INSTABILITY OF A ROUND JET SURROUNDED BY AN ANNULAR SHEAR LAYER.

A linear stability analysis of the large-scale structure of a round jet surrounded by an annular shear layer is presented. The region influenced by a disturbance is found to be directly proportional to the wavelength of the disturbance. Disturbance measurements made on the jet centerline tend to select for long wavelength disturbances, while measurements made in the shear layer tend to select for short wavelength disturbances. The change in scaling appears to be responsible for the transition between the ripples which occur near the jet nozzle and the puffs which are observed further downstream. Amplified disturbances exhibit a phase lag across the shear layer, which may account for the spade-like structures evident in flow visualizations of turbulent jets.

Duke Authors

Cited Authors

  • Anderson, R; Bejan, A

Published Date

  • 1985

Published In

  • Journal of Fluids Engineering, Transactions of the ASME

Volume / Issue

  • 107 / 2

Start / End Page

  • 258 - 263

Citation Source

  • SciVal