Journal ArticleDOI
A dynamic subgrid‐scale eddy viscosity model
TLDR
In this article, a new eddy viscosity model is presented which alleviates many of the drawbacks of the existing subgrid-scale stress models, such as the inability to represent correctly with a single universal constant different turbulent fields in rotating or sheared flows, near solid walls, or in transitional regimes.Abstract:
One major drawback of the eddy viscosity subgrid‐scale stress models used in large‐eddy simulations is their inability to represent correctly with a single universal constant different turbulent fields in rotating or sheared flows, near solid walls, or in transitional regimes. In the present work a new eddy viscosity model is presented which alleviates many of these drawbacks. The model coefficient is computed dynamically as the calculation progresses rather than input a priori. The model is based on an algebraic identity between the subgrid‐scale stresses at two different filtered levels and the resolved turbulent stresses. The subgrid‐scale stresses obtained using the proposed model vanish in laminar flow and at a solid boundary, and have the correct asymptotic behavior in the near‐wall region of a turbulent boundary layer. The results of large‐eddy simulations of transitional and turbulent channel flow that use the proposed model are in good agreement with the direct simulation data.read more
Citations
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Journal ArticleDOI
RANS and LES computations of the tip-leakage vortex for different gap widths
TL;DR: In this paper, the influence of the gap width on the development of the tip-leakage vortex is investigated. And a law that matches the vortex trajectory from the leading edge to the mid-chord is proposed to determine, in case of cavitation, if the tip vortex will interact with the walls and cause erosion.
Journal ArticleDOI
Numerical simulation of the wake of a towed sphere in a weakly stratified fluid
TL;DR: In this article, the authors used large-eddy simulation to compute the late wake of a sphere towed at constant speed through a non-stratified and a uniformly stratified fluid.
On the parameterization of surface roughness at regional scales
TL;DR: In this paper, the surface roughness and blending height at regional scales, under neutral atmospheric stability, is studied and tested using a suite of large-eddy simulations (LES) over surfaces with varying roughness height and multiple variability scales, including random tiling of patches with a wide distribution of length scales.
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A Review of Variational Multiscale Methods for the Simulation of Turbulent Incompressible Flows
TL;DR: A review of variational multiscale (VMS) methods for simulating turbulent incompressible flows can be found in this paper, where the derivation of different VMS methods is presented in some detail and their relation among each other and also to other discretizations is discussed.
Journal ArticleDOI
A similarity theory of locally homogeneous and isotropic turbulence generated by a Smagorinsky-type LES
TL;DR: In this article, a Kolmogorov-type similarity theory of locally homogeneous and isotropic turbulence generated by a Smagorinsky-type large-eddy simulation (LES) at very large LES Reynolds numbers is developed and discussed.
References
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Journal ArticleDOI
General circulation experiments with the primitive equations
TL;DR: In this article, an extended period numerical integration of a baroclinic primitive equation model has been made for the simulation and the study of the dynamics of the atmosphere's general circulation, and the solution corresponding to external gravitational propagation is filtered by requiring the vertically integrated divergence to vanish identically.
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Turbulence statistics in fully developed channel flow at low reynolds number
TL;DR: In this article, a direct numerical simulation of a turbulent channel flow is performed, where the unsteady Navier-Stokes equations are solved numerically at a Reynolds number of 3300, based on the mean centerline velocity and channel half-width, with about 4 million grid points.
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Renormalization group analysis of turbulence I. Basic theory
Victor Yakhot,Steven A. Orszag +1 more
TL;DR: In this article, a dynamic renormalization group (RNG) method for hydrodynamic turbulence was developed, which uses dynamic scaling and invariance together with iterated perturbation methods, allowing us to evaluate transport coefficients and transport equations for the large scale (slow) modes.
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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.
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On Turbulent Flow Near a Wall
TL;DR: In this paper, the authors defined the distance from wall pipe radius pipe diameter mean local velocity parallel to wall velocity fluctuations parallel and normal to flow mass density coefficient of viscosity shear stress velocity correlation coefficient mixing length universal constant in I = Ky modified universal constant eddy viscosities size of roughness friction factor = 8rw/p V 2