Journal ArticleDOI
Examples of calculation methods for flow and mixing in stratified fluids
TLDR
In this paper, various mathematical models for predicting the flow and mixing processes in stratified fluids are reviewed, with particular focus on stratified lakes and reservoirs, and various types of prediction methods are introduced, from one-dimensional integral methods to direct simulations of the Navier-Stokes equations.Abstract:
Certain mathematical models for predicting the flow and mixing processes in stratified fluids are reviewed, with particular focus on stratified lakes and reservoirs. The various types of prediction methods are introduced briefly, from one-dimensional integral methods to direct simulations of the Navier-Stokes equations. The paper concentrates on turbulence models for simulating the turbulent momentum, heat, and mass transport terms appearing in the statistical methods employing averaged equations. Models ranging from the simple Prandtl mixing length theory to second-order-closure schemes are discussed. To illustrate the predictive capabilities of the methods, examples are presented of applications of the method covered to a variety of stratified flow situations.read more
Citations
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NEMO ocean engine
TL;DR: The ocean engine of NEMO (Nucleus for European Modelling of the Ocean) is a primitive equation model adapted to regional and global ocean circulation problems as discussed by the authors, which is intended to be a flexible tool for studying the ocean and its interactions with the others components of the earth climate system over a wide range of space and time scales.
Journal ArticleDOI
An improved mixed layer model for geophysical applications
TL;DR: In this article, an improved mixed layer model, based on second-moment closure of turbulence and suitable for application to oceanic and atmospheric mixed layers, is described and tested against observational data from different locations in the global oceans, including high latitudes and tropics.
ADCIRC: An Advanced Three-Dimensional Circulation Model for Shelves, Coasts, and Estuaries. Report 1. Theory and Methodology of ADCIRC-2DDI and ADCIRC-3DL.
TL;DR: In this article, the authors describe the theory, methodology, and verification of the ADCIRC (ADvanced CIRCulation) finite element numerical models, which are used to simulate hydrodynamic circulation along shelves, coasts, and within estuaries.
Journal ArticleDOI
Modeling basin-scale internal waves in a stratified lake
TL;DR: In this paper, a 3D mixed-layer model for surface dynamics with a semi-implicit method similar to the momentum solution in the TRIM code with the addition of quadratic Euler-Lagrange dis- cretization, scalar transport using a conservative flux-limited approach, and elimination of vertical diffusion terms in the governing equations is presented.
Journal ArticleDOI
Second-order turbulence closure models for geophysical boundary layers. A review of recent work
Lars Umlauf,Hans Burchard +1 more
TL;DR: In this paper, a review of recent contributions to second-order turbulence modelling is presented, with an emphasis on models of the coastal ocean, and the model performance is evaluated for a number of idealised entrainment scenarios that are typical for shelf seas: entraining in linearly stratified and two-layer fluids caused by (a) surface wind stress (b) bottom stress due to water motion driven by a barotropic pressure gradient (c) bottom jet.
References
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Journal ArticleDOI
General circulation experiments with the primitive equations
TL;DR: In this article, an extended period numerical integration of a baroclinic primitive equation model has been made for the simulation and the study of the dynamics of the atmosphere's general circulation, and the solution corresponding to external gravitational propagation is filtered by requiring the vertically integrated divergence to vanish identically.
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Development of a turbulence closure model for geophysical fluid problems
George L. Mellor,Tetsuji Yamada +1 more
TL;DR: The second-moment turbulent closure hypothesis has been applied to geophysical fluid problems since 1973, when genuine predictive skill in coping with the effects of stratification was demonstrated as discussed by the authors.
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A stable and accurate convective modelling procedure based on quadratic upstream interpolation
TL;DR: In this paper, a convective modeling procedure is presented which avoids the stability problems of central differencing while remaining free of the inaccuracies of numerical diffusion associated with upstream differencings.
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Progress in the development of a Reynolds-stress turbulence closure
TL;DR: In this article, the authors developed a model of turbulence in which the Reynolds stresses are determined from the solution of transport equations for these variables and for the turbulence energy dissipation rate E. Particular attention is given to the approximation of the pressure-strain correlations; the forms adopted appear to give reasonably satisfactory partitioning of the stresses both near walls and in free shear flows.
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On density effects and large structure in turbulent mixing layers
Garry L. Brown,Anatol Roshko +1 more
TL;DR: In this article, Spark shadow pictures and measurements of density fluctuations suggest that turbulent mixing and entrainment is a process of entanglement on the scale of the large structures; some statistical properties of the latter are used to obtain an estimate of entrainedment rates, and large changes of the density ratio across the mixing layer were found to have a relatively small effect on the spreading angle.