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Evaluation of the structure function method to compute turbulent dissipation within boundary layers using numerical simulations
Author(s) -
Jabbari Aidin,
Rouhi Amirreza,
Boegman Leon
Publication year - 2016
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2015jc011608
Subject(s) - dissipation , turbulence , isotropy , turbulence kinetic energy , boundary layer , mechanics , boundary (topology) , physics , function (biology) , flow (mathematics) , kinetic energy , kolmogorov microscales , statistical physics , mathematics , classical mechanics , mathematical analysis , k omega turbulence model , thermodynamics , optics , evolutionary biology , biology
Well‐resolved numerical simulations of turbulent open channel flows are analyzed to evaluate the accuracy of the 2nd order structure function method (SFM) in estimating the rate of dissipation of turbulent kinetic energy within boundary layers. The objective is to assess the variation in the 2/3 Kolmogorov constants due to flow anisotropy with distance from the wall. Comparison of the dissipation calculated directly from the numerical data, with that from the SFM shows that usage of the canonical constants, based on the assumption of local isotropy, can result in considerable error (>50%) in the prediction of dissipation when using the vertical or spanwise velocity components. From the numerically calculated dissipation, optimal Kolmogorov 2/3 constants were obtained and empirical relations, which account for near‐wall effects, were proposed. Usage of the optimal constants will improve estimation of the dissipation rate when the SFM is applied to compute dissipation in geophysical boundary‐layer flows.