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
Velocity distribution in compound channel flows by numerical modeling
TL;DR: In this paper, the authors examined the problem of predicting uniform turbulent flow in a compound channel with the nonlinear k-e model, which is capable of predicting the secondary currents caused by the anisotropy of normal turbulent stresses, as they determine the transverse momentum transfer.
Journal ArticleDOI
Contribution to single-point closure Reynolds-stress modelling of inhomogeneous flow
TL;DR: In this paper, it is shown that wall-normal-free Reynolds-stress models can be reformulated as a projection on a tensorial basis that includes the inhomogeneity direction unit vector, suggesting that the theory of the redistribution tensor closure should be revised by taking into account inhomogeneous effects in the tensorial integrity basis used for its representation.
A critical comparison of turbulence models for homogeneous shear flows in a rotating frame
TL;DR: In this paper, a variety of turbulence models, including five second-order closure models and four two-equation models, are tested for the problem of homogeneous turbulent shear flow in a rotating frame.
Journal ArticleDOI
Near-wall two-equation model for compressible turbulent flows
TL;DR: In this article, a near-wall two-equation turbulence model of the K- epsilon type is developed for the description of high-speed compressible flows, where the Favre-averaged equations of motion are solved in conjunction with modeled transport equations for the turbulent kinetic energy and solenoidal dissipation wherein a variable density extension of the asymptotically consistent nearwall model of So and co-workers is supplemented with new dilatational models.
Journal ArticleDOI
A methodology to quantify the nonlinearity of the Reynolds stress tensor
TL;DR: In this article, the dependence of the Reynolds stress tensor on mean kinematic tensor basis is quantified using tensor decomposition theorems, which allow to extract from the anisotropic Reynolds tensor the part that is linear or nonlinear in the strain rate tensor D, and the parts that are in-phase (sharing the same eigenvectors) and out-of-phase with strain rate D. The results have shown that the tensorial form of the linear Boussinesq hypothesis is not a good assumption even in the region
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.