CFD Analysis of Urban Canopy Flows Employing the V2F Model: Impact of Different Aspect Ratios and Relative Heights
Computational fluid dynamics (CFD) is currently used in the environmental field to simulate flow and dispersion of pollutants around buildings. However, the closure assumptions of the turbulence usually employed in CFD codes are not always physically based and adequate for all the flow regimes relat...
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| Format: | Article |
| Language: | English |
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Wiley
2018-01-01
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| Series: | Advances in Meteorology |
| Online Access: | http://dx.doi.org/10.1155/2018/2189234 |
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| author | Fabio Nardecchia Annalisa Di Bernardino Francesca Pagliaro Paolo Monti Giovanni Leuzzi Luca Gugliermetti |
| author_facet | Fabio Nardecchia Annalisa Di Bernardino Francesca Pagliaro Paolo Monti Giovanni Leuzzi Luca Gugliermetti |
| author_sort | Fabio Nardecchia |
| collection | DOAJ |
| description | Computational fluid dynamics (CFD) is currently used in the environmental field to simulate flow and dispersion of pollutants around buildings. However, the closure assumptions of the turbulence usually employed in CFD codes are not always physically based and adequate for all the flow regimes relating to practical applications. The starting point of this work is the performance assessment of the V2F (i.e., v2¯ − f) model implemented in Ansys Fluent for simulating the flow field in an idealized array of two-dimensional canyons. The V2F model has been used in the past to predict low-speed and wall-bounded flows, but it has never been used to simulate airflows in urban street canyons. The numerical results are validated against experimental data collected in the water channel and compared with other turbulence models incorporated in Ansys Fluent (i.e., variations of both k-ε and k-ω models and the Reynolds stress model). The results show that the V2F model provides the best prediction of the flow field for two flow regimes commonly found in urban canopies. The V2F model is also employed to quantify the air-exchange rate (ACH) for a series of two-dimensional building arrangements, such as step-up and step-down configurations, having different aspect ratios and relative heights of the buildings. The results show a clear dependence of the ACH on the latter two parameters and highlight the role played by the turbulence in the exchange of air mass, particularly important for the step-down configurations, when the ventilation associated with the mean flow is generally poor. |
| format | Article |
| id | doaj-art-3bd5b116a6e3476fae9e6bf52bfba4cf |
| institution | Kabale University |
| issn | 1687-9309 1687-9317 |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Meteorology |
| spelling | doaj-art-3bd5b116a6e3476fae9e6bf52bfba4cf2025-08-20T03:55:41ZengWileyAdvances in Meteorology1687-93091687-93172018-01-01201810.1155/2018/21892342189234CFD Analysis of Urban Canopy Flows Employing the V2F Model: Impact of Different Aspect Ratios and Relative HeightsFabio Nardecchia0Annalisa Di Bernardino1Francesca Pagliaro2Paolo Monti3Giovanni Leuzzi4Luca Gugliermetti5Sapienza University of Rome, DAEEE, Via Eudossiana 18, Rome 00184, ItalySapienza University of Rome, DICEA, Via Eudossiana 18, Rome 00184, ItalySapienza University of Rome, DAEEE, Via Eudossiana 18, Rome 00184, ItalySapienza University of Rome, DICEA, Via Eudossiana 18, Rome 00184, ItalySapienza University of Rome, DICEA, Via Eudossiana 18, Rome 00184, ItalySapienza University of Rome, DAEEE, Via Eudossiana 18, Rome 00184, ItalyComputational fluid dynamics (CFD) is currently used in the environmental field to simulate flow and dispersion of pollutants around buildings. However, the closure assumptions of the turbulence usually employed in CFD codes are not always physically based and adequate for all the flow regimes relating to practical applications. The starting point of this work is the performance assessment of the V2F (i.e., v2¯ − f) model implemented in Ansys Fluent for simulating the flow field in an idealized array of two-dimensional canyons. The V2F model has been used in the past to predict low-speed and wall-bounded flows, but it has never been used to simulate airflows in urban street canyons. The numerical results are validated against experimental data collected in the water channel and compared with other turbulence models incorporated in Ansys Fluent (i.e., variations of both k-ε and k-ω models and the Reynolds stress model). The results show that the V2F model provides the best prediction of the flow field for two flow regimes commonly found in urban canopies. The V2F model is also employed to quantify the air-exchange rate (ACH) for a series of two-dimensional building arrangements, such as step-up and step-down configurations, having different aspect ratios and relative heights of the buildings. The results show a clear dependence of the ACH on the latter two parameters and highlight the role played by the turbulence in the exchange of air mass, particularly important for the step-down configurations, when the ventilation associated with the mean flow is generally poor.http://dx.doi.org/10.1155/2018/2189234 |
| spellingShingle | Fabio Nardecchia Annalisa Di Bernardino Francesca Pagliaro Paolo Monti Giovanni Leuzzi Luca Gugliermetti CFD Analysis of Urban Canopy Flows Employing the V2F Model: Impact of Different Aspect Ratios and Relative Heights Advances in Meteorology |
| title | CFD Analysis of Urban Canopy Flows Employing the V2F Model: Impact of Different Aspect Ratios and Relative Heights |
| title_full | CFD Analysis of Urban Canopy Flows Employing the V2F Model: Impact of Different Aspect Ratios and Relative Heights |
| title_fullStr | CFD Analysis of Urban Canopy Flows Employing the V2F Model: Impact of Different Aspect Ratios and Relative Heights |
| title_full_unstemmed | CFD Analysis of Urban Canopy Flows Employing the V2F Model: Impact of Different Aspect Ratios and Relative Heights |
| title_short | CFD Analysis of Urban Canopy Flows Employing the V2F Model: Impact of Different Aspect Ratios and Relative Heights |
| title_sort | cfd analysis of urban canopy flows employing the v2f model impact of different aspect ratios and relative heights |
| url | http://dx.doi.org/10.1155/2018/2189234 |
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