Turbulence Closures In Neutral Boundary Layer Over Complex Terrain

Castelli, Silvia; Ferrero, E.; Anfossi, D.

doi:10.1023/a:1019208518127

Cited by 33 publications

(19 citation statements)

References 14 publications

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“…The model was modified to use the k-ε closure scheme (Trini Castelli et al, 2001) with appropriate initial and lateral boundary conditions described in Section 2.4.2. The CFD code that was used is the same as in Chaviaropoulos et al (1998) with no other modifications except the domain configuration to be the same as in RAMS.…”

Section: Major Difference Between the Two Modelsmentioning

confidence: 99%

“…This closure scheme cannot be used when the terrain variability requires small horizontal grids to explicitly resolve the wind flow pattern. Also, this turbulent closure fails in solving Turbulent Kinetic Energy (TKE) even in gentle slope cases (Trini Castelli et al, 2001). If small scale turbulent motions require being accurately computed, methods estimating the Reynolds stress tensor with the isotropic assumption are necessary.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An intercomparison study between RAMS and CRES-Flow-NS models and evaluation with wind tunnel experimental data: Toward improving atmospheric modeling for wind resource assessment

Barranger

Ternisien

Kallos

2015

Journal of Wind Engineering and Industrial Aerodynamics

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Section: Major Difference Between the Two Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An intercomparison study between RAMS and CRES-Flow-NS models and evaluation with wind tunnel experimental data: Toward improving atmospheric modeling for wind resource assessment

Barranger

Ternisien

Kallos

2015

Journal of Wind Engineering and Industrial Aerodynamics

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“…In studying the flow around buildings, two-equation models, like k-e or k-ω closures, being k the turbulent kinetic energy and ω the vorticity, are generally applied. A standard version of the k-e turbulence closure and the renormalization group (RNG) k-e turbulence model were implemented and tested in RAMS, giving origin to the RAMS6.0-mod [Trini Castelli et al, 2001Ferrero et al, 2003;Reisin et al, 2007;Trini Castelli and Reisin, 2010]. Both closures solve the dynamical equations for the turbulent kinetic energy, k, and its dissipation term, e. With respect to the standard k-e model, the RNG-k-e turbulence scheme [Yakhot et al, 1992] includes also an additional sink term in the turbulence dissipation equation to account for nonequilibrium strain rates and employs different values for the closure coefficients [Trini Castelli and Reisin, 2010].…”

Section: Turbulence and Flow Fieldsmentioning

confidence: 99%

Review and Validation of MicroSpray, a Lagrangian Particle Model of Turbulent Dispersion

Tinarelli¹,

Mortarini

Castelli

et al. 2013

Lagrangian Modeling of the Atmosphere

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In this paper, the MicroSpray 3-D Lagrangian particle dispersion model is presented and reviewed, and several validation studies are shown. Starting from its core, based on a 3-D form of the Langevin equation for the random velocity, the successive developments of different modules treating the main physical processes that determine the atmospheric pollutant dispersion are illustrated. Different probability density functions are implemented to estimate the deterministic coefficient in the Langevin equation. Buoyancy effects are described through simplified plume rise formulations up to a complete set of equations for negatively and positively buoyant emissions, also including phase changes. MicroSpray is able to simulate different types of sources and emissions; it includes the treatment of obstacles and complex orography and offers several options to optimize the numerical runs. The model can be driven both by diagnostic and prognostic atmospheric models, and it has been used and validated in a variety of cases, from experimental to real conditions. Some significant examples of MicroSpray simulations are detailed and discussed.

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“…In the frame of urban environment simulations, two-equations turbulence models of the k-ε kind are commonly used [18,29], where the variable k represents the turbulent kinetic energy and ε its dissipation term. In recent years, a standard version of the k − ε turbulence closure model was implemented and tested in RAMS [5,[23][24][25]. This scheme, even though widely used, has shown some deficiencies when applied to the simulation of flow impingement and separation [1].…”

Section: The Modified Numerical Modelmentioning

confidence: 99%

Evaluation of the atmospheric RAMS model in an obstacle resolving configuration

Castelli

Reisin

2010

Environ Fluid Mech

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The Regional Atmospheric Modelling System (RAMS) was modified and configured to simulate the flow around a rectangular building, corresponding to Case A1-1 in the CEDVAL Project. This experiment was designed to provide a comprehensive compilation of wind tunnel datasets that can be used for validation of numerical flow and dispersion models. A Cartesian grid implemented in the RAMS model permitted the explicit description of the obstacle. The model grid resolution was of the order of 1 m, high enough to resolve the most significant flow characteristics. Two turbulence closures largely used at these scales, k − ε and Renormalization Group k − ε, were implemented in RAMS, tested and evaluated. Some preliminary tests were performed to investigate the effect of the boundary conditions on the flow behaviour at the obstacle walls. A simplified approach, assuming that the wind changes logarithmically in the ambient atmosphere near the building's faces was implemented. Model results show that RAMS successfully reproduces the main flow characteristics. The performances of the different turbulence closures are discussed through a comparison with the observed data and a statistical analysis. A good agreement was obtained for the horizontal and vertical velocities, while the results for the turbulent kinetic energy are generally less satisfactory, especially above the obstacle's height.

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Turbulence Closures In Neutral Boundary Layer Over Complex Terrain

Cited by 33 publications

References 14 publications

An intercomparison study between RAMS and CRES-Flow-NS models and evaluation with wind tunnel experimental data: Toward improving atmospheric modeling for wind resource assessment

An intercomparison study between RAMS and CRES-Flow-NS models and evaluation with wind tunnel experimental data: Toward improving atmospheric modeling for wind resource assessment

Review and Validation of MicroSpray, a Lagrangian Particle Model of Turbulent Dispersion

Evaluation of the atmospheric RAMS model in an obstacle resolving configuration

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