**Trondheim, one of Norway’s windiest municipalities, recently enlisted the help of NablaFlow to investigate the possibility of extending the use of Granåsen Ski Centre to also include a big jump to facilitate freestyle skiing and snowboarding Big Air events.**

Located in Trondheim, Granåsen Ski Centre is known for hosting World Cup and Continental Cup ski jumping competitions as well as world-class biathlon and cross-country skiing competitions. The Centre has one normal-sized hill (K-90) and one large hill (K-124). The proposed plan would require the removal of parts of the existing forest and reshaping of the terrain to form the big jump and necessary landing and entry area.
However, the modification to the surrounding area of the ski jumping facilities could  affect the wind conditions, potentially worsening the conditions for the jumpers. Therefore, Trondheim kommune wanted to be informed on the likelihood and extent of the possible implications.

![Streamlines coming from the simulation run with ArchiWind, crossing the Ski Centre Area](https://nablaflow-cms-uploads-production.s3.eu-west-1.amazonaws.com/8_330e75c7e8.png)
_Streamlines coming from the simulation run with ArchiWind, crossing the Ski Centre Area_

NablaFlow conducted a CFD (Computational Fluid Dynamics) investigation of the impact of the proposed modification to the forest and terrain on the wind velocities and turbulence at the ski jumping facility. The firm used their ArchiWind tool and developed and applied some project-specific extensions to their fully automated platform to include the modeling of the effect of the forest on the wind conditions.
Simulation results showed that the big air jump would affect the local wind conditions around the big air jump but not notably in the ski jumping arena. The information obtained from the simulations allowed Trondheim kommune to make an informed decision on implementing the proposed plan. It also ensured satisfactory similar wind conditions at the ski jumping arena after implementing the modification to the forest and terrain neighboring the ski jump arena compared to before the project.

![Comparison of the wind velocity before (left) and after (right) the construction of the Big Air Jump. These images are referring to only one of the 16 wind directions taken into account for the wind analysis.](https://nablaflow-cms-uploads-production.s3.eu-west-1.amazonaws.com/7_42af5e1d70.png)
_Comparison of the wind velocity before (left) and after (right) the construction of the Big Air Jump. These images are referring to only one of the 16 wind directions taken into account for the wind analysis._

In conclusion, the study undertaken by NablaFlow for Trondheim kommune allowed for a thorough investigation into the potential effects of extending the use of Granåsen Ski Centre while ensuring the preservation of satisfactory wind conditions for ski jumping competitions.

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Urban Wind Engineer at NablaFlow, Trond-Ola, has a strong background in energy, