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
Numerical Simulation of Mean Flows and Turbulent Structures of Partly-Vegetated Open-Channel Flows using the Nonlinear k-ε Model
TL;DR: In this article, a numerical modeling of mean flow and turbulence structures of partly-vegetated open-channel flows is presented, where the Reynolds-averaged Navier-Stokes equations with vegetation drag terms are solved numerically using the non-linear k-e model.
Book ChapterDOI
The Modeling of Turbulent Flows with Significant Curvature or Rotation
TL;DR: In this article, the authors provide an impression of the successes and weaknesses of different closure levels when applied to the calculation of flows with appreciable curvature or rotation and some directions for improvement.
Journal ArticleDOI
Estimation of anisotropic k-ϵ model on the backward-facing step flow by LES data base
TL;DR: In this article, the backward facing step flow was computed by k-ϵ model using isotropic and anisotropic expression for Reynolds stress and compared with LES data and discussed.
Journal ArticleDOI
Modeling Turbulence Mechanisms in Flows over Abrupt Drops in Bed Elevation
J. Russell Manson,Gareth Pender +1 more
TL;DR: In this article, a computational study of turbulent free surface flow over an abrupt drop in bed elevation is presented, where different constitutive laws, both linear and a nonlinear, are employed for the turbulent stress-strain relationship.
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.