Journal ArticleDOI
On nonlinear K-l and K-ε models of turbulence
Reads0
Chats0
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
More filters
DissertationDOI
Eddy-resolving simulations of the flow around a vertical tail plane
TL;DR: In this article, a flow detaching from a backward rounded ramp is performed in order to assess RANS performance, and the analysis shows that RANS cannot predict the same level of production of turbulent kinetic energy in the detached flow region, discouraging flow mixing, and delaying flow reattachment and recovery.
Analysis of various non-linear k-ε models accuracy to predict flow field and pollutant dispersion around a model building
TL;DR: The analysis of various non-linear k-ε models accuracy to predict flow field and pollutant dispersion around a model building, Modares Mechanical Engineering, Vol. 14, No. 6, pp. 165-174, 2014 as discussed by the authors.
Proceedings ArticleDOI
Effect of Higher-Order Hydrodynamics on Separated Flow Simulation
TL;DR: In this paper, a subcritical flow over the cylinder case is used to demonstrate the benefit of using higher-order hydrodynamic equations for separated turbulent flow simulation, and it is found that the Burnett approach indeed enhances the viscous mixing process and therefore improves the prediction of separation zone length over the NavierStokes approach.
Posted Content
Data-driven RANS closures for three-dimensional flows around bluff bodies
TL;DR: In this paper, the authors apply the data-driven RANS closure modeling framework to fully three-dimensional, high Reynolds number flows: namely wall-mounted cubes and cuboids at Re=40,000, and a cylinder at Re =140,000.
References
More filters
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.