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Numerical study of fluidic injection for noise reduction

Åberg, Magnus LU ; Szász, Robert-Zoltán LU ; Fuchs, Laszlo LU and Gutmark, Ephraim (2007) 45th AIAA Aerospace Sciences Meeting 2007 In Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting p.1-11
Abstract
We investigate the ability of fluidic injection to control the noise of a model gas-turbine nozzle exhaust. The work is conducted using a hybrid method of LES for the flow field and Lighthill's acoustic analogy for the acoustic field. The impact of injection on the flow development in terms of coherent structures and characteristic frequencies is evaluated. The main results show that a low momentum ratio fluidic injection can trigger a vortex pairing mechanism, resulting in energy transfer to a sub-harmonic of the jet preferred shedding frequency. This changes the development and structure of the flow. The corresponding acoustic sources are shown to be significantly damped. For large directivity angles, the spectral distribution and... (More)
We investigate the ability of fluidic injection to control the noise of a model gas-turbine nozzle exhaust. The work is conducted using a hybrid method of LES for the flow field and Lighthill's acoustic analogy for the acoustic field. The impact of injection on the flow development in terms of coherent structures and characteristic frequencies is evaluated. The main results show that a low momentum ratio fluidic injection can trigger a vortex pairing mechanism, resulting in energy transfer to a sub-harmonic of the jet preferred shedding frequency. This changes the development and structure of the flow. The corresponding acoustic sources are shown to be significantly damped. For large directivity angles, the spectral distribution and reduction of Sound Pressure Level is in good agreement with experiments. (Less)
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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Model gas-turbine nozzle exhaust, Fluidic injection, Lighthill's acoustic analogy
in
Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting
pages
1 - 11
publisher
American Institute of Aeronautics and Astronautics
conference name
45th AIAA Aerospace Sciences Meeting 2007
external identifiers
  • scopus:34250867937
ISBN
978-1-56347-890-1
language
English
LU publication?
yes
id
1efd6f5c-f2a0-428d-aa6d-a2e9ac18e920 (old id 643257)
date added to LUP
2007-12-04 13:57:30
date last changed
2017-08-20 04:49:47
@inproceedings{1efd6f5c-f2a0-428d-aa6d-a2e9ac18e920,
  abstract     = {We investigate the ability of fluidic injection to control the noise of a model gas-turbine nozzle exhaust. The work is conducted using a hybrid method of LES for the flow field and Lighthill's acoustic analogy for the acoustic field. The impact of injection on the flow development in terms of coherent structures and characteristic frequencies is evaluated. The main results show that a low momentum ratio fluidic injection can trigger a vortex pairing mechanism, resulting in energy transfer to a sub-harmonic of the jet preferred shedding frequency. This changes the development and structure of the flow. The corresponding acoustic sources are shown to be significantly damped. For large directivity angles, the spectral distribution and reduction of Sound Pressure Level is in good agreement with experiments.},
  author       = {Åberg, Magnus and Szász, Robert-Zoltán and Fuchs, Laszlo and Gutmark, Ephraim},
  booktitle    = {Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting},
  isbn         = {978-1-56347-890-1},
  keyword      = {Model gas-turbine nozzle exhaust,Fluidic injection,Lighthill's acoustic analogy},
  language     = {eng},
  pages        = {1--11},
  publisher    = {American Institute of Aeronautics and Astronautics},
  title        = {Numerical study of fluidic injection for noise reduction},
  year         = {2007},
}