5. Aerodynamic effect of vegetation on urban microclimate

Wind tunnel study of aerodynamic effect of vegetation (Flora) and Sihlcity Green Wall (Zurich, green-walls)
Wind tunnel study of aerodynamic effect of vegetation (Flora) and Sihlcity Green Wall (Zurich, green-walls)

 

Background


Urban heat island (UHI), a phenomenon that an urban area has higher air temperature than that of a rural area, has attracted increasing public concern in recent decades in the time of climate change since it imposes urgent challenges to health of inhabitants and resilience of many societal systems. A potential mitigation measure attracted extensive research interest is to employ more vegetations in streets, on roofs and building façades. The presence of vegetations affects urban microclimate as a result of multiple mechanisms, for instance, evapotranspiration effect, shading effect, aerodynamic resistance to wind and heat transfer, etc.

While the evapotranspiration and shading effects have been examined extensively by the research community, understanding of aerodynamic resistance of vegetations at street and neighborhood scales is still limited. Insight into the influence on airflow and heat transfer is crucial for guiding vegetation implementations for urban heat island mitigations.

 

Keywords

Wind tunnel measurements, Particle image velocimetry (PIV), Computational fluid dynamics (CFD)

Labels

Master Thesis

Description

To understand the aerodynamic effect of façade vegetations on heat transfer and airflow, experimental investigations will be implemented using particle image velocimetry (PIV) and thermal field measurements in the wind tunnel at EMPA (Swiss Federal Laboratories for Materials Science and Technology, Dübendorf). Scaled-down buildings and temperature controllable façades will be adopted in measurements. Flow structures and temperature fields in non-isothermal street canyons with various vegetation properties are expected to be revealed in the project.

Goals and task

  1. Design experimental measurement matrix
  2. Implement PIV and temperature field measurements
  3. Perform analysis with the experimental data and conclude implications
  4. Conduct numerical simulations to perform parametric studies of vegetation properties

 

Contact details

Please contact Dr. Yongling Zhao () for further information.

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