Gutmark, Ephraim J. und Rask, Olaf R. und Michel, Ulf (2007) How Chevrons Decrease Broadband Jet Noise in Cruise. In: 13th AIAA/CEAS Aeroacoustics Conference (28th AIAA Aeroacoustics Conference) (AIAA-2007-3611). 13th AIAA/CEAS Aeroacoustics Conference (28th AIAA Aeroacoustics Conference), AIAA Papers (AIAA-2007-3611), 2007-05-21 - 2007-05-23, Rome, Italy.
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Kurzfassung
Broadband shock noise is reduced because chevrons increase the shear-layer thickness between the flight stream and the jet. It is shown experimentally and with results of a theory of Michalke that this is directly related to a reduction of the axial variation of the pressure amplitudes in the mean flow field of the jet. Since broadband shock noise is the result of an interaction between the turbulence in a jet and the axial variation of the mean flow field the chevrons yield a reduced noise emission. The effects of chevrons on the sound emission from nozzles operating at underexpanded conditions are demonstrated with experimental results. In a cruise condition with a flight Mach number 0.85, the chevron nozzle yields a lower broadband shock noise. It is shown experimentally as well as with the theory of Michalke that chevrons reduce the shock cell spacing, which explains the higher frequencies for broadband shock noise.
elib-URL des Eintrags: | https://elib.dlr.de/48770/ | ||||||||||||||||
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Dokumentart: | Konferenzbeitrag (Paper) | ||||||||||||||||
Titel: | How Chevrons Decrease Broadband Jet Noise in Cruise. | ||||||||||||||||
Autoren: |
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Datum: | 21 Mai 2007 | ||||||||||||||||
Erschienen in: | 13th AIAA/CEAS Aeroacoustics Conference (28th AIAA Aeroacoustics Conference) | ||||||||||||||||
Referierte Publikation: | Nein | ||||||||||||||||
Open Access: | Nein | ||||||||||||||||
Gold Open Access: | Nein | ||||||||||||||||
In SCOPUS: | Nein | ||||||||||||||||
In ISI Web of Science: | Nein | ||||||||||||||||
Name der Reihe: | AIAA Papers | ||||||||||||||||
Status: | veröffentlicht | ||||||||||||||||
Stichwörter: | Broadband shock noise, chevrons, nozzle serrations, supersonic jets, cabin noise reduction, shear layer thickness | ||||||||||||||||
Veranstaltungstitel: | 13th AIAA/CEAS Aeroacoustics Conference (28th AIAA Aeroacoustics Conference), AIAA Papers (AIAA-2007-3611) | ||||||||||||||||
Veranstaltungsort: | Rome, Italy | ||||||||||||||||
Veranstaltungsart: | internationale Konferenz | ||||||||||||||||
Veranstaltungsbeginn: | 21 Mai 2007 | ||||||||||||||||
Veranstaltungsende: | 23 Mai 2007 | ||||||||||||||||
Veranstalter : | ASSOCIAZIONE ITALIANA DI AERONAUTICA E ASTRONAUTICA | ||||||||||||||||
HGF - Forschungsbereich: | Luftfahrt, Raumfahrt und Verkehr | ||||||||||||||||
HGF - Programm: | Luftfahrt | ||||||||||||||||
HGF - Programmthema: | L VU - Luftverkehr und Umwelt (alt) | ||||||||||||||||
DLR - Schwerpunkt: | Luftfahrt | ||||||||||||||||
DLR - Forschungsgebiet: | L VU - Luftverkehr und Umwelt | ||||||||||||||||
DLR - Teilgebiet (Projekt, Vorhaben): | L - Leiser Luftverkehr (alt) | ||||||||||||||||
Standort: | andere | ||||||||||||||||
Institute & Einrichtungen: | Institut für Antriebstechnik > Triebwerksakustik | ||||||||||||||||
Hinterlegt von: | Michel, Prof. Dr.-Ing. Ulf | ||||||||||||||||
Hinterlegt am: | 21 Jun 2007 | ||||||||||||||||
Letzte Änderung: | 24 Apr 2024 19:11 |
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