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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For Peer Review Only Evaluation of turbulence models in MHD channel and square duct flows
Brian Thomas,Vanka +1 more
TL;DR: In this article, several low and high Reynolds number versions of k-ε and Reynolds stress turbulence models have been evaluated in a channel and a square duct flow with and without a magnetic field by comparing the predictions with direct numerical simulations data.
Journal ArticleDOI
A 3D finite element model for free-surface flows
TL;DR: In this article, a 3D finite element model for free-surface flows is presented, which uses non-hydrostatic pressure and the eddy viscosities from the conventional linear turbulence model to account for the secondary effects generated by strong channel curvature in natural rivers with meandering open channels.
Proceedings ArticleDOI
A new physically-based fully-realizable nonequilibrium reynolds stress closure for turbulent Flow RANS modeling
TL;DR: Based on the physics underlying turbulence anisotropy in the equilibrium and nonequilibrium limits, a new physically-based, fully-realizable, none-ilibrium k i † RANS model has been developed as discussed by the authors.
Journal ArticleDOI
Cfd for aerodynamic turbulent flows: progress and problems
TL;DR: In this paper, the authors review some recent strategies for obtaining more reliable models with especial focus on cubic non-linear eddy viscosity models and stress-transport schemes which comply with the two-component limit.
Journal ArticleDOI
On turbulence modelling and the transition from laminar to turbulent flow
TL;DR: In this paper, it was argued that turbulence might always be regarded as a non-Newtonian effect, to a degree that is dependent only on the particular fluid in question.
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.