Flow and noise investigations of a separate flow exhaust system

Mihai Mihaescu, Robert-Zoltán Szász, Laszlo Fuchs, Ephraim Gutmark

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceedingpeer-review

6 Citations (SciVal)


A major component of aircraft noise is the jet noise created by the high velocity hot stream exhausting from a jet engine, interacting with itself and with the surrounding cold air. In the present paper the flow and acoustic fields that are generated by two coaxial jets are considered. Numerically, the problem is divided into a flow related part (Navier-Stokes system of equation) and an acoustic part (an inhomogeneous wave equation). The flow field is handled by well resolved Large Eddy Simulation (LES). The acoustical sources can then be computed from the flow field calculations, on the near-field "source" grid. The acoustic field is solved, on the same or even on a larger separate grid, by using an acoustic approximation with appropriate acoustic boundary conditions. The computed flow and acoustical fields are compared to those measured on the separate flow nozzle test facility. The comparisons in terms of velocity and sound pressure levels are shown to validate the used approach. Frequency spectra of the acoustic density fluctuation are presented in order to indicate the locations where the high- or low- frequency noise dominates. The numerical study is focused as well on the Reynolds number effects on the flow and acoustics. Copyright
Original languageEnglish
Title of host publicationProceedings of the ASME Turbo Expo
PublisherAmerican Society Of Mechanical Engineers (ASME)
Volume6 PART B
Publication statusPublished - 2005
EventASME Turbo Expo 2005 - Gas Turbie Technology: Focus for the Future - Reno-Tahoe, NV, United States
Duration: 2005 Jun 62005 Jun 9

Publication series

Volume6 PART B


ConferenceASME Turbo Expo 2005 - Gas Turbie Technology: Focus for the Future
Country/TerritoryUnited States
CityReno-Tahoe, NV

Subject classification (UKÄ)

  • Fluid Mechanics and Acoustics


  • Jet noise
  • Coaxial jets
  • Cold air


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