Validation of Simplified Urban-Canopy Aerodynamic Parametrizations Using a Numerical Simulation of an Actual Downtown Area
Abstract A steady-state Reynolds-averaged Navier–Stoke computational fluid dynamics (CFD) investigation of boundary-layer flow over a major portion of downtown Abu Dhabi is conducted. The results are used to derive the shear stress and characterize the logarithmic region for eight sub...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Springer Netherlands
2021
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| Online Access: | https://hdl.handle.net/1721.1/131745 |
| _version_ | 1826210956211912704 |
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| author | Ramirez, N. Afshari, Afshin Norford, L. |
| author_facet | Ramirez, N. Afshari, Afshin Norford, L. |
| author_sort | Ramirez, N. |
| collection | MIT |
| description | Abstract
A steady-state Reynolds-averaged Navier–Stoke computational fluid dynamics (CFD) investigation of boundary-layer flow over a major portion of downtown Abu Dhabi is conducted. The results are used to derive the shear stress and characterize the logarithmic region for eight sub-domains, where the sub-domains overlap and are overlaid in the streamwise direction. They are characterized by a high frontal area index initially, which decreases significantly beyond the fifth sub-domain. The plan area index is relatively stable throughout the domain. For each sub-domain, the estimated local roughness length and displacement height derived from CFD results are compared to prevalent empirical formulations. We further validate and tune a mixing-length model proposed by Coceal and Belcher (Q J R Meteorol Soc 130:1349–1372, 2004). Finally, the in-canopy wind-speed attenuation is analysed as a function of fetch. It is shown that, while there is some room for improvement in Macdonald’s empirical formulations (Boundary-Layer Meteorol 97:25–45, 2000), Coceal and Belcher’s mixing model in combination with the resolution method of Di Sabatino et al. (Boundary-Layer Meteorol 127:131–151, 2008) can provide a robust estimation of the average wind speed in the logarithmic region. Within the roughness sublayer, a properly parametrized Cionco exponential model is shown to be quite accurate. |
| first_indexed | 2024-09-23T14:58:27Z |
| format | Article |
| id | mit-1721.1/131745 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T14:58:27Z |
| publishDate | 2021 |
| publisher | Springer Netherlands |
| record_format | dspace |
| spelling | mit-1721.1/1317452021-09-21T03:15:56Z Validation of Simplified Urban-Canopy Aerodynamic Parametrizations Using a Numerical Simulation of an Actual Downtown Area Ramirez, N. Afshari, Afshin Norford, L. Abstract A steady-state Reynolds-averaged Navier–Stoke computational fluid dynamics (CFD) investigation of boundary-layer flow over a major portion of downtown Abu Dhabi is conducted. The results are used to derive the shear stress and characterize the logarithmic region for eight sub-domains, where the sub-domains overlap and are overlaid in the streamwise direction. They are characterized by a high frontal area index initially, which decreases significantly beyond the fifth sub-domain. The plan area index is relatively stable throughout the domain. For each sub-domain, the estimated local roughness length and displacement height derived from CFD results are compared to prevalent empirical formulations. We further validate and tune a mixing-length model proposed by Coceal and Belcher (Q J R Meteorol Soc 130:1349–1372, 2004). Finally, the in-canopy wind-speed attenuation is analysed as a function of fetch. It is shown that, while there is some room for improvement in Macdonald’s empirical formulations (Boundary-Layer Meteorol 97:25–45, 2000), Coceal and Belcher’s mixing model in combination with the resolution method of Di Sabatino et al. (Boundary-Layer Meteorol 127:131–151, 2008) can provide a robust estimation of the average wind speed in the logarithmic region. Within the roughness sublayer, a properly parametrized Cionco exponential model is shown to be quite accurate. 2021-09-20T17:30:06Z 2021-09-20T17:30:06Z 2018-02-27 2020-09-24T20:33:02Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/131745 en https://doi.org/10.1007/s10546-018-0345-7 Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ Springer Science+Business Media B.V., part of Springer Nature application/pdf Springer Netherlands Springer Netherlands |
| spellingShingle | Ramirez, N. Afshari, Afshin Norford, L. Validation of Simplified Urban-Canopy Aerodynamic Parametrizations Using a Numerical Simulation of an Actual Downtown Area |
| title | Validation of Simplified Urban-Canopy Aerodynamic Parametrizations Using a Numerical Simulation of an Actual Downtown Area |
| title_full | Validation of Simplified Urban-Canopy Aerodynamic Parametrizations Using a Numerical Simulation of an Actual Downtown Area |
| title_fullStr | Validation of Simplified Urban-Canopy Aerodynamic Parametrizations Using a Numerical Simulation of an Actual Downtown Area |
| title_full_unstemmed | Validation of Simplified Urban-Canopy Aerodynamic Parametrizations Using a Numerical Simulation of an Actual Downtown Area |
| title_short | Validation of Simplified Urban-Canopy Aerodynamic Parametrizations Using a Numerical Simulation of an Actual Downtown Area |
| title_sort | validation of simplified urban canopy aerodynamic parametrizations using a numerical simulation of an actual downtown area |
| url | https://hdl.handle.net/1721.1/131745 |
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