Effect of Streamwise Streaky Structures on Turbulization of a Circular Jet

Development of a free round jet at different conditions at the nozzle exit under an acoustic action

“…These distributions of mean and §uctuating §ow velocities, typical of classical round jet, well comply with previously reported data [14,15]. Considering the smoke visualization data, in the classical jet, one can distinctly observe, in the general view, ring vortices (Fig.…”

“…The development and turbulization mechanisms of classical laminar round jet §ow were previously examined in [14,15]. The tests performed on the new setup con¦rmed previous results.…”

“…1). A detailed description of the experimental procedure used in the present study is given in [15]; in that study, this procedure was used to examine the development and turbulization mechanism of the laminar jet. Like in the present study, in [15], the action of an acoustic disturbance produced by dynamic loudspeaker (10) on the jet structure was examined.…”

“…A detailed description of the experimental procedure used in the present study is given in [15]; in that study, this procedure was used to examine the development and turbulization mechanism of the laminar jet. Like in the present study, in [15], the action of an acoustic disturbance produced by dynamic loudspeaker (10) on the jet structure was examined. The same procedure was also used to synchronize the shedding of Kelvin Helmholtz vortices with short infrared (IR) laser pulses used to stroboscopically register and ¦lm with a videocamera the interaction dynamics of ring vortices with streaky structures.…”

“…The streamwise structures originate inbetween neighboring vortex rings; they largely a¨ect the mixing processes and §ow dynamics. In [14,15], it was shown that streamwise structures play an important role in the jet turbulization mechanism in which jet turbulization occurs due the interaction of streamwise structures with ring vortices. The latter interaction leads to three-dimensional (3D) distortion of these vortices and to emergence of azimuthal outbursts in the form of˜-or Ÿ-shaped vortices; secondary disintegration of these outbursts ¦nally results in jet turbulization.…”