Predictions of canonical wall-bounded turbulent flows via a modified k–ω equation

Xi Chen, Fazle Hussain, Zhen Su She

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

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.

Original languageEnglish
Pages (from-to)1-35
Number of pages35
JournalJournal of Turbulence
Volume18
Issue number1
DOIs
StatePublished - Jan 2 2017

Keywords

  • Reynolds-averaged Navier–Stokes
  • Turbulent boundary layers
  • turbulence modelling

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