A dual-grid hybrid RANS/LES model for under-resolved near-wall regions and its application to heated and separating flows

P. Nguyen, J. Uribe, I. Afgan, D. Laurence

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

A hybrid RANS/LES model is presented, in which RANS and LES contributions to the subgrid-scale (SGS) Reynolds stresses are computed on two distinct grids and are seamlessly blended. The instantaneous, fluctuating SGS Reynolds stress field is supported by a statistical RANS eddy viscosity model in regions where the LES grid is considered as coarse. The present hybrid model acts as a near-wall correction to the LES, while it retains the fluctuating nature of the flow field. The dual computation enables the LES to be run on grids with very low wall-normal resolution, while the RANS model is solved on wall-refined high-aspect ratio grids. Predictions of a heated plane channel flow for a range of Reynolds numbers are generally improved in comparison to conventional LES, with the wall-nearest grid point lying far in the logarithmic layer. Current work also includes a validation on a ribbed channel flow with high blockage ratio, where results are very promising.

Original languageBritish English
Title of host publicationTHMT 2018 - Proceedings of the 9th International Symposium on Turbulence Heat and Mass Transfer
PublisherBegell House Inc.
Pages605-616
Number of pages12
ISBN (Electronic)9781567004687
DOIs
StatePublished - 2018
Event9th International Symposium on Turbulence Heat and Mass Transfer, THMT 2018 - Rio de Janeiro, Brazil
Duration: 10 Jul 201813 Jul 2018

Publication series

NameProceedings of the International Symposium on Turbulence, Heat and Mass Transfer
Volume2018-July
ISSN (Electronic)2377-2816

Conference

Conference9th International Symposium on Turbulence Heat and Mass Transfer, THMT 2018
Country/TerritoryBrazil
CityRio de Janeiro
Period10/07/1813/07/18

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