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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Multidimensional Predictions of In-Cylinder Turbulent Flows: Contribution to the Assessment of k-ε Turbulence Model Variants for Bowl-in-Piston Engines
TL;DR: In this paper, a mean-flow and turbulence simulation in a motored model engine with a compression ratio of 6.7 was performed using a non-commercial CFD code that was originally developed by the authors.
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Numerical simulation of pool boiling on smooth, vertically aligned tandem tubes
TL;DR: In this paper, a numerical simulation of atmospheric pool boiling on tandem, inclined, electrically heated circular tubes is performed, where an Eulerian-Eulerian description of the two-phase flow formulations is adopted together with a Rensselaer Polytechnic Institute nucleate boiling model to account for the heat and mass transfer in the boiling phenomenon.
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Prediction of a particle-laden turbulent channel flow: Examination of two classes of stochastic dispersion models
TL;DR: In this article, a particle-laden turbulent channel flow using a generalized Langevin model (GLM) and a normalized dispersion model is computed and compared to Direct Numerical Simulation (DNS) data.
Journal ArticleDOI
Investigation of a two-equation turbulent heat transfer model applied to ducts
Masoud Rokni,Bengt Sundén +1 more
TL;DR: In this paper, a non-linear eddy viscosity model is combined with a two-equation heat flux model with the eddy diffusivity concept, and the ratio between the time-scales (temperature to velocity) is found to be approximately 0.7.
Renormalization Group (RG) in Turbulence: Historical and Comparative Perspective
TL;DR: In this paper, the authors discuss the relevance and application of renormalization group to turbulence modelling, and discuss the technical details of a few selected approaches, concluding with a discussion of the relevance of the renormalisation group to the application of turbulence modelling.
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.