Volume 1, 1996Vortex flows an related numerical methods II
|553 - 564
|15 August 2002
Three-dimensional vorticity dynamics in a coflowing turbulent jet subjected to axial and azimuthal perturbations
Department of Applied Mechanics and Engineering Sciences University of California, San Diego La Jolla, CA 92093-0411, USA
The effect of axial and azimuthal forcing on the spreading and mixing characteristics in the near field (x/D<13) of a coflowing, turbulent (Re>2000) water jet is studied by means of planar, laser induced fluorescence (PLIF) visualizations. Measurements of both the initial spreading rate of the jet and the decay of the concentration along the centerline of the jet show a marked increase in the mixing of the jet as a result of the axial forcing. The mixing enhancement, which is shown to depend on the wavenumber of the azimuthal forcing, the frequency of the axial forcing, and the Reynolds number of the jet, results from the formation of vortex loops caused by the global induction of the jet's vorticity. This vortex induction mechanism appears to be similar to the vorticity modes earlier found in laminar coflowing jets (Lasheras et al., Lect. Appl. Math., 28, 1991).
© EDP Sciences, ESAIM, 1996
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.