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
Computation of Particle-Laden Turbulent Gas Flows Using Two Dispersion Models
X.-Q. Chen,José C. F. Pereira +1 more
TL;DR: In this paper, two Lagrangian particle dispersion models, the conventional stochastic discrete delta function model and a recently developed Stochasticprobabilistic efe ciency-enhanced dispersion (SPEED) model, were used to account for the particle dispersibility induced by gas turbulence.
Journal ArticleDOI
A numerical method for solving the compressible Navier-Stokes equations
TL;DR: A new computer code solving the compressible Navier-Stokes equations using the finite-element method is described and two turbulence models are integrated into the code to compare, evaluate, and ultimately improve model performance.
Journal ArticleDOI
On modelling the Reynolds stress in the context of continuum mechanics
Yu-Ning Huang,Yu-Ning Huang +1 more
TL;DR: In this paper, the authors explore an approach to the constitutive equations for the Reynolds stress, assuming that it is determined by the history of the mean deformation of turbulence but has a fading memory.
Journal ArticleDOI
Exact transport equation for local eddy viscosity in turbulent shear flow
TL;DR: In this article, the exact transport equations for the local eddy viscosity and the length-scale variance were derived theoretically, and a direct numerical simulation of turbulent channel flow was carried out to evaluate statistics such as terms in the transport equations.
Book ChapterDOI
Statistical and Spectral Analysis of Turbulence
TL;DR: The criteria for defining a turbulent flow are varied and nebulous because there is no true definition of turbulence as discussed by the authors, and the criteria most often retained are the random character of the spatial and time fluctuations of the velocities, which reflect the existence of finite characteristic scales of statistical correlation.
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.