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On the Convergence and Scaling of High-Order Statistical Moments in Turbulent Pipe Flow using Direct Numerical Simulations

Bauer, Christian and Feldmann, Daniel and Wagner, Claus (2017) On the Convergence and Scaling of High-Order Statistical Moments in Turbulent Pipe Flow using Direct Numerical Simulations. Physics of Fluids, 29 (12). American Institute of Physics (AIP). DOI: 10.1063/1.4996882 ISSN 1070-6631

Full text not available from this repository.

Official URL: http://aip.scitation.org/doi/10.1063/1.4996882

Abstract

Direct numerical simulations of turbulent pipe flow in a flow domain of length L = 42R, friction Reynolds number in the range of 180 ≤ Reτ ≤ 1500 and two different wall-normal grid refinements were carried out and investigated in terms of turbulent high-order statistics. The phenomenology of large local wall-normal velocity fluctuations (velocity spikes) was discussed by means of time series and instantaneous flow-field realisations. Due to their rare appearance both in space and time, statistical high-order moments take quite a long time to converge. A convergence study was performed and for fully converged statistics the sensitivity of the wall-normal kurtosis component value on the wall as well as the scaling behaviour of high- order statistics was investigated. The streamwise Reynolds stress as well as the streamwise skewness and the wall-normal flatness exhibited logarithmic Reynolds number dependencies in the vicinity of the wall and scaling laws were derived accordingly. In the bulk flow region a sudden increase in magnitude in both the streamwise Reynolds stress and skewness was determined for the largest Reynolds number Reτ = 1500, while the profiles scaled well in wall units for Reτ ≤ 720. Both Reynolds number dependencies in the near-wall and the bulk region could be related to large-scale outer flow motions penetrating the buffer layer. While wavelengths related to larger-scale motions (λz ≈ 3R) were computed for Reynolds numbers up to Reτ = 720 by means of two-dimensional two-point velocity correlations, even larger wavelengths related to very-large- scale motions appeared for Reτ = 1500 and are the probable cause of the sudden increase in magnitude of streamwise Reynolds stress and skewness, respectively. With the aid of instantaneous flow field realisations and conditional averaged statistics, the Reynolds dependency of the wall-normal flatness value at the wall was related to the scaling failure of the streamwise Reynolds stress peak. For the lowest Reynolds number (Reτ = 180), discrepancies between plane channel and pipe flow were found and discussed.

Item URL in elib:https://elib.dlr.de/113493/
Document Type:Article
Additional Information:Physics of Fluids 29, 125105 (2017); Full. Published Online: December 2017; Published by AIP Publishing
Title:On the Convergence and Scaling of High-Order Statistical Moments in Turbulent Pipe Flow using Direct Numerical Simulations
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Bauer, ChristianChristian.Bauer (at) dlr.deUNSPECIFIED
Feldmann, Danieldaniel.feldmann (at) dlr.deUNSPECIFIED
Wagner, ClausClaus.Wagner (at) dlr.deUNSPECIFIED
Date:2017
Journal or Publication Title:Physics of Fluids
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:29
DOI :10.1063/1.4996882
Publisher:American Institute of Physics (AIP)
ISSN:1070-6631
Status:Published
Keywords:DNS, Turbulent Pipe Flow
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Transport
HGF - Program Themes:Terrestrial Vehicles (old)
DLR - Research area:Transport
DLR - Program:V BF - Bodengebundene Fahrzeuge
DLR - Research theme (Project):V - Next Generation Train III (old)
Location: Göttingen
Institutes and Institutions:Institute for Aerodynamics and Flow Technology > Fluid Systems, GO
Deposited By: Bachmann, Barbara
Deposited On:11 Jan 2018 08:48
Last Modified:08 Mar 2018 18:48

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