Impact of inflow methods and aerodynamic roughness lengths on the streamwise homogeneity of flow profiles in LES of the neutral ABL

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

Abstract

In Computational Fluid Dynamics (CFD) simulations of the atmospheric boundary layer (ABL) the relation between inflow conditions and wall boundary conditions has been thoroughly investigated for Reynolds-averaged Navier-Stokes (RANS) modeling, whereas it yet needs to be evaluated for Large Eddy Simulations (LES). In the present paper streamwise homogeneity of flow profiles for LES of the neutral ABL over surfaces with different aerodynamic roughness lengths in combination with three different inflow turbulence generation methods is investigated. Specifically, one precursor and two synthetic methods have been considered along with three aerodynamic roughness lengths. The results show that the precursor method satisfactorily preserves the homogeneity of both mean velocity and turbulence kinetic energy, with respective average deviations up to 0.7% and 3.5% from target profiles at the outlet of the domain. Among the synthetic methods, less accurate but also less computationally demanding than the precursor method, the Vortex Method greatly outperforms the Spectral Synthesizer in terms of both mean velocity and turbulence kinetic energy. Lastly, terrain roughness is found to have only a weak influence on the performance of the inflow methods considered.
Original languageEnglish
Title of host publicationXIV Conference of the Italian Association for Wind Engineering (IN-VENTO 2016), 25-28 September 2016, Terni, Italy
Number of pages10
Publication statusPublished - 2016
Event14th Conference of the Italian Association for Wind Engineering (IN-VENTO 2016) - Hotel Valentino, Terni, Italy
Duration: 25 Sep 201628 Sep 2016
Conference number: 14
http://www.in-vento-2016.org/
http://www.in-vento-2016.org/

Conference

Conference14th Conference of the Italian Association for Wind Engineering (IN-VENTO 2016)
Abbreviated titleIN-VENTO 2016
CountryItaly
CityTerni
Period25/09/1628/09/16
Internet address

Fingerprint

Atmospheric boundary layer
Large eddy simulation
Aerodynamics
Turbulence
Surface roughness
Kinetic energy
Computational fluid dynamics
Vortex flow
Boundary conditions
Computer simulation

Cite this

Vasaturo, R., Kalkman, I. M., Blocken, B., & van Wesemael, P. J. V. (2016). Impact of inflow methods and aerodynamic roughness lengths on the streamwise homogeneity of flow profiles in LES of the neutral ABL. In XIV Conference of the Italian Association for Wind Engineering (IN-VENTO 2016), 25-28 September 2016, Terni, Italy
Vasaturo, R. ; Kalkman, I.M. ; Blocken, B. ; van Wesemael, P.J.V. / Impact of inflow methods and aerodynamic roughness lengths on the streamwise homogeneity of flow profiles in LES of the neutral ABL. XIV Conference of the Italian Association for Wind Engineering (IN-VENTO 2016), 25-28 September 2016, Terni, Italy. 2016.
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title = "Impact of inflow methods and aerodynamic roughness lengths on the streamwise homogeneity of flow profiles in LES of the neutral ABL",
abstract = "In Computational Fluid Dynamics (CFD) simulations of the atmospheric boundary layer (ABL) the relation between inflow conditions and wall boundary conditions has been thoroughly investigated for Reynolds-averaged Navier-Stokes (RANS) modeling, whereas it yet needs to be evaluated for Large Eddy Simulations (LES). In the present paper streamwise homogeneity of flow profiles for LES of the neutral ABL over surfaces with different aerodynamic roughness lengths in combination with three different inflow turbulence generation methods is investigated. Specifically, one precursor and two synthetic methods have been considered along with three aerodynamic roughness lengths. The results show that the precursor method satisfactorily preserves the homogeneity of both mean velocity and turbulence kinetic energy, with respective average deviations up to 0.7{\%} and 3.5{\%} from target profiles at the outlet of the domain. Among the synthetic methods, less accurate but also less computationally demanding than the precursor method, the Vortex Method greatly outperforms the Spectral Synthesizer in terms of both mean velocity and turbulence kinetic energy. Lastly, terrain roughness is found to have only a weak influence on the performance of the inflow methods considered.",
author = "R. Vasaturo and I.M. Kalkman and B. Blocken and {van Wesemael}, P.J.V.",
year = "2016",
language = "English",
booktitle = "XIV Conference of the Italian Association for Wind Engineering (IN-VENTO 2016), 25-28 September 2016, Terni, Italy",

