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
Simulation of transition and turbulence decay in the Taylor–Green vortex
TL;DR: In this article, a variety of subgrid scale (SGS) models and high-resolution numerical methods are implemented in the framework of both incompressible and compressible fluid flow equations.
Journal ArticleDOI
Experimental and numerical investigation of a three-dimensional vertical-axis wind turbine with variable-pitch
TL;DR: In this paper, a combined experimental and numerical investigation is carried out to study the performance of a micro vertical-axis wind turbine (VAWT) with variable pitch, which involves a low aspect ratio (AR) three straight blades with struts.
Journal ArticleDOI
Large eddy simulation in complex geometric configurations using boundary body forces
TL;DR: In this paper, the Navier-Stokes equations on orthogonal grids are applied independently of the grid by assigning body forces over surfaces that need not coincide with coordinate lines.
Journal ArticleDOI
2.5D large eddy simulation of vertical axis wind turbine in consideration of high angle of attack flow
TL;DR: In this paper, the feasibility and accuracy of three different CFD approaches, namely 2D URANS, 2.5D LES, and 2D large eddy simulations (LES), were investigated in the aerodynamic characterization of straight-bladed VAWT (SBVAWT), with a focus on the capability of the two.5d LES approach in CFD simulation of high angle of attack (AOA) flow.
Journal ArticleDOI
Numerical simulation of turbulence and sediment transport of medium sand
TL;DR: In this paper, a model of sand transport in water is produced by combining a turbulence-resolving large eddy simulation (LES) with a discrete element model (DEM) prescribing the motion of individual grains of medium sand.
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.
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
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