Journal ArticleDOI
On nonlinear K-l and K-ε models of turbulence
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TLDR
In this paper, a nonlinear K-l and K-e model is proposed to predict the normal Reynolds stresses in turbulent channel flow much more accurately than the linear model, and the nonlinear model is shown to be capable of predicting turbulent secondary flows in non-circular ducts.Abstract:
The commonly used linear K-l and K-e models of turbulence are shown to be incapable of accurately predicting turbulent flows where the normal Reynolds stresses play an important role. By means of an asymptotic expansion, nonlinear K-l and K-e models are obtained which, unlike all such previous nonlinear models, satisfy both realizability and the necessary invariance requirements. Calculations are presented which demonstrate that this nonlinear model is able to predict the normal Reynolds stresses in turbulent channel flow much more accurately than the linear model. Furthermore, the nonlinear model is shown to be capable of predicting turbulent secondary flows in non-circular ducts - a phenomenon which the linear models are fundamentally unable to describe. An additional application of this model to the improved prediction of separated flows is discussed briefly along with other possible avenues of future research.read more
Citations
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Journal ArticleDOI
Field investigation of ridge–runnel dynamics on an intertidal mudflat
TL;DR: In this article, the authors investigated flow-parallel linear ridge-runnel (R-R) bedforms composed of mainly cohesive sediments at an intertidal site located at Hills Flats in the Severn Estuary, UK.
Journal ArticleDOI
Dispersion and deposition of particles in a turbulent pipe flow with sudden expansion
Goodarz Ahmadi,Qian Chen +1 more
TL;DR: In this paper, numerical simulations of dispersion and deposition of particles in an axisymmetric turbulent pipe flow with sudden expansion are performed, where the effects of turbulence diffusion, Brownian dispersion, lift force, and gravity are included in the computational model.
Journal ArticleDOI
Predictions of solute transport in a compound channel using turbulence models
TL;DR: In this article, the predicted distributions of solute and Reynolds flux using a k-s model and an algebraic stress model for various injection points near the water surface are used to identify different mixing mechanisms.
Journal ArticleDOI
Direct simulation of turbulent flow in a square duct: Reynolds-stress budgets
TL;DR: In this paper, the authors used the data base from a direct numerical simulation of turbulent flow in a square duct to calculate all the terms in the Reynolds stress transport equations and evaluated a nonlinear turbulence model in its ability to accommodate the anisotropy of the Reynolds tensor in this flow.
Journal ArticleDOI
Computational prediction of flow around highly loaded compressor-cascade blades with non-linear eddy-viscosity models
TL;DR: In this article, a computational study is presented which examines the predictive performance of two variants of a cubic low-Re eddy-viscosity model when applied to the flow around two highly loaded compressor-cascade blades.
References
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Journal ArticleDOI
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.
Journal ArticleDOI
A numerical study of three-dimensional turbulent channel flow at large Reynolds numbers
TL;DR: In this article, the three-dimensional, primitive equations of motion have been integrated numerically in time for the case of turbulent, plane Poiseuille flow at very large Reynolds numbers.
Journal ArticleDOI
Numerical investigation of turbulent channel flow
Parviz Moin,John Kim +1 more
TL;DR: In this article, a large-scale flow field was obtained by directly integrating the filtered, three-dimensional, time dependent, Navier-Stokes equations, and small-scale field motions were simulated through an eddy viscosity model.
Book ChapterDOI
Computational Modeling of Turbulent Flows
TL;DR: In this article, it is shown that direct simulation is not an alternative for practical computation and that the various sophisticated closures suffer from essentially the same problems as the direct simulations and therefore, are limited to homogeneous situations.
Journal ArticleDOI
A Reynolds stress model of turbulence and its application to thin shear flows
Kemal Hanjalic,Brian Launder +1 more
TL;DR: In this paper, the authors provided a model of turbulence which effects closure through approximated transport equations for the Reynolds stress tensor the turbulence energy κ and e.g., the turbulent shear stress does not vanish where the mean rate of strain goes to zero.