TY - JOUR
T1 - Predictions of canonical wall-bounded turbulent flows via a modified k–ω equation
AU - Chen, Xi
AU - Hussain, Fazle
AU - She, Zhen Su
N1 - Publisher Copyright:
© 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2017/1/2
Y1 - 2017/1/2
N2 - A major challenge in computation of engineering flows is to derive and improve turbulence models built on turbulence physics. Here, we present a physics-based modified k–ω equation for canonical wall-bounded turbulent flows (boundary layer, channel and pipe), predicting both mean velocity profile (MVP) and streamwise mean kinetic energy profile (SMKP) with high accuracy over a wide range of Reynolds number (Re). The result builds on a multi-layer quantification of wall flows, which allows a significant modification of the k–ω equation. Three innovations are introduced: first, an adjustment of the Karman constant to 0.45 is set for the overlap region with a logarithmic MVP; second, a wake parameter models the turbulent transport near the centreline; third, an anomalous dissipation factor represents the effect of a meso-layer in the overlap region. Then, a highly accurate (above 99%) prediction of MVPs is obtained in Princeton pipes, improving the original model prediction by up to 10%. Moreover, the entire SMKP, including the newly observed outer peak, is predicted. With a slight change of the wake parameter, the model also yields accurate predictions for channels and boundary layers.
AB - A major challenge in computation of engineering flows is to derive and improve turbulence models built on turbulence physics. Here, we present a physics-based modified k–ω equation for canonical wall-bounded turbulent flows (boundary layer, channel and pipe), predicting both mean velocity profile (MVP) and streamwise mean kinetic energy profile (SMKP) with high accuracy over a wide range of Reynolds number (Re). The result builds on a multi-layer quantification of wall flows, which allows a significant modification of the k–ω equation. Three innovations are introduced: first, an adjustment of the Karman constant to 0.45 is set for the overlap region with a logarithmic MVP; second, a wake parameter models the turbulent transport near the centreline; third, an anomalous dissipation factor represents the effect of a meso-layer in the overlap region. Then, a highly accurate (above 99%) prediction of MVPs is obtained in Princeton pipes, improving the original model prediction by up to 10%. Moreover, the entire SMKP, including the newly observed outer peak, is predicted. With a slight change of the wake parameter, the model also yields accurate predictions for channels and boundary layers.
KW - Reynolds-averaged Navier–Stokes
KW - Turbulent boundary layers
KW - turbulence modelling
UR - http://www.scopus.com/inward/record.url?scp=84991037846&partnerID=8YFLogxK
U2 - 10.1080/14685248.2016.1243244
DO - 10.1080/14685248.2016.1243244
M3 - Article
AN - SCOPUS:84991037846
VL - 18
SP - 1
EP - 35
JO - Journal of Turbulence
JF - Journal of Turbulence
SN - 1468-5248
IS - 1
ER -