Generation of exchange flows in estuaries by tidal and gravitational eddy viscosity‐shear covariance (ESCO)
Sign Up to like & getrecommendations! Published in 2017 at "Journal of Geophysical Research"
DOI: 10.1002/2016jc012379
Abstract: We present a systematic analysis of generation mechanisms for exchange flows in partially stratified estuaries using water column (1DV) and width-averaged (2DV) numerical models. We focus on exchange flows generated by eddy viscosity-shear covariance (ESCO).… read more here.
Keywords: viscosity; eddy viscosity; exchange flows; esco ... See more keywords
Zonal Eddy Viscosity Models Based on Machine Learning
Sign Up to like & getrecommendations! Published in 2019 at "Flow, Turbulence and Combustion"
DOI: 10.1007/s10494-019-00011-5
Abstract: A zonal k − ω model is constructed, with the zones created by training a decision tree algorithm. The training data are optimized, model coefficient fields. Coefficient data are binned, with each bin assigned a… read more here.
Keywords: viscosity models; eddy viscosity; zonal eddy; model ... See more keywords
Observational study of tidal mixing asymmetry and eddy viscosity-shear covariance - induced residual flow in the Jiulong River estuary
Sign Up to like & getrecommendations! Published in 2020 at "Continental Shelf Research"
DOI: 10.1016/j.csr.2019.104035
Abstract: Abstract An observation study was conducted at three stations in the inner regime of the Jiulong River estuary to examine the tidal mixing asymmetry and its associated residual flow induced by eddy viscosity-shear covariance (ESCO).… read more here.
Keywords: tidal mixing; mixing asymmetry; flow; eddy viscosity ... See more keywords
Eddy viscosity from bottom Ekman veering profiles
Sign Up to like & getrecommendations! Published in 2020 at "Continental Shelf Research"
DOI: 10.1016/j.csr.2020.104170
Abstract: Abstract ADCP profiles near the sea bed, at a 130 m depth continental shelf, were used to estimate the mean veering of the velocity vectors using a complex correlation coefficient. An analytic expression for the veering… read more here.
Keywords: viscosity; viscosity bottom; bottom ekman; eddy viscosity ... See more keywords
Online Model Adaption of Reduced Order Models for Fluid Flows * *The authors gratefully acknowledge funding from the German Research Foundation (DFG) for the Research Unit ‘Active Drag Reduction’ (AB65/12-1)
Sign Up to like & getrecommendations! Published in 2017 at "IFAC-PapersOnLine"
DOI: 10.1016/j.ifacol.2017.08.1006
Abstract: Abstract In this study an online adaption of reduced order models (ROM) for fluid flows is presented. Often ROMs are stabilized and tuned by use of an eddy viscosity which is identified in the offline… read more here.
Keywords: reduced order; viscosity; research; eddy viscosity ... See more keywords
Three-layer viscoelastic model with eddy viscosity effect for flexural-gravity wave propagation through ice cover
Sign Up to like & getrecommendations! Published in 2018 at "Ocean Modelling"
DOI: 10.1016/j.ocemod.2018.08.007
Abstract: Abstract A three-layer model is presented to simulate gravity wave propagation in an ice-covered sea. Damping from a viscoelastic ice cover and the boundary layer of the water body are considered. This model is shown… read more here.
Keywords: eddy viscosity; three layer; water; model ... See more keywords
Two-point stress–strain-rate correlation structure and non-local eddy viscosity in turbulent flows
Sign Up to like & getrecommendations! Published in 2021 at "Journal of Fluid Mechanics"
DOI: 10.1017/jfm.2020.977
Abstract: Abstract By analysing the Karman–Howarth equation for filtered-velocity fields in turbulent flows, we show that the two-point correlation between the filtered strain-rate and subfilter stress tensors plays a central role in the evolution of filtered-velocity… read more here.
Keywords: non local; eddy viscosity; correlation; strain rate ... See more keywords
The energetics and colour for linearised models of wall turbulence
Sign Up to like & getrecommendations! Published in 2024 at "Journal of Fluid Mechanics"
DOI: 10.1017/jfm.2024.929
Abstract: Abstract By comparing the budget of a data-driven quasi-linear approximation (DQLA) (Holford, Lee & Hwang, J. Fluid Mech., vol. 980, 2024, A12) and direct numerical simulation (DNS) (Lee & Moser, J. Fluid Mech., vol. 860,… read more here.
Keywords: models wall; term; turbulence; dns ... See more keywords
On the accuracy of compressibility transformations
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DOI: 10.1063/5.0242189
Abstract: This study highlights the importance of satisfying the eddy viscosity equivalence below the logarithmic layer, to deriving accurate compressibility transformations. First, we analyze the ability of known transformations to satisfy the eddy viscosity equivalence and… read more here.
Keywords: eddy viscosity; viscosity equivalence; compressibility transformations;
The atmospheric Ekman spiral for piecewise-uniform eddy viscosity
Sign Up to like & getrecommendations! Published in 2024 at "Physica Scripta"
DOI: 10.1088/1402-4896/ad6d1b
Abstract: We investigate the boundary-value problem of atmospheric Ekman flows with piecewise-uniform eddy viscosity. In addition we present a method for finding more general solutions by considering eddy viscosity as an arbitrary step-function. We discuss the… read more here.
Keywords: atmospheric ekman; eddy viscosity; piecewise uniform; uniform eddy ... See more keywords
Forward sensitivity approach for estimating eddy viscosity closures in nonlinear model reduction.
Sign Up to like & getrecommendations! Published in 2020 at "Physical review. E"
DOI: 10.1103/physreve.102.043302
Abstract: In this paper, we propose a variational approach to estimate eddy viscosity using forward sensitivity method (FSM) for closure modeling in nonlinear reduced order models. FSM is a data assimilation technique that blends model's predictions… read more here.
Keywords: approach; model; forward sensitivity; eddy viscosity ... See more keywords