Numerical Simulations of Boundary-Layer Airflow Over Pitched-Roof Buildings
Numerical Simulations of Boundary-Layer Airflow Over Pitched-Roof Buildings
Arrays of buildings with pitched roofs are common in urban and suburban areas of European cities. Large-eddy simulations are performed to predict the boundary-layer flows over flat and pitched-roof cuboids to gain a greater understanding of the impact of pitched roofs on urban boundary layers. The simulation methodology is validated for an array of flat roof cuboids. Further simulations show that changes in the type of grid conformity have a negligible effect on the mean flow field and turbulent stresses, while having a visible, but small, effect on the dispersive stresses for a given packing density. Comparisons are made for flat and 45
∘ pitched roof cuboid arrays at packing densities of 16.7% and 33.3%. The interactions between pitched-roof buildings and their effect on the urban boundary layer are considerably different to those of flat-roof buildings. The pitched roofs at a packing density of 33.3% leads to significant changes in the mean flow field, the Reynolds stresses, and the aerodynamic drag. Further work investigates the effects of changes in turbulence level and atmospheric thermal stratification in the approaching flow. Importantly, in comparison to a flat-roof array, the pitched-roof one at a packing density of 33.3% evidently increase the friction velocity and greatly reduces the effects of stable stratification conditions and changes in inflow turbulence level.
Atmospheric thermal stratification, Cartesian mesh, Drag coefficient, Packing density, Pitched roof, Spatial-average
415-442
Coburn, Matthew
0ee79550-a5f4-470c-a8eb-5354ee9369c8
Xie, Zheng-Tong
98ced75d-5617-4c2d-b20f-7038c54f4ff0
Herring, Steven
15f891b4-1a9e-4ac8-af74-ce4158274451
December 2022
Coburn, Matthew
0ee79550-a5f4-470c-a8eb-5354ee9369c8
Xie, Zheng-Tong
98ced75d-5617-4c2d-b20f-7038c54f4ff0
Herring, Steven
15f891b4-1a9e-4ac8-af74-ce4158274451
Coburn, Matthew, Xie, Zheng-Tong and Herring, Steven
(2022)
Numerical Simulations of Boundary-Layer Airflow Over Pitched-Roof Buildings.
Boundary-Layer Meteorology, 185 (3), .
(doi:10.1007/s10546-022-00738-1).
Abstract
Arrays of buildings with pitched roofs are common in urban and suburban areas of European cities. Large-eddy simulations are performed to predict the boundary-layer flows over flat and pitched-roof cuboids to gain a greater understanding of the impact of pitched roofs on urban boundary layers. The simulation methodology is validated for an array of flat roof cuboids. Further simulations show that changes in the type of grid conformity have a negligible effect on the mean flow field and turbulent stresses, while having a visible, but small, effect on the dispersive stresses for a given packing density. Comparisons are made for flat and 45
∘ pitched roof cuboid arrays at packing densities of 16.7% and 33.3%. The interactions between pitched-roof buildings and their effect on the urban boundary layer are considerably different to those of flat-roof buildings. The pitched roofs at a packing density of 33.3% leads to significant changes in the mean flow field, the Reynolds stresses, and the aerodynamic drag. Further work investigates the effects of changes in turbulence level and atmospheric thermal stratification in the approaching flow. Importantly, in comparison to a flat-roof array, the pitched-roof one at a packing density of 33.3% evidently increase the friction velocity and greatly reduces the effects of stable stratification conditions and changes in inflow turbulence level.
Text
BLM2021_Pitched_Roof_15_nov
- Accepted Manuscript
Text
s10546-022-00738-1
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More information
Submitted date: 15 November 2021
Accepted/In Press date: 26 July 2022
e-pub ahead of print date: 23 August 2022
Published date: December 2022
Additional Information:
Funding Information:
This research is mainly funded by a studentship of the Faculty of Engineering and the Environment. MC thanks Dr Tim Foat from the Defence Science and Technology Laboratory (Dstl) for providing insight and support. The authors thank the three anonymous peer reviewers for their very valuable comments and suggestions. Computational work has been undertaken on Southampton University’s Iridis systems. The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
Funding Information:
This research is mainly funded by a studentship of the Faculty of Engineering and the Environment. MC thanks Dr Tim Foat from the Defence Science and Technology Laboratory (Dstl) for providing insight and support. The authors thank the three anonymous peer reviewers for their very valuable comments and suggestions. Computational work has been undertaken on Southampton University’s Iridis systems. The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
Publisher Copyright:
© 2022, The Author(s).
Keywords:
Atmospheric thermal stratification, Cartesian mesh, Drag coefficient, Packing density, Pitched roof, Spatial-average
Identifiers
Local EPrints ID: 452766
URI: http://eprints.soton.ac.uk/id/eprint/452766
ISSN: 0006-8314
PURE UUID: 2f0cb0ae-cf09-4965-a830-e5e1c62b8a6d
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Date deposited: 20 Dec 2021 17:32
Last modified: 14 Jun 2024 04:01
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Author:
Matthew Coburn
Author:
Steven Herring
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