scholarly journals Large-Eddy Simulation of Stably Stratified Atmospheric Boundary Layer Turbulence: A Scale-Dependent Dynamic Modeling Approach

2006 ◽  
Vol 63 (8) ◽  
pp. 2074-2091 ◽  
Author(s):  
Sukanta Basu ◽  
Fernando Porté-Agel
Keyword(s):  
Boundary Layers ◽  
Temperature Fields ◽  
Scale Model ◽  
Subgrid Scale ◽  
Local Scaling ◽  
Stable Boundary Layers ◽  
Stable Boundary ◽  
Boundary Layer Turbulence ◽  
Scaling Hypothesis ◽  
Large Eddy

Abstract A new tuning-free subgrid-scale model, termed locally averaged scale-dependent dynamic (LASDD) model, is developed and implemented in large-eddy simulations (LES) of stable boundary layers. The new model dynamically computes the Smagorinsky coefficient and the subgrid-scale Prandtl number based on the local dynamics of the resolved velocity and temperature fields. Overall, the agreement between the statistics of the LES-generated turbulence and some well-established empirical formulations and theoretical predictions (e.g., the local scaling hypothesis) is remarkable. Moreover, the simulated statistics obtained with the LASDD model show relatively little resolution dependence for the range of grid sizes considered here. In essence, it is shown here that the new LASDD model is a robust subgrid-scale parameterization for reliable, tuning-free simulations of stable boundary layers, even with relatively coarse resolutions.

scholarly journals Local scaling characteristics of Antarctic surface layer turbulence

2010 ◽  
Vol 4 (3) ◽  
pp. 325-331 ◽  
Author(s):  
S. Basu ◽  
A. Ruiz-Columbié ◽  
J. A. Phillipson ◽  
S. Harshan
Keyword(s):  
Surface Layer ◽  
Boundary Layers ◽  
South Pole ◽  
Local Scaling ◽  
Stable Boundary Layers ◽  
Stable Boundary ◽  
The Past ◽  
Scaling Hypothesis ◽  
Turbulence Data ◽  
The Antarctic

Abstract. Over the past years, several studies have validated Nieuwstadt's local scaling hypothesis by utilizing turbulence observations from the mid-latitude, nocturnal stable boundary layers. In this work, we probe into the local scaling characteristics of polar, long-lived stable boundary layers by analyzing turbulence data from the South Pole region of the antarctic plateau.

scholarly journals Local scaling characteristics of Antarctic surface layer turbulence

2010 ◽  
Vol 4 (1) ◽  
pp. 409-427
Author(s):  
S. Basu ◽  
A. Ruiz-Columbié ◽  
J. A. Phillipson ◽  
S. Harshan
Keyword(s):  
Surface Layer ◽  
Boundary Layers ◽  
South Pole ◽  
Local Scaling ◽  
Stable Boundary Layers ◽  
Stable Boundary ◽  
The Past ◽  
Scaling Hypothesis ◽  
Turbulence Data ◽  
The Antarctic

Abstract. Over the past years, several studies have validated Nieuwstadt's local scaling hypothesis by utilizing turbulence observations from the mid-latitude, nocturnal stable boundary layers. In this work, we probe into the local scaling characteristics of polar, long-lived stable boundary layers by analyzing turbulence data from the South Pole region of the Antarctic Plateau.

Large Eddy Simulations of a Hydrocyclone

2002 ◽  
Author(s):  
Francisco Jose´ de Souza ◽  
Aristeu Silveira Neto
Keyword(s):  
Turbulence Models ◽  
Fluid Flows ◽  
Scale Model ◽  
Staggered Grid ◽  
Subgrid Scale ◽  
Step Method ◽  
Fractional Step Method ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Subgrid Scale Modeling

Subgrid-scale modeling, which characterizes Large Eddy Simulation (LES), has been used to predict the behavior of a water-fed hydrocyclone operating without an air core. The governing equations were solved by a fractional step method on a staggered grid. The Smagorinsky subgrid-scale model was employed to account for turbulent effects. Numerical results actually capture the main features of the flow pattern and agree reasonably well with experiments, suggesting that LES represents an interesting alternative to classical turbulence models when applied to the numerical solution of fluid flows within hydrocyclones.

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