Page - 86 - in Intelligent Environments 2019 - Workshop Proceedings of the 15th International Conference on Intelligent Environments
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Inputted air temperature 34.7C, radiation 2.03 MJ/m 2
and wind speed 2.6 m/s blowing
easterly. In this case, wind is blowing in perpendicular to major street canyons
approximately in the same way as for 11.00. The location of overheated spaces is
therefore almost similar. However, the amplitude of overheating is less important
because the amount of radiation is less important although inputted wind speeds are
lower as this does not matter when ventilation is blocked by different building clusters.
Figure 9. Air temperature simulations for hour 14.00 within the real environment of Shimbashi (left) and
Minamidai (right) at pedestrian level, Tokyo, Japan.
Inputted air temperature 34.7C, radiation 2.84 MJ/m 2
and wind speed 3.6 m/s blowing
south easterly. The wind is blowing diagonally towards south in this case. This affected
the patterns of the spatial distribution of air temperatures. Temperature levels increased
due to a high amount of radiation. Temperature levels massively increased within the
shallow canopy of the residential district of Minamidai because the design of building
blocks is arbitrary and blocking the wind ventilation by creating many recirculation
zones although wind speeds were not insignificants. The amplitude of temperature
levels within the deep canopy of Shimbashi were less important because high-rise
buildings catch winds and accelerate them downdraft and this removed heat and
ventilated some open spaces.
Conclusion
The dynamic approach using an integrated code for energy balance and RANS CFD
was tested by using measurements from the COSMO model in Japan. Air temperature
patterns and amplitudes fit well between measurements and calculations. This newly
developed approach brought more information in terms of the calculation of unstable
urban thermal stratification over longer time periods within local boundary layers,
especially above and within the upper levels of an urban canopy. This was very clear
when the amount of radiation was important which corresponded to hour 10.00 of the
simulation. This approach however underestimated air temperature near the ground
surface as surface temperatures were quite underestimated. The patterns of temperature
distributions were more interesting and informative. The model was tested in real
environments and highlighted the fact that deep and/or shallow urban canopies, the
urban design of different building blocks and street canyons, wind speeds-direction and
the amount of radiation were very important factors for the estimation of overheating
within real urban settings. The dynamic approach will bring more information to local
urban planning policies aiming to tackle climate change issues such as urban warming.
M.Bakkali andY.Ashie /RANSModelling
forLocalClimates,EnergyUseandComfortPredictions86
Intelligent Environments 2019
Workshop Proceedings of the 15th International Conference on Intelligent Environments
- Title
- Intelligent Environments 2019
- Subtitle
- Workshop Proceedings of the 15th International Conference on Intelligent Environments
- Authors
- Andrés Muñoz
- Sofia Ouhbi
- Wolfgang Minker
- Loubna Echabbi
- Miguel Navarro-CĂa
- Publisher
- IOS Press BV
- Date
- 2019
- Language
- German
- License
- CC BY-NC 4.0
- ISBN
- 978-1-61499-983-6
- Size
- 16.0 x 24.0 cm
- Pages
- 416
- Category
- Tagungsbände