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Vasaturo, R, Kalkman, IM, Blocken, B & van Wesemael, PJV 2016, Impact of inflow methods and aerodynamic roughness lengths on the streamwise homogeneity of flow profiles in LES of the neutral ABL. in XIV Conference of the Italian Association for Wind Engineering (IN-VENTO 2016), 25-28 September 2016, Terni, Italy. 14th Conference of the Italian Association for Wind Engineering (IN-VENTO 2016), Terni, Italy, 25/09/16.

Impact of inflow methods and aerodynamic roughness lengths on the streamwise homogeneity of flow profiles in LES of the neutral ABL. / Vasaturo, R.; Kalkman, I.M.; Blocken, B.; van Wesemael, P.J.V.

XIV Conference of the Italian Association for Wind Engineering (IN-VENTO 2016), 25-28 September 2016, Terni, Italy. 2016.

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

TY - GEN

T1 - Impact of inflow methods and aerodynamic roughness lengths on the streamwise homogeneity of flow profiles in LES of the neutral ABL

AU - Vasaturo, R.

AU - Kalkman, I.M.

AU - Blocken, B.

AU - van Wesemael, P.J.V.

PY - 2016

Y1 - 2016

N2 - In Computational Fluid Dynamics (CFD) simulations of the atmospheric boundary layer (ABL) the relation between inflow conditions and wall boundary conditions has been thoroughly investigated for Reynolds-averaged Navier-Stokes (RANS) modeling, whereas it yet needs to be evaluated for Large Eddy Simulations (LES). In the present paper streamwise homogeneity of flow profiles for LES of the neutral ABL over surfaces with different aerodynamic roughness lengths in combination with three different inflow turbulence generation methods is investigated. Specifically, one precursor and two synthetic methods have been considered along with three aerodynamic roughness lengths. The results show that the precursor method satisfactorily preserves the homogeneity of both mean velocity and turbulence kinetic energy, with respective average deviations up to 0.7% and 3.5% from target profiles at the outlet of the domain. Among the synthetic methods, less accurate but also less computationally demanding than the precursor method, the Vortex Method greatly outperforms the Spectral Synthesizer in terms of both mean velocity and turbulence kinetic energy. Lastly, terrain roughness is found to have only a weak influence on the performance of the inflow methods considered.

AB - In Computational Fluid Dynamics (CFD) simulations of the atmospheric boundary layer (ABL) the relation between inflow conditions and wall boundary conditions has been thoroughly investigated for Reynolds-averaged Navier-Stokes (RANS) modeling, whereas it yet needs to be evaluated for Large Eddy Simulations (LES). In the present paper streamwise homogeneity of flow profiles for LES of the neutral ABL over surfaces with different aerodynamic roughness lengths in combination with three different inflow turbulence generation methods is investigated. Specifically, one precursor and two synthetic methods have been considered along with three aerodynamic roughness lengths. The results show that the precursor method satisfactorily preserves the homogeneity of both mean velocity and turbulence kinetic energy, with respective average deviations up to 0.7% and 3.5% from target profiles at the outlet of the domain. Among the synthetic methods, less accurate but also less computationally demanding than the precursor method, the Vortex Method greatly outperforms the Spectral Synthesizer in terms of both mean velocity and turbulence kinetic energy. Lastly, terrain roughness is found to have only a weak influence on the performance of the inflow methods considered.

M3 - Conference contribution

BT - XIV Conference of the Italian Association for Wind Engineering (IN-VENTO 2016), 25-28 September 2016, Terni, Italy

ER -

Vasaturo R, Kalkman IM, Blocken B, van Wesemael PJV. Impact of inflow methods and aerodynamic roughness lengths on the streamwise homogeneity of flow profiles in LES of the neutral ABL. In XIV Conference of the Italian Association for Wind Engineering (IN-VENTO 2016), 25-28 September 2016, Terni, Italy. 2016