Vortical Structure of Plane Jet Issuing from a Sinusoidal Wavy Nozzle

Sang Joon Lee
Hak Lim Kim
S. Rajagopalan
Pohang University of Science and Technology

These images show the flow structure of the plane jet issuing from a sinusoidal wavy nozzle (utmost left side of each image) in three horizontal planes at z = 0, 10, 15mm. The upper three images exhibit the propagation of vortices from the wave edge (z=15mm) to the jet center plane (z=0mm) of the in-phase sinusoidal nozzle in which the upper and lower sides of the sinusoidal nozzle have the same wavy shape without phase difference. The lower images show the large-scale vortices of the jet from the 180° out-of-phase sinusoidal nozzle.

Peculiar vortex structure is formed due to interaction and central migration of large-scale vortices shed from the sinusoidal edge of the nozzle as the flow goes downstream. Compared to the in-phase sinusoidal nozzle jet, the 180° out-of-phase nozzle jet exhibits extension of potential core region and effective suppression of turbulent mixing.

Phases of plane jet

explanatory charts

This work was financially supported by KOSEF (Korea Science and Engineering Foundation.

The image has not been published.