Explicit algebraic scalar flux approximation

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 985-989
Author(s):  
Y. Shabany ◽  
P. A. Durbin
Keyword(s):  
Scalar Flux ◽  
Flux Approximation

Explicit Algebraic Scalar Flux Approximation

AIAA Journal ◽  
10.2514/2.207 ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 985-989 ◽  
Author(s):  
Y. Shabany ◽  
P. A. Durbin
Keyword(s):  
Scalar Flux ◽  
Flux Approximation

Turbulent three-dimensional dielectric electrohydrodynamic convection between two plates

2012 ◽  
Vol 696 ◽  
pp. 228-262 ◽  
Author(s):  
A. Kourmatzis ◽  
J. S. Shrimpton
Keyword(s):  
Spatial Data ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Energy Budgets ◽  
Turbulent Regime ◽  
Scalar Flux ◽  
Wide Range ◽  
Scalar Variance

AbstractThe fundamental mechanisms responsible for the creation of electrohydrodynamically driven roll structures in free electroconvection between two plates are analysed with reference to traditional Rayleigh–Bénard convection (RBC). Previously available knowledge limited to two dimensions is extended to three-dimensions, and a wide range of electric Reynolds numbers is analysed, extending into a fully inherently three-dimensional turbulent regime. Results reveal that structures appearing in three-dimensional electrohydrodynamics (EHD) are similar to those observed for RBC, and while two-dimensional EHD results bear some similarities with the three-dimensional results there are distinct differences. Analysis of two-point correlations and integral length scales show that full three-dimensional electroconvection is more chaotic than in two dimensions and this is also noted by qualitatively observing the roll structures that arise for both low (${\mathit{Re}}_{E} = 1$) and high electric Reynolds numbers (up to ${\mathit{Re}}_{E} = 120$). Furthermore, calculations of mean profiles and second-order moments along with energy budgets and spectra have examined the validity of neglecting the fluctuating electric field ${ E}_{i}^{\ensuremath{\prime} } $ in the Reynolds-averaged EHD equations and provide insight into the generation and transport mechanisms of turbulent EHD. Spectral and spatial data clearly indicate how fluctuating energy is transferred from electrical to hydrodynamic forms, on moving through the domain away from the charging electrode. It is shown that ${ E}_{i}^{\ensuremath{\prime} } $ is not negligible close to the walls and terms acting as sources and sinks in the turbulent kinetic energy, turbulent scalar flux and turbulent scalar variance equations are examined. Profiles of hydrodynamic terms in the budgets resemble those in the literature for RBC; however there are terms specific to EHD that are significant, indicating that the transfer of energy in EHD is also attributed to further electrodynamic terms and a strong coupling exists between the charge flux and variance, due to the ionic drift term.

Geometrical interpretation of the multi-point flux approximation L-method

2009 ◽  
Vol 60 (11) ◽  
pp. 1173-1199 ◽  
Author(s):  
Yufei Cao ◽  
Rainer Helmig ◽  
Barbara I. Wohlmuth
Keyword(s):  
Geometrical Interpretation ◽  
Flux Approximation

Large Wind Farms and the Scalar Flux over an Heterogeneously Rough Land Surface

2014 ◽  
Vol 153 (3) ◽  
pp. 471-495 ◽  
Author(s):  
Marc Calaf ◽  
Chad Higgins ◽  
Marc B. Parlange
Keyword(s):  
Land Surface ◽  
Wind Farms ◽  
Scalar Flux ◽  
Large Wind

scholarly journals Scalar flux profile relationships over the open ocean

2004 ◽  
Vol 109 (C8) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. B. Edson ◽  
C. J. Zappa ◽  
J. A. Ware ◽  
W. R. McGillis ◽  
J. E. Hare
Keyword(s):  
Open Ocean ◽  
Scalar Flux ◽  
Flux Profile

scholarly journals Spectral modelling for passive scalar dynamics in homogeneous anisotropic turbulence

2016 ◽  
Vol 799 ◽  
pp. 159-199 ◽  
Author(s):  
A. Briard ◽  
T. Gomez ◽  
C. Cambon
Keyword(s):  
Isotropic Turbulence ◽  
Reynolds Numbers ◽  
Passive Scalar ◽  
Homogeneous Isotropic Turbulence ◽  
Scalar Flux ◽  
Anisotropic Turbulence ◽  
Theoretical Predictions ◽  
High Reynolds ◽  
Shear Driven Flows ◽  
Very High

The present work aims at developing a spectral model for a passive scalar field and its associated scalar flux in homogeneous anisotropic turbulence. This is achieved using the paradigm of eddy-damped quasi-normal Markovian (EDQNM) closure extended to anisotropic flows. In order to assess the validity of this approach, the model is compared to several detailed direct numerical simulations (DNS) and experiments of shear-driven flows and isotropic turbulence with a mean scalar gradient at moderate Reynolds numbers. This anisotropic modelling is then used to investigate the passive scalar dynamics at very high Reynolds numbers. In the framework of homogeneous isotropic turbulence submitted to a mean scalar gradient, decay and growth exponents for the cospectrum and scalar energies are obtained analytically and assessed numerically thanks to EDQNM closure. With the additional presence of a mean shear, the scaling of the scalar flux and passive scalar spectra in the inertial range are investigated and confirm recent theoretical predictions. Finally, it is found that, in shear-driven flows, the small scales of the scalar second-order moments progressively return to isotropy when the Reynolds number increases.

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