With increased urbanization, tall buildings, and climate change, comfort and safety in terms of wind have become increasingly important in modern urban planning.
Trond-Ola Hågbo defended his doctoral thesis at the Faculty of Science and Technology on March 6, 2025. He defended his thesis Towards Realistic and Efficient Computational Fluid Dynamics Simulations for Urban Wind Applications and Pedestrian Wind Comfort Assessments.
Urban development can change wind conditions at street level, which can create safety and comfort issues. Computational fluid dynamics (CFD) has become an important tool for predicting and analyzing complex wind flows and providing insight into the planning phase of construction projects. The goal of the project has been to develop practical guidelines that can support architects and urban planners in designing safer and more comfortable public spaces.
What have you researched?
"I have been researching how to make wind simulations (CFD) both more realistic and accurate, while also making them more efficient to implement. This includes various aspects of modeling wind in urban areas, such as building geometry, urban structures, and optimizing the number of simulated wind directions," says Hågbo.
He has also researched how to improve wind simulations for urban areas, both in terms of accuracy and computational efficiency.
"The goal has been to develop methods that provide reliable results while being faster and more resource-efficient. The research has included various aspects of wind modeling, such as the selection of geometric details in the urban environment, optimization of the number of simulated wind directions, and evaluation of different numerical approaches."
What did you find out?
His doctoral project showed that it is possible to make wind simulations for urban areas both more accurate and more efficient, without compromising quality.
You don't always need the most detailed building models to get good results. Simplified models can often provide just as reliable answers as highly detailed models, while requiring far less computational time. This makes simulations more practical and accessible.
"The number of wind directions in simulations is more important than previously thought. Many studies use 12 wind directions, but this can be inaccurate in up to ten percent of cases. I found that 24 directions give reliable results in most situations, while 36 is recommended for safety-critical analyses," says Hågbo.
The findings provide practical guidelines on how to optimize wind simulation and make it more accessible to urban planners and engineers.
What can the research findings be used for?
The findings can contribute to better urban planning, architecture and engineering related to wind comfort and safety in urban areas.
"By improving wind simulation methods and making them more accessible, we can ensure that wind conditions are taken more seriously in the design of urban environments. This can ultimately provide safer and more comfortable outdoor areas for people living and traveling in the city."
The findings from the research may:
- Give urban planners and architects better tools to assess and improve wind conditions around new buildings and urban areas.
- Reduce the cost and time spent on wind analyses, so that such studies can be carried out in the early stages, where they have the greatest impact.
- Contribute to better regulations for wind comfort by providing more precise guidelines for how many wind directions should be simulated.
- Used directly in industry, including in the company NablaFlow's product ArchiWind, which is based on parts of the doctoral work, and which already helps engineers and architects take better account of wind in urban planning.
- By making wind analyses easier and more accessible, the likelihood of wind conditions becoming a natural part of urban development increases. This can lead to safer streets, more pleasant outdoor areas and generally better urban environments for most people.
Trond-Ola Hågbo has a master's degree in applied physics and mathematics from UiT and a doctorate from UiS. His research is in the field of mathematical modeling of wind (CFD). He has particularly looked at wind in urban areas and how the geometry of buildings and urban structures affect wind conditions. His doctoral work has resulted in practical guidelines for more accurate and efficient simulations of wind comfort in urban environments. During his doctoral studies, he has helped start a company where one of the products, ArchiWind, is based on the doctoral project. Hågbo now works at ArchiWind. The research was carried out in collaboration with the von Karman Institute for Fluid Dynamics (VKI) and was funded by the Future Energy Hub, UiS.