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

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

Full text not available from this repository.

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

Abstract

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.

Document Type:Article
Additional Information:Version of record first published: 07 Aug 2012
Title:Direct numerical simulation of fully developed turbulent and oscillatory pipe flows at Reτ = 1440
Authors:
AuthorsInstitution or Email of Authors
Feldmann, Danieldaniel.feldmann@dlr.de
Wagner, Clausclaus.wagner@dlr.de
Date:2012
Journal or Publication Title:Journal of Turbulence
Refereed publication:Yes
In Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:Vol. 13
DOI:10.1080/14685248.2012.708470
Page Range:pp. 1-28
Publisher:Tayler & Francis
ISSN:1468-5248
Status:Published
Keywords:Direct numerical simulation (DNS), Sexl-Womersley flow, Oscillatory pipe flow, Turbulent pipe flow
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:Aircraft Research
DLR - Research area:Aeronautics
DLR - Program:L AR - Aircraft Research
DLR - Research theme (Project):L - Simulation & Validation
Location: Göttingen
Institutes and Institutions:Institute of Aerodynamics and Flow Technology > Fluid Systems
Deposited By: Daniel Feldmann
Deposited On:28 Sep 2012 14:31
Last Modified:11 Jul 2013 15:42

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