Campus Units

Aerospace Engineering

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

5-10-2019

Journal or Book Title

Journal of Fluid Mechanics

Volume

866

First Page

503

Last Page

525

DOI

10.1017/jfm.2019.80

Abstract

Turbulent flow over a series of increasingly high, two-dimensional bumps is studied by well-resolved large-eddy simulation. The mean flow and Reynolds stresses for the lowest bump are in good agreement with experimental data. The flow encounters a favourable pressure gradient over the windward side of the bump, but does not relaminarize, as is evident from near-wall fluctuations. A patch of high turbulent kinetic energy forms in the lee of the bump and extends into the wake. It originates near the surface, before flow separation, and has a significant influence on flow development. The highest bumps create a small separation bubble, whereas flow over the lowest bump does not separate. The log law is absent over the entire bump, evidencing strong disequilibrium. This dataset was created for data-driven modelling. An optimization method is used to extract fields of variables that are used in turbulence closure models. From this, it is shown how these models fail to correctly predict the behaviour of these variables near to the surface. The discrepancies extend further away from the wall in the adverse pressure gradient and recovery regions than in the favourable pressure gradient region.

Comments

This is a manuscript of an article published as Matai, Racheet, and Paul Durbin. "Large-eddy simulation of turbulent flow over a parametric set of bumps." Journal of Fluid Mechanics 866 (2019): 503-525. DOI: 10.1017/jfm.2019.80. Posted with permission.

Copyright Owner

Cambridge University Press

Language

en

File Format

application/pdf

Published Version

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