stress
vortices
standing waves
shear stress
blowing
suction
direct numerical simulation
laminar flow
upstream
drag
statistics
decomposition
profiles

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Drag reduction by streamwise traveling wave-like Lorenz force in channel flow. / Mamori, Hiroya; Fukagata, Koji.

In: Journal of Physics: Conference Series, Vol. 318, No. SECTION 2, 022030, 2011.

Research output: Contribution to journalArticle

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