A coarse-grained LES model for turbulent channel flow

N. Hu, H. Liu, Z. S. She, F. Hussain

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

A hybrid RANS-LES method based on structural ensemble dynamics (SED) theory is presented, wherein coarse-grained turbulent fluctuation amplitudes are re-normalized using instantaneous values of an order function, i.e. mixing length, in the ensemble-averaged Navier-Stokes (EANS) equation. The re-normalization procedure is applied throughout the channel (at wall friction Reynolds numbers Reτ=1 050 and 2 000), to evade the common problem of log-layer mismatch. The mean and rms velocity profiles show improved agreement with DNS at very coarse grids (40×49×20 for both Re's). The method dissipates turbulent kinetic energy in the bulk flow, and increases turbulent fluctuations in the buffer region, mimicking the physical forcing of the sub-grid scale term. The results demonstrate the feasibility to reconstruct the unsteady effect of wall-bounded flows constrained by order functions.

Original languageEnglish (US)
Title of host publicationRecent Progresses in Fluid Dynamics Research - Proceedings of the Sixth International Conference on Fluid Mechanics, ICFM VI
Pages61-65
Number of pages5
Volume1376
DOIs
StatePublished - Nov 8 2011
EventProceedings of the 6th International Conference on Fluid Mechanics: Recent Progresses in Fluid Dynamics Research, ICFM VI - Guangzhou, China
Duration: Jun 30 2011Jul 3 2011

Other

OtherProceedings of the 6th International Conference on Fluid Mechanics: Recent Progresses in Fluid Dynamics Research, ICFM VI
CountryChina
CityGuangzhou
Period6/30/117/3/11

Keywords

  • channel
  • hybrid RANS/LES method
  • large eddy simulation
  • order functions
  • structural ensemble dynamics

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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