Shehzad, Muhammad und Sun, Bihai und Jovic, Daniel und Ostovan, Yasar und Cuvier, Christophe und Foucaut, Jean Marc und Willert, Christian und Atkinson, Callum und Soria, Julio (2022) Intense large-scale motions in zero and adverse pressure gradient turbulent boundary layers. 20th International Symposium on Application of Laser and Imaging Techniques to Fluid Mechanics, 2022-07-11 - 2022-07-14, Lisbon, Portugal. ISBN 978-989-53637-0-4.
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Offizielle URL: https://www.lisbonsimposia.org/
Kurzfassung
Proper orthogonal decomposition (POD) is used to study coherent structures in wall-bounded turbulent flows. The present study uses POD in turbulent boundary layers to determine the contributions of the intense large-scale motions (LSMs) to the Reynolds stresses. This study uses the 2C-2D PIV measurements of zero pressure gradient turbulent boundary layers (ZPG-TBL) at Re_delta2 = 7750, and adverse pressure gradient turbulent boundary layer (APG-TBL) at beta=2.27 and Re_delta2=16240, where Re_delta2 is the momentum thickness based Reynolds number and beta is the Clauser's pressure gradient parameter. The measurements were obtained in the Laboratoire de Mecanique des Fluides de Lille (LMFL) High-Reynolds-Number (HRN) Boundary Layer Wind Tunnel, Lille, France. The snapshots of the flow field are segregated into those dominated by the intense and mild LSMs based on the intensity of the temporal coefficients of the first POD mode. The intense LSMs are further decomposed into high-momentum (HM) and low-momentum (LM) motions. The relative contributions of the HM motions to the Reynolds stresses are larger near the wall as compared to the LM motions. At the wall-normal distance of the displacement thickness (delta_1), HM and LM motions have similar contributions. Beyond delta_1, the LM motions have larger contributions with their peaks located closer to the displacement thickness height. This shows that in the presence of an APG, the turbulence activity is shifted closer to the displacement thickness height.
elib-URL des Eintrags: | https://elib.dlr.de/187577/ | ||||||||||||||||||||||||||||||||||||||||
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Dokumentart: | Konferenzbeitrag (Vortrag) | ||||||||||||||||||||||||||||||||||||||||
Titel: | Intense large-scale motions in zero and adverse pressure gradient turbulent boundary layers | ||||||||||||||||||||||||||||||||||||||||
Autoren: |
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Datum: | 11 März 2022 | ||||||||||||||||||||||||||||||||||||||||
Referierte Publikation: | Ja | ||||||||||||||||||||||||||||||||||||||||
Open Access: | Ja | ||||||||||||||||||||||||||||||||||||||||
Gold Open Access: | Nein | ||||||||||||||||||||||||||||||||||||||||
In SCOPUS: | Nein | ||||||||||||||||||||||||||||||||||||||||
In ISI Web of Science: | Nein | ||||||||||||||||||||||||||||||||||||||||
ISBN: | 978-989-53637-0-4 | ||||||||||||||||||||||||||||||||||||||||
Status: | veröffentlicht | ||||||||||||||||||||||||||||||||||||||||
Stichwörter: | zero pressure gradient, adverse pressure gradient, turbulent boundary layer, high-momentum and low-momentum, large scale motions, PIV, particle image velocimetry, POD, proper orthogonal decomposition | ||||||||||||||||||||||||||||||||||||||||
Veranstaltungstitel: | 20th International Symposium on Application of Laser and Imaging Techniques to Fluid Mechanics | ||||||||||||||||||||||||||||||||||||||||
Veranstaltungsort: | Lisbon, Portugal | ||||||||||||||||||||||||||||||||||||||||
Veranstaltungsart: | internationale Konferenz | ||||||||||||||||||||||||||||||||||||||||
Veranstaltungsbeginn: | 11 Juli 2022 | ||||||||||||||||||||||||||||||||||||||||
Veranstaltungsende: | 14 Juli 2022 | ||||||||||||||||||||||||||||||||||||||||
HGF - Forschungsbereich: | Luftfahrt, Raumfahrt und Verkehr | ||||||||||||||||||||||||||||||||||||||||
HGF - Programm: | Luftfahrt | ||||||||||||||||||||||||||||||||||||||||
HGF - Programmthema: | Umweltschonender Antrieb | ||||||||||||||||||||||||||||||||||||||||
DLR - Schwerpunkt: | Luftfahrt | ||||||||||||||||||||||||||||||||||||||||
DLR - Forschungsgebiet: | L CP - Umweltschonender Antrieb | ||||||||||||||||||||||||||||||||||||||||
DLR - Teilgebiet (Projekt, Vorhaben): | L - Virtuelles Triebwerk | ||||||||||||||||||||||||||||||||||||||||
Standort: | Köln-Porz | ||||||||||||||||||||||||||||||||||||||||
Institute & Einrichtungen: | Institut für Antriebstechnik > Triebwerksmesstechnik | ||||||||||||||||||||||||||||||||||||||||
Hinterlegt von: | Willert, Dr.phil. Christian | ||||||||||||||||||||||||||||||||||||||||
Hinterlegt am: | 15 Aug 2022 15:35 | ||||||||||||||||||||||||||||||||||||||||
Letzte Änderung: | 24 Apr 2024 20:48 |
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