Annular jets of large inner diameter
Abstract
Results of an investigation of annular jets with inner diameters large compared with their outer diameters, performed as part of a study of the effect of wake vortices on the outer mixing region of the basic annular jet, are presented. Schlieren photographs were obtained for an annular jet of diameter ratio 1.5, contraction ratio 18:1 and exit Mach number 0.4, and Strouhal numbers were determined for the peak frequency of the jet and wake-excited vortices. Comparison of the results with those for a conical jet reveals the jet vortices of the basic annular jet to behave like those of the conical jet, while the wake-excited vortices have a constant Strouhal number of 0.30, which is near that of the preferred mode of the jet, resulting in the formation of an additional train of wake-excited vortices in the outer mixing region. A distinct phase shift is also noted across the surface of the wake-excited and jet vortexes, which is attributed to their alternate shedding.
- Publication:
-
Journal of Sound Vibration
- Pub Date:
- April 1980
- DOI:
- 10.1016/0022-460X(80)90632-X
- Bibcode:
- 1980JSV....69..616K
- Keywords:
-
- Annular Flow;
- Jet Mixing Flow;
- Vortices;
- Schlieren Photography;
- Strouhal Number;
- Subsonic Flow;
- Vortex Streets;
- Fluid Mechanics and Heat Transfer