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Turbulent structures and budgets behind permeable ribs

Panigrahi, Pradipta K. und Schröder, Andreas und Kompenhans, Jürgen (2005) Turbulent structures and budgets behind permeable ribs. 6th International Symposium on Particle Image Velocimetry, 2005-09-21 - 2005-09-23, Pasadena, California, (USA).

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Kurzfassung

Different rib geometries are traditionally used to improve the heat transfer and mixing enhancement in different industrial applications i.e. heat exchangers, cooling passages of gas turbine blades and fuel elements of nuclear reactors etc. These types of flows are complex due to the flow separation, recirculation bubble, three dimensionality and unsteadiness. Additional secondary vortical structures are present behind the permeable ribs due to the flow through the perforations. The use of particle image velocimetry (PIV) for these flows is expected to improve the understanding of underlying flow structures. However, the use of PIV for these flows in literature has been limited to mean velocities and their second moment statistics i.e. rms quantities. The present study presents the detailed turbulent statistics i.e. mean and rms velocity, higher order moments, the quadrant decomposition of turbulent shear stress producing motions, large and small scale contributions from wavelet analysis and components of the turbulent kinetic energy budgets i.e. convection, diffusion, dissipation and production etc. from two-component and stereo PIV measurements. The availability of instantaneous velocity field with high spatial resolution in PIV measurements offers new possibilities in calculation of differential quantities required for detailed kinetic energy budget calculation. The flow past different surface mounted permeable rib geometries i.e. solid, slit, split-slit and inclined split-slit ribs have been investigated. The assumptions traditionally used in literature for the calculation of budget terms have been verified by the PIV measurements. The coherent structure statistics calculated using the velocity gradient tensor invariant values, wavelet and quadrant analysis are successful in presentation of large scale and small scale turbulent contributions. Overall, this study demonstrates the effectiveness of PIV technique for the detailed turbulent structures investigation of complex flows.

Dokumentart:Konferenzbeitrag (Vortrag, Paper)
Zusätzliche Informationen: LIDO-Berichtsjahr=2005,
Titel:Turbulent structures and budgets behind permeable ribs
Autoren:
AutorenInstitution oder E-Mail-Adresse der Autoren
Panigrahi, Pradipta K.NICHT SPEZIFIZIERT
Schröder, AndreasNICHT SPEZIFIZIERT
Kompenhans, JürgenNICHT SPEZIFIZIERT
Datum:2005
Referierte Publikation:Nein
In SCOPUS:Nein
In ISI Web of Science:Nein
Seitenbereich:Seite 31
Name der Reihe:CD-ROM Conference Papers
Status:veröffentlicht
Stichwörter:PIV, Boundary layer thickness, Turbulent structures
Veranstaltungstitel:6th International Symposium on Particle Image Velocimetry
Veranstaltungsort:Pasadena, California, (USA)
Veranstaltungsart:internationale Konferenz
Veranstaltungsdatum:2005-09-21 - 2005-09-23
HGF - Forschungsbereich:Verkehr und Weltraum (alt)
HGF - Programm:Luftfahrt
HGF - Programmthema:Starrflügler
DLR - Schwerpunkt:Luftfahrt
DLR - Forschungsgebiet:L AR - Starrflüglerforschung
DLR - Teilgebiet (Projekt, Vorhaben):L - Flugphysik
Standort: Göttingen
Institute & Einrichtungen:Institut für Aerodynamik und Strömungstechnik > Experimentelle Verfahren
Hinterlegt von: Ilka Micknaus
Hinterlegt am:31 Jan 2006
Letzte Änderung:27 Apr 2009 04:56

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