Journal article

Coherent large-scale structures from the linearized Navier-Stokes equations

Anagha Madhusudanan, Simon J Illingworth, Ivan Marusic

Journal of Fluid Mechanics | Cambridge University Press (CUP) | Published : 2019

Abstract

The wall-normal extent of the large-scale structures modelled by the linearized Navier–Stokes equations subject to stochastic forcing is directly compared to direct numerical simulation (DNS) data. A turbulent channel flow at a friction Reynolds number of 𝜏Re𝜏=2000 is considered. We use the two-dimensional (2-D) linear coherence spectrum (LCS) to perform the comparison over a wide range of energy-carrying streamwise and spanwise length scales. The study of the 2-D LCS from DNS indicates the presence of large-scale structures that are coherent over large wall-normal distances and that are self-similar. We find that, with the addition of an eddy viscosity profile, these features of the large..

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Grants

Awarded by Australian Research Council


Funding Acknowledgements

The authors are grateful for the financial support of the Australian Research Council. We would also like to thank the Fluid Dynamics Group of the Polytechnic University of Madrid (UPM) for the DNS dataset of Encinar et al. (2018) and Dr W. J. Baars for helpful discussions regarding this work.