Similarity of the low-occurrence wind profiles within urban turbulent boundary layers of uniform and non-uniform height block arrays
Within urban boundary layers, the safety of pedestrians is markedly affected by wind speed, particularly in urban areas. The characteristics of turbulence above the canopy layers can lead to unpredictable changes in wind speed at the pedestrian level. Therefore, this study analyzes low-occurrence wi...
Published in: | BUILDING AND ENVIRONMENT |
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Main Authors: | , , , |
Format: | Article |
Language: | English |
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PERGAMON-ELSEVIER SCIENCE LTD
2025
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Online Access: | https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001331931000001 |
author |
Zainol Muhd Azhar bin; Wang Wei; Ikegaya Naoki |
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Zainol Muhd Azhar bin; Wang Wei; Ikegaya Naoki Similarity of the low-occurrence wind profiles within urban turbulent boundary layers of uniform and non-uniform height block arrays Construction & Building Technology; Engineering |
author_facet |
Zainol Muhd Azhar bin; Wang Wei; Ikegaya Naoki |
author_sort |
Zainol |
spelling |
Zainol, Muhd Azhar bin; Wang, Wei; Ikegaya, Naoki Similarity of the low-occurrence wind profiles within urban turbulent boundary layers of uniform and non-uniform height block arrays BUILDING AND ENVIRONMENT English Article Within urban boundary layers, the safety of pedestrians is markedly affected by wind speed, particularly in urban areas. The characteristics of turbulence above the canopy layers can lead to unpredictable changes in wind speed at the pedestrian level. Therefore, this study analyzes low-occurrence wind speed phenomena above canopy heights for uniform and nonuniform block configurations using wind tunnel experiments (WTE) to understand the background turbulence characteristics which the wind profile is generated by the boundary layer above the canopy. The urban canopy arrays were reproduced using solid blocks arranged in 30 rows in a streamwise direction with a packing density of 25 % at three different heights. An x-type hot-wire anemometer was used to measure the streamwise and vertical velocity components. The low-occurrence values were classified based on wind speed percentiles of 0.1 %, 1.0%, 99.0%, and 99.9% wind speeds. The results demonstrated that above the canopy, there were minor influences of block height variations on the low occurrence factor. The peak factor demonstrated a comparable value between the uniform and nonuniform cases, regardless of the block arrangement. Statistical models based on the Weibull distribution and Gram-Charlier series demonstrating good agreement with the WTE data in predicting the low occurrence and peak factors. This study found that variations in block height have a minor influence on the low occurrence and peak factors within the turbulent boundary layers, implying that we can separate the effect of background turbulence from the local turbulent generation within the urban canopy layers. PERGAMON-ELSEVIER SCIENCE LTD 0360-1323 1873-684X 2025 267 10.1016/j.buildenv.2024.112138 Construction & Building Technology; Engineering WOS:001331931000001 https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001331931000001 |
title |
Similarity of the low-occurrence wind profiles within urban turbulent boundary layers of uniform and non-uniform height block arrays |
title_short |
Similarity of the low-occurrence wind profiles within urban turbulent boundary layers of uniform and non-uniform height block arrays |
title_full |
Similarity of the low-occurrence wind profiles within urban turbulent boundary layers of uniform and non-uniform height block arrays |
title_fullStr |
Similarity of the low-occurrence wind profiles within urban turbulent boundary layers of uniform and non-uniform height block arrays |
title_full_unstemmed |
Similarity of the low-occurrence wind profiles within urban turbulent boundary layers of uniform and non-uniform height block arrays |
title_sort |
Similarity of the low-occurrence wind profiles within urban turbulent boundary layers of uniform and non-uniform height block arrays |
container_title |
BUILDING AND ENVIRONMENT |
language |
English |
format |
Article |
description |
Within urban boundary layers, the safety of pedestrians is markedly affected by wind speed, particularly in urban areas. The characteristics of turbulence above the canopy layers can lead to unpredictable changes in wind speed at the pedestrian level. Therefore, this study analyzes low-occurrence wind speed phenomena above canopy heights for uniform and nonuniform block configurations using wind tunnel experiments (WTE) to understand the background turbulence characteristics which the wind profile is generated by the boundary layer above the canopy. The urban canopy arrays were reproduced using solid blocks arranged in 30 rows in a streamwise direction with a packing density of 25 % at three different heights. An x-type hot-wire anemometer was used to measure the streamwise and vertical velocity components. The low-occurrence values were classified based on wind speed percentiles of 0.1 %, 1.0%, 99.0%, and 99.9% wind speeds. The results demonstrated that above the canopy, there were minor influences of block height variations on the low occurrence factor. The peak factor demonstrated a comparable value between the uniform and nonuniform cases, regardless of the block arrangement. Statistical models based on the Weibull distribution and Gram-Charlier series demonstrating good agreement with the WTE data in predicting the low occurrence and peak factors. This study found that variations in block height have a minor influence on the low occurrence and peak factors within the turbulent boundary layers, implying that we can separate the effect of background turbulence from the local turbulent generation within the urban canopy layers. |
publisher |
PERGAMON-ELSEVIER SCIENCE LTD |
issn |
0360-1323 1873-684X |
publishDate |
2025 |
container_volume |
267 |
container_issue |
|
doi_str_mv |
10.1016/j.buildenv.2024.112138 |
topic |
Construction & Building Technology; Engineering |
topic_facet |
Construction & Building Technology; Engineering |
accesstype |
|
id |
WOS:001331931000001 |
url |
https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001331931000001 |
record_format |
wos |
collection |
Web of Science (WoS) |
_version_ |
1814778544268509184 |