Wind Design in Smart Cities

Cities become denser. We build more and more high-rise buildings, but these buildings typically induce high wind speeds on pedestrian level. As such, high buildings can reduce pedestrian wind comfort and the attractiveness of an entire neighborhood. As cities become denser, the average temperature in our cities increases. Increased temperatures lead to an increased mortality. Wind can help to ventilate streets and dissipate heat. Smart cities are advised to the four aspects: 1) Assess the impact that wind has in your city, but also look at other aspects. 2) Determine the critical areas, and consider how the challenges can be solved. 3) Determine which quality standards you want to achieve. 4) Translate the large-scale solutions and quality requirements into practical guidelines. In general, it can be stated that there are 3 technologies to assess wind in the urban environment: real life measurements, wind tunnel experiments and CFD computer simulations (CFD or computational fluid dynamics). For a complete wind assessment in a city, real life measurements are not recommended. The main advantages of CFD over wind tunnel experiments are: 1) You can visualize the entire wind field, and not only at a few discrete locations. 2) All details in the flow around small balconies or other private places can be studied. The main disadvantage of CFD is that dynamic wind effects like gusts are very hard and computationally expensive to simulate.This Dutch NEN8100 norm describes 2 ways to assess the wind comfort: wind tunnel experiments and CFD computer simulations. The results of the measurements or simulations are combined with local statistical wind data, in order to produce a map with local wind classes. Actiflow is a Dutch consulting company that has extensive experience in performing wind studies according to the NEN8100 norm. An interesting example is the wind study for the Amstel III region near Amsterdam. Actiflow advised the municipality about possible measures in the public space to mitigate wind hindrance and danger and formulated concrete guidelines for individual real estate developments in the area.