Abstract
Flow visualization and hot-wire anemometry were used to examine the effects of indeterminate-origin nozzles on flow in the near field of an otherwise axisymmetric air jet. The jet Reynolds number based on nozzle exit diameter was 19,000. Flow structure was investigated under both unforced and forced conditions where the forcing frequency corresponded to a Strouhal number based on diameter of 0.51. Time-averaged views of the unforced flow showed significant deviations of the jet from axisymmetry. Phase-averaged slices of forced flow strobed with a copper vapor laser revealed strong variations in entrainment along different azimuthal planes. Also, the phase-averaged visualizations showed repeatable coherent longitudinal vortex structures attached to the larger-scale vortex rings normally observed in round jets. When tooth length and number on the nozzle attachments were varied, the stability and propagation patterns of these longitudinal structures could be altered. Nomenclature D = jet exit diameter Euu = power spectral density function for axial velocity fluctuations / = forcing frequency ReD = Reynolds number, UD/v r = radial coordinate StD = Strouhal number, fD/U U = mean nozzle exit velocity Ux = mean axial velocity u'x = rms axial velocity x = axial coordinate /3 = azimuthal angle da = shear-layer vorticity thickness v = kinematic viscosity
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
