Turbulence modelling and turbulent inlet on a blunt plate: a numerical study

Giulio Vita; Hassan Hemida; C Baniotopoulos

Turbulence modelling and turbulent inlet on a blunt plate: a numerical study

Giulio Vita, Hassan Hemida, C Baniotopoulos

Civil Engineering

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

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Abstract

Free Stream Turbulence is usually disregarded as a governing parameter in the assessment of aerodynamic forces. However, an effect is noticeable on the aerodynamic coefficients if turbulence is added at the inlet. In this work, the performance of different sub-grid scale (SGS) models of large-eddy simulation (LES) is investigated against their capability to describe the separation bubble of a blunt plate under a turbulent inlet. This is aimed at starting a broader research on the actual role of turbulence on the aerodynamic behaviour. Together with the Smagorinsky, the dynamic and the WALE SGS models, also the URANS "k-ε" and "k-" ω SST have been compared. The results show that whether URANS is able to accurately describe the undisturbed case, it gives a wrong turbulent inlet in the other one. Although the LES technique can improve the accuracy of this complex configuration, the choice of a suitable averaging time strongly affects the validation of the model. It was found that the role of the SGS eddies is not preponderant. Then a complex system of equations may lead to instability of the solver and prohibitive time step requirements. Among the SGS models investigated, the Smagorinsky SGS model, using a damping function to tackle the near-wall behaviour, qualifies then as a good candidate for further, more complex, geometries

Original language	English
Title of host publication	Proceedings of the XIV Conference of the Italian Association for Wind Engineering - IN-VENTO 2016
Editors	Annibale Luigi Materazzi, Ilaria Venanzi
Publisher	Morlacchi University Press
ISBN (Electronic)	9788860749956
Publication status	Published - 5 May 2018
Event	XIV Conference of the Italian Association for Wind Engineering - Terni, Italy Duration: 25 Sept 2016 → 28 Sept 2016

Conference

Conference	XIV Conference of the Italian Association for Wind Engineering
Abbreviated title	IN-VENTO 2016
Country/Territory	Italy
City	Terni
Period	25/09/16 → 28/09/16

ASJC Scopus subject areas

Renewable Energy, Sustainability and the Environment
Civil and Structural Engineering

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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Giulio_Vita_et_al_Turbulence_modelling_and_turbulent_inlet_on_a_blunt_plate_IN_VENTO_2016
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Cite this

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title = "Turbulence modelling and turbulent inlet on a blunt plate: a numerical study",

abstract = "Free Stream Turbulence is usually disregarded as a governing parameter in the assessment of aerodynamic forces. However, an effect is noticeable on the aerodynamic coefficients if turbulence is added at the inlet. In this work, the performance of different sub-grid scale (SGS) models of large-eddy simulation (LES) is investigated against their capability to describe the separation bubble of a blunt plate under a turbulent inlet. This is aimed at starting a broader research on the actual role of turbulence on the aerodynamic behaviour. Together with the Smagorinsky, the dynamic and the WALE SGS models, also the URANS {"}k-ε{"} and {"}k-{"} ω SST have been compared. The results show that whether URANS is able to accurately describe the undisturbed case, it gives a wrong turbulent inlet in the other one. Although the LES technique can improve the accuracy of this complex configuration, the choice of a suitable averaging time strongly affects the validation of the model. It was found that the role of the SGS eddies is not preponderant. Then a complex system of equations may lead to instability of the solver and prohibitive time step requirements. Among the SGS models investigated, the Smagorinsky SGS model, using a damping function to tackle the near-wall behaviour, qualifies then as a good candidate for further, more complex, geometries",

author = "Giulio Vita and Hassan Hemida and C Baniotopoulos",

year = "2018",

month = may,

day = "5",

language = "English",

editor = "Materazzi, {Annibale Luigi } and Venanzi, {Ilaria }",

booktitle = "Proceedings of the XIV Conference of the Italian Association for Wind Engineering - IN-VENTO 2016",

publisher = "Morlacchi University Press",

address = "Italy",

note = "XIV Conference of the Italian Association for Wind Engineering, IN-VENTO 2016 ; Conference date: 25-09-2016 Through 28-09-2016",

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Vita, G, Hemida, H & Baniotopoulos, C 2018, Turbulence modelling and turbulent inlet on a blunt plate: a numerical study. in AL Materazzi & I Venanzi (eds), Proceedings of the XIV Conference of the Italian Association for Wind Engineering - IN-VENTO 2016. Morlacchi University Press, XIV Conference of the Italian Association for Wind Engineering, Terni, Italy, 25/09/16.

