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
Flow phenomena and mechanisms in a field-scale experimental meandering channel with a pool-riffle sequence: Insights gained via numerical simulation
Seokkoo Kang,Fotis Sotiropoulos +1 more
TL;DR: In this article, a largeeddy simulation of turbulent flow through a natural-like meandering channel with pool-riffle sequences installed in the St. Anthony Falls Laboratory Outdoor StreamLab is carried out to elucidate the hydrodynamics at bank full flow condition.
Journal ArticleDOI
Large Eddy Simulation of high-Reynolds number flow past a rotating cylinder
TL;DR: In this paper, uniform flow past a rotating cylinder at Re = 140,000 is computed based on Large Eddy Simulation (LES), where the cylinder rotates with different spin ratios varying from a = 0 to a = 2, where a is defined as the ratio of the cylinder's circumferential speed to the free-stream speed.
Journal ArticleDOI
Performance of turbulence models for flows through rough pipes
Sowjanya Vijiapurapu,Jie Cui +1 more
TL;DR: In this paper, the Reynolds-averaged Navier-stokes (RANS) equations were solved along with turbulence models, namely k-e, k-ω, Reynolds stress models (RSM), and filtered Navier−Stokes equations along with Large Eddy Simulation (LES) to study the fully-developed turbulent flows in circular pipes roughened by repeated square ribs with various spacings.
Journal ArticleDOI
Large-eddy simulation of an inclined round jet issuing into a crossflow
TL;DR: In this paper, a series of large-eddy simulations of an inclined round jet issuing into a crossflow were performed at four blowing ratios, BR = 0.1, 0.5, 0,7 and 1.0, and the Reynolds number, Re ǫ = 15,300, based on the crossflow velocity and film cooling hole diameter.
Journal ArticleDOI
Influence of helium mole fraction distribution on the properties of cold atmospheric pressure helium plasma jets
TL;DR: In this article, the influence of helium mole fraction distribution in air on the cold atmospheric plasma jets excited by 1.5 kHz rectangular high voltage pulse is studied, which reveals that the structure of the helium distribution caused by diffusion or by turbulent mixing in turbulent regime determines the characteristics of the cold plasma jets.
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
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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