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Direct numerical simulation of fully developed turbulent and oscillatory pipe flows at Reτ = 1440

Feldmann, Daniel und Wagner, Claus (2012) Direct numerical simulation of fully developed turbulent and oscillatory pipe flows at Reτ = 1440. Journal of Turbulence, Vol. 13 (32), Seiten 1-28. Tayler & Francis. DOI: 10.1080/14685248.2012.708470. ISSN 1468-5248.

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Offizielle URL: http://dx.doi.org/10.1080/14685248.2012.708470

Kurzfassung

Shear flow turbulence in oscillatory fluid motions is of theoretical interest and practical relevance, since the onset of turbulence can drastically change the transport properties and mixing efficiency. To supplement former theoretical and experimental investigations on the transition to turbulence in Sexl–Womersley (SW) flows, we perform three-dimensional direct numerical simulations (DNS) of oscillatory pipe flows at three Womersley numbers (Wo e {26, 13, 5}) and one constant Reynolds number (Re tau = 1440) based on the friction velocity and the pipe diameter. For this, the incompressible Navier–Stokes equations are solved in cylindrical coordinates using a fourth-order-accurate finite-volume method on staggered grids, motivated by Schumann’s volume balance procedure. We generate a well-correlated high-Reynolds-number initial flow field for the oscillatory flows by means of a DNS of a statistically steady pipe flow at Re tau = 1440 . To underline the reliability of the DNS results for the oscillatory pipe flows, we validate the finite-volume method, the spatial resolution of the computational grid and the length of the computational domain by comparing the results for the statistically steady pipe flow with experimental data obtained by laser Doppler anemometry (LDA). Comparing the statistical moments of the velocity components up to the fourth order shows good agreement with the corresponding LDA data. When started from the turbulent initial velocity field, the oscillatory flows relaminarise or reach a conditionally or fully turbulent state, depending on Wo. The peak flow rates decrease with increasing Wo, while the relaxation phase for the initially steady flow converging to a purely oscillating flow increases with increasing Wo. For the highest Wo considered, the flow completely relaminarises and we do not find any instabilities close to the wall, as expected from former stability analyses. On the other hand, we confirm the existence of turbulent bursts and increasing turbulence intensity during the deceleration phase of the flow and relaminarisation in the acceleration phase for Wo=13 in agreement with experimental results in the literature. By analysing selected terms of the transport equations for the mean and turbulent kinetic energy, we demonstrate the transport of turbulent kinetic energy from the axial to the radial and azimuthal velocity components during flow deceleration.

Dokumentart:Zeitschriftenbeitrag
Zusätzliche Informationen:Version of record first published: 07 Aug 2012
Titel:Direct numerical simulation of fully developed turbulent and oscillatory pipe flows at Reτ = 1440
Autoren:
AutorenInstitution oder E-Mail-Adresse der Autoren
Feldmann, Danieldaniel.feldmann@dlr.de
Wagner, Clausclaus.wagner@dlr.de
Datum:2012
Erschienen in:Journal of Turbulence
Referierte Publikation:Ja
In Open Access:Nein
In SCOPUS:Ja
In ISI Web of Science:Ja
Band:Vol. 13
DOI :10.1080/14685248.2012.708470
Seitenbereich:Seiten 1-28
Verlag:Tayler & Francis
ISSN:1468-5248
Status:veröffentlicht
Stichwörter:Direct numerical simulation (DNS), Sexl-Womersley flow, Oscillatory pipe flow, Turbulent pipe flow
HGF - Forschungsbereich:Luftfahrt, Raumfahrt und Verkehr
HGF - Programm:Luftfahrt
HGF - Programmthema:Starrflügler
DLR - Schwerpunkt:Luftfahrt
DLR - Forschungsgebiet:L AR - Starrflüglerforschung
DLR - Teilgebiet (Projekt, Vorhaben):L - Simulation & Validierung
Standort: Göttingen
Institute & Einrichtungen:Institut für Aerodynamik und Strömungstechnik > Fluidsysteme
Hinterlegt von: Daniel Feldmann
Hinterlegt am:28 Sep 2012 14:31
Letzte Änderung:11 Jul 2013 15:42

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