LES case study on pedestrian level ventilation in two neighbourhoods in Hong Kong
Hong Kong is one of the most densely built-up and populated cities in the world. An adequate air ventilation at pedestrian level would ease the thermal stress in its humid subtropical climate, but the high-density city severely reduces the natural ventilation. This case study investigates pedestrian...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Borntraeger
2012-12-01
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| Series: | Meteorologische Zeitschrift |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1127/0941-2948/2012/0356 |
| _version_ | 1797332691195002880 |
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| author | Marcus Oliver Letzel Carolin Helmke Edward Ng Xipo An Alan Lai Siegfried Raasch |
| author_facet | Marcus Oliver Letzel Carolin Helmke Edward Ng Xipo An Alan Lai Siegfried Raasch |
| author_sort | Marcus Oliver Letzel |
| collection | DOAJ |
| description | Hong Kong is one of the most densely built-up and populated cities in the world. An adequate air ventilation at pedestrian level would ease the thermal stress in its humid subtropical climate, but the high-density city severely reduces the natural ventilation. This case study investigates pedestrian level ventilation in two neighbourhoods in Kowloon, downtown Hong Kong using the parallelized large-eddy-simulation (LES) model PALM. The LES technique is chosen here for a city quarter scale pedestrian comfort study despite of its high computational cost. The aims of the paper are a) to get a comprehensive overview of pedestrian level ventilation and a better understanding of the ventilation processes in downtown Hong Kong, b) to test the LES technique on this urban scale compared to the wind tunnel and c) to investigate how numerical/physical parameters influence ventilation. This case study is restricted to neutral stratification in order to allow a direct comparison with the wind tunnel. A sensitivity study quantifies the dependence of site-averaged ventilation on numerical and physical parameters and determines an appropriate urban LES set-up for two 1 km2 neighbourhoods in Kowloon (Tsim Sha Tsui, Mong Kok) that are investigated for prevailing E and SW wind. The results reveal the critical dependence of ventilation on the urban morphology. Air paths, street orientations, ground coverage, sites fronting the water, inter connectivity of spaces, building podium size and building heights can all affect the pedestrian wind environment. Isolated tall buildings may have a pronounced impact on ventilation both locally and downstream. |
| first_indexed | 2024-03-08T07:52:35Z |
| format | Article |
| id | doaj.art-34379cd795a448aeab3087b091552eed |
| institution | Directory Open Access Journal |
| issn | 0941-2948 |
| language | English |
| last_indexed | 2024-03-08T07:52:35Z |
| publishDate | 2012-12-01 |
| publisher | Borntraeger |
| record_format | Article |
| series | Meteorologische Zeitschrift |
| spelling | doaj.art-34379cd795a448aeab3087b091552eed2024-02-02T14:34:36ZengBorntraegerMeteorologische Zeitschrift0941-29482012-12-0121657558910.1127/0941-2948/2012/035679530LES case study on pedestrian level ventilation in two neighbourhoods in Hong KongMarcus Oliver LetzelCarolin HelmkeEdward NgXipo AnAlan LaiSiegfried RaaschHong Kong is one of the most densely built-up and populated cities in the world. An adequate air ventilation at pedestrian level would ease the thermal stress in its humid subtropical climate, but the high-density city severely reduces the natural ventilation. This case study investigates pedestrian level ventilation in two neighbourhoods in Kowloon, downtown Hong Kong using the parallelized large-eddy-simulation (LES) model PALM. The LES technique is chosen here for a city quarter scale pedestrian comfort study despite of its high computational cost. The aims of the paper are a) to get a comprehensive overview of pedestrian level ventilation and a better understanding of the ventilation processes in downtown Hong Kong, b) to test the LES technique on this urban scale compared to the wind tunnel and c) to investigate how numerical/physical parameters influence ventilation. This case study is restricted to neutral stratification in order to allow a direct comparison with the wind tunnel. A sensitivity study quantifies the dependence of site-averaged ventilation on numerical and physical parameters and determines an appropriate urban LES set-up for two 1 km2 neighbourhoods in Kowloon (Tsim Sha Tsui, Mong Kok) that are investigated for prevailing E and SW wind. The results reveal the critical dependence of ventilation on the urban morphology. Air paths, street orientations, ground coverage, sites fronting the water, inter connectivity of spaces, building podium size and building heights can all affect the pedestrian wind environment. Isolated tall buildings may have a pronounced impact on ventilation both locally and downstream.http://dx.doi.org/10.1127/0941-2948/2012/0356urban large-eddy simulationhigh-density citywind environmentpedestrian level ventilationhong kong |
| spellingShingle | Marcus Oliver Letzel Carolin Helmke Edward Ng Xipo An Alan Lai Siegfried Raasch LES case study on pedestrian level ventilation in two neighbourhoods in Hong Kong Meteorologische Zeitschrift urban large-eddy simulation high-density city wind environment pedestrian level ventilation hong kong |
| title | LES case study on pedestrian level ventilation in two neighbourhoods in Hong Kong |
| title_full | LES case study on pedestrian level ventilation in two neighbourhoods in Hong Kong |
| title_fullStr | LES case study on pedestrian level ventilation in two neighbourhoods in Hong Kong |
| title_full_unstemmed | LES case study on pedestrian level ventilation in two neighbourhoods in Hong Kong |
| title_short | LES case study on pedestrian level ventilation in two neighbourhoods in Hong Kong |
| title_sort | les case study on pedestrian level ventilation in two neighbourhoods in hong kong |
| topic | urban large-eddy simulation high-density city wind environment pedestrian level ventilation hong kong |
| url | http://dx.doi.org/10.1127/0941-2948/2012/0356 |
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