Turbulence modelling and turbulent inlet on a blunt plate: a numerical study. / Vita, Giulio; Hemida, Hassan ; Baniotopoulos, C.
Proceedings of the XIV Conference of the Italian Association for Wind Engineering - IN-VENTO 2016. ed. / Annibale Luigi Materazzi; Ilaria Venanzi. Morlacchi University Press, 2018.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

TY - GEN

T1 - Turbulence modelling and turbulent inlet on a blunt plate

T2 - XIV Conference of the Italian Association for Wind Engineering

AU - Vita, Giulio

AU - Hemida, Hassan

AU - Baniotopoulos, C

PY - 2018/5/5

Y1 - 2018/5/5

N2 - Free Stream Turbulence is usually disregarded as a governing parameter in the assessment of aerodynamic forces. However, an effect is noticeable on the aerodynamic coefficients if turbulence is added at the inlet. In this work, the performance of different sub-grid scale (SGS) models of large-eddy simulation (LES) is investigated against their capability to describe the separation bubble of a blunt plate under a turbulent inlet. This is aimed at starting a broader research on the actual role of turbulence on the aerodynamic behaviour. Together with the Smagorinsky, the dynamic and the WALE SGS models, also the URANS "k-ε" and "k-" ω SST have been compared. The results show that whether URANS is able to accurately describe the undisturbed case, it gives a wrong turbulent inlet in the other one. Although the LES technique can improve the accuracy of this complex configuration, the choice of a suitable averaging time strongly affects the validation of the model. It was found that the role of the SGS eddies is not preponderant. Then a complex system of equations may lead to instability of the solver and prohibitive time step requirements. Among the SGS models investigated, the Smagorinsky SGS model, using a damping function to tackle the near-wall behaviour, qualifies then as a good candidate for further, more complex, geometries

AB - Free Stream Turbulence is usually disregarded as a governing parameter in the assessment of aerodynamic forces. However, an effect is noticeable on the aerodynamic coefficients if turbulence is added at the inlet. In this work, the performance of different sub-grid scale (SGS) models of large-eddy simulation (LES) is investigated against their capability to describe the separation bubble of a blunt plate under a turbulent inlet. This is aimed at starting a broader research on the actual role of turbulence on the aerodynamic behaviour. Together with the Smagorinsky, the dynamic and the WALE SGS models, also the URANS "k-ε" and "k-" ω SST have been compared. The results show that whether URANS is able to accurately describe the undisturbed case, it gives a wrong turbulent inlet in the other one. Although the LES technique can improve the accuracy of this complex configuration, the choice of a suitable averaging time strongly affects the validation of the model. It was found that the role of the SGS eddies is not preponderant. Then a complex system of equations may lead to instability of the solver and prohibitive time step requirements. Among the SGS models investigated, the Smagorinsky SGS model, using a damping function to tackle the near-wall behaviour, qualifies then as a good candidate for further, more complex, geometries

UR - http://hdl.handle.net/11391/1434288

M3 - Conference contribution

BT - Proceedings of the XIV Conference of the Italian Association for Wind Engineering - IN-VENTO 2016

A2 - Materazzi, Annibale Luigi

A2 - Venanzi, Ilaria

PB - Morlacchi University Press

Y2 - 25 September 2016 through 28 September 2016

ER -

Turbulence modelling and turbulent inlet on a blunt plate: a numerical study

Abstract

Conference

ASJC Scopus subject areas

UN SDGs

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