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
Response to “Comment on ‘A dynamic nonlinear subgrid-scale stress model’” [Phys. Fluids 17, 099101 (2005)]
Book ChapterDOI
Transversal Flow Field of Particle-Laden Linear Fluids
TL;DR: In this article, the fundamental issues and their impact on industrial processes, in particular on processes involving particle laden flows, are reviewed and criteria for the existence of secondary flows, criteria for their existence, and general classification and closure approximations for homogeneous and wall-bounded flows are discussed.
Journal ArticleDOI
General applicability of low-reynolds-number two-equation turbulence models to the prediction of open channel flows
TL;DR: In this article, the authors propose a method to solve the problem of the lack of a proper dictionary for the following: https://www.reinforcement.org/index.html
Proceedings ArticleDOI
Unsteady CFD modelling of turbulent flows for electronics
TL;DR: In this article, hybrid CFD methods based on the RANS (Reynolds Averaged Navier-Stokes) and LES (Large Eddy Simulation) equations are applied to two bluff geometries to investigate the potential to make accurate thermal predictions.
Book ChapterDOI
Second-Order Turbulence Modeling
TL;DR: The main objective underlying the practice of Reynolds stress modelling is the search for a closure, at the level of the Reynolds stress and dissipation equations, which may be more universal than eddy-viscosity models thus allowing a successful prediction of the highest number of turbulent flows as discussed by the authors.
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.