Willert, Christian und Schanz, Daniel und Novara, Matteo und Geisler, Reinhard und Schroll, Michael und Ribergard, Simon und Schröder, Andreas (2021) Multi-Resolution, Time-Resolved PIV Measurements of a Decelerating Turbulent Boundary Layer near Separation. In: 14th International Symposium on Particle Image Velocimetry - ISPIV 2021. 14th International Symposium on Particle Image Velocimetry – ISPIV 2021, 2021-08-01 - 2021-08-05, Chicago, USA (Virtual). doi: 10.18409/ispiv.v1i1.77.
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Offizielle URL: https://doi.org/10.18409/ispiv.v1i1.77
Kurzfassung
We report on measurements of the time-evolving velocity profile of a turbulent boundary layer subjected to a strong adverse pressure gradient (APG) at Reynolds numbers up to Re_theta ~55000 with an upstream friction Reynolds number exceeding Re_tau ~10000. Near the point of flow separation high-resolution imaging at high camera frame rates captured the time evolving velocity profile using the so-called "profile-PIV" technique in a nested imaging configuration of two cameras operating at different image magnifications. One camera used an image magnification better than unity to resolve the viscous scales directly at the wall while the remainder of the roughly 200 mm thick boundary layer is simultaneous captured by the second camera. In the APG the variance of the stream-wise velocity exhibits no "inner peak" commonly found in turbulent boundary layers without pressure gradient influence. Spectral analysis further shows that the peak energy within the boundary layer shifts away from the wall toward lower frequencies. The overlap between the simultaneously imaged areas allows to assess and, to first order, correct for the effect of spatial smoothing on statistical quantities, spectra and related quantities. A multi-frame cross-correlation algorithm was used to process the extensive database. In addition, a newly developed 2D-2C "Shake-The-Box" algorithm(STB) provided highly resolved particle tracking data beyond the reach of conventional PIV processing.
elib-URL des Eintrags: | https://elib.dlr.de/148594/ | ||||||||||||||||||||||||||||||||
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Dokumentart: | Konferenzbeitrag (Vortrag) | ||||||||||||||||||||||||||||||||
Titel: | Multi-Resolution, Time-Resolved PIV Measurements of a Decelerating Turbulent Boundary Layer near Separation | ||||||||||||||||||||||||||||||||
Autoren: |
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Datum: | August 2021 | ||||||||||||||||||||||||||||||||
Erschienen in: | 14th International Symposium on Particle Image Velocimetry - ISPIV 2021 | ||||||||||||||||||||||||||||||||
Referierte Publikation: | Ja | ||||||||||||||||||||||||||||||||
Open Access: | Ja | ||||||||||||||||||||||||||||||||
Gold Open Access: | Nein | ||||||||||||||||||||||||||||||||
In SCOPUS: | Nein | ||||||||||||||||||||||||||||||||
In ISI Web of Science: | Nein | ||||||||||||||||||||||||||||||||
DOI: | 10.18409/ispiv.v1i1.77 | ||||||||||||||||||||||||||||||||
Status: | veröffentlicht | ||||||||||||||||||||||||||||||||
Stichwörter: | turbulent boundary layers, PIV, adverse pressure gradient, high-speed PIV, profile-PIV, flow separation | ||||||||||||||||||||||||||||||||
Veranstaltungstitel: | 14th International Symposium on Particle Image Velocimetry – ISPIV 2021 | ||||||||||||||||||||||||||||||||
Veranstaltungsort: | Chicago, USA (Virtual) | ||||||||||||||||||||||||||||||||
Veranstaltungsart: | internationale Konferenz | ||||||||||||||||||||||||||||||||
Veranstaltungsbeginn: | 1 August 2021 | ||||||||||||||||||||||||||||||||
Veranstaltungsende: | 5 August 2021 | ||||||||||||||||||||||||||||||||
Veranstalter : | Illinois institute of Technology | ||||||||||||||||||||||||||||||||
HGF - Forschungsbereich: | Luftfahrt, Raumfahrt und Verkehr | ||||||||||||||||||||||||||||||||
HGF - Programm: | Luftfahrt | ||||||||||||||||||||||||||||||||
HGF - Programmthema: | Effizientes Luftfahrzeug | ||||||||||||||||||||||||||||||||
DLR - Schwerpunkt: | Luftfahrt | ||||||||||||||||||||||||||||||||
DLR - Forschungsgebiet: | L EV - Effizientes Luftfahrzeug | ||||||||||||||||||||||||||||||||
DLR - Teilgebiet (Projekt, Vorhaben): | L - Virtuelles Flugzeug und Validierung | ||||||||||||||||||||||||||||||||
Standort: | Göttingen , Köln-Porz | ||||||||||||||||||||||||||||||||
Institute & Einrichtungen: | Institut für Antriebstechnik > Triebwerksmesstechnik Institut für Aerodynamik und Strömungstechnik > Experimentelle Verfahren, GO | ||||||||||||||||||||||||||||||||
Hinterlegt von: | Willert, Dr.phil. Christian | ||||||||||||||||||||||||||||||||
Hinterlegt am: | 11 Feb 2022 08:40 | ||||||||||||||||||||||||||||||||
Letzte Änderung: | 24 Apr 2024 20:46 |
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