Abstract
The near flow field of small aspect ratio elliptic turbulent free jets (issuing from nozzle and orifice) was experimentally studied using a 2D PIV Two point velocity correla tions in these jets revealed the extent and orientation of the large scale structures in th e major and minor planes. The spatial filtering of the instantaneous velocity field using Gaussian convolution kernel shows that while a single large vortex ring circumscribing the jet seems to be present at the exit of nozzle, the orifice jet exhibited a number of smaller vortex ring pairs close to jet exit. The smaller length scale observed in the case of the orifice jet is rep resentative of the smaller azimuthal vor tex rings that generate axial vortex field as they are convected. This results in the axis-switching in th e case of orifice jet and may have a mechanism differ ent from the self induction process as observed in the case of contoured nozzle jet flow.
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Ramesh, G,: He received his M.Sc. (Eng) in Instrumentation engineering in 1998 and Ph.D. in Instrumentation engineering in 2004 from Indian Institute of Science, Bangalore. He works in the Experim ental Aerodynamics Division of National Aerospace laboratories, Bangalore, India. His areas of interest are Quantitative visualization, LDV and Wind tunnel in strumentation,
Venkatakrishnan, L.: He received his M.Tech in 1991 in Aerospace engineering from Indi an Institute of Technology Bombay and his Ph.D, in 1997 from Indian Institute of Science, Bangalore. He works in the Experimental Aerodynamics Division of National Aerospace laboratories, Bangalore, India. His research interests are flow diagnostics and aeroacoustics.
Prabhu, A.: He received his M.Tech, in Aeronautical engineering in 1963 from Indian Institute of Science (IISc) and PhD in Aerospace in 1971 from the same institute, He is presently worki ng as an emeritus professor in Aerospace Department after his retirement from service as profess or at lI Sc. His research interests are turbulence in lab scales as well as in the atmosphere.
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Ramesh, G., Venkatakrishnan, L. & Prabhu, A. PIV studies of large scale structures in the near field of small aspect ratio elliptic Jets. J Vis 9, 23–30 (2006). https://doi.org/10.1007/BF03181565
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DOI: https://doi.org/10.1007/BF03181565