Journal ArticleDOI
On nonlinear K-l and K-ε models of turbulence
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
On Thermodynamics of Turbulence: Development of First Order Closure Models and Critical Evaluation of Existing Models
Amsini Sadiki,Kolumban Hutter +1 more
TL;DR: In this article, the authors use an averaged entropy inequality and employ it together with an entropy principle to develop thermodynamically consistent rate-dependent turbulence models and governing equations at the first order level for describing the turbulence.
Proceedings ArticleDOI
Comparison of Linear, Non-Linear and Generalized RNG-Based k-epsilon Models for Turbulent Diesel Engine Flows
TL;DR: In this paper, the authors compared linear, non-linear and a generalized renormalization group (RNG) two-equation RANS turbulence models of the k-epsilon form for the prediction of turbulent compressible flows in diesel engines.
Journal ArticleDOI
A Quasi-Realizable Cubic Low-Reynolds Eddy-Viscosity Turbulence Model with a New Dissipation Rate Equation
TL;DR: In this paper, a non-linear relationship of the Reynolds stresses in function of the strain rate and vorticity tensors, with terms up to third order, is developed.
Journal ArticleDOI
Turbulence closure modeling with data-driven techniques: physical compatibility and consistency considerations
TL;DR: This work develops foundational tenets to guide development of ML-enhanced turbulence closure models and it is demonstrated that an iterative training procedure can help ensure certain degree of consistency.
Journal ArticleDOI
Numerical study of pulsatile channel flows undergoing transition triggered by a modelled stenosis
TL;DR: In this paper, the physics of pulsatile flows confined within a 3D channel with a modelled stenosis formed eccentrically on the upper wall using the method of large-eddy simulation (LES).
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.