Abstract:
An experimental investigation has been carried out to analyze the jet development and
performance characteristics issuing from different configurations of annular nozzles at Re
= 4e4, 8.4e4, and 1.2e5. Yaw-meter pressure measurements were carried out along the jet
centerline for various vertical distances to quantify the potential core and characteristic
decay of the jets. Flow visualization was performed by vector plotting to analyze jet
structure at different cross-sections along the jet axis, which was used to study the
behaviour of the flow development. The flow features reveal that the axisymmetric annular
structure of the jet results in enhanced mixing of the jet. It is also evident from the yaw
meter measurement that the jet spread is 50% and 20% lower than Re = 1.2e5 for Re = 4e4
and 8.4e4, respectively. For a particular Reynolds number, in most of the cases, the spread
rate in an annular jet was decreased. Overall, the magnitude of centerline velocity in
annular jets has also decreased. Furthermore, the existence of a potential core is found in
free jet only.
