Response of high subsonic jet to nonaxisymmetric disturbances

A. Bayliss, L. Maestrello

Research output: Contribution to conferencePaper

1 Scopus citations

Abstract

A model of sound generated in a high subsonic (Mach 0. 9) circular jet is solved numerically in cylindrical coordinates for nonaxisymmetric disturbances. The jet is excited by transient mass injection by a finite duration pulse via a modulated ring source. The nonaxisymmetric solution is computed for long times after the initial disturbance has exited the computational domain. The long time behavior of the jet is dominated by vorticity and pressure disturbances generated at the nozzle lip and growing as they convect downstream in the jet. These disturbances generate sound as they propagate. The primary nonaxisymmetric effect that we simulate is that of a flapping mode where regions of high and low pressure alternate on opposite sides of the jet. The predominant feature of this mode is the appearance of relatively large deviations of the pressure from the ambient pressure on opposite sides of the jet and the convection of these regions downstream. We illustrate flow field, near field and far field data. Important nonaxisymmetric characteristics of the near and flow field disturbances include roughly periodic pressure elevations and depressions at opposite values of the azimuthal angle ψ. These correspond to pressure disturbances propagating in the axial direction. The azimuthal velocity exhibits a sinusoidal dependence on ψ with similar roughly periodic disturbances. For every azimuthal angle ψ the jet radiation peaks about 30° from the jet axis, however there is now a pronounced dependence of the far field radiation pattern on ψ.

Original languageEnglish (US)
DOIs
StatePublished - Jan 1 1997
Event3rd AIAA/CEAS Aeroacoustics Conference, 1997 - Atlanta, United States
Duration: May 12 1997May 14 1997

Other

Other3rd AIAA/CEAS Aeroacoustics Conference, 1997
CountryUnited States
CityAtlanta
Period5/12/975/14/97

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Aerospace Engineering

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    Bayliss, A., & Maestrello, L. (1997). Response of high subsonic jet to nonaxisymmetric disturbances. Paper presented at 3rd AIAA/CEAS Aeroacoustics Conference, 1997, Atlanta, United States. https://doi.org/10.2514/6.1997-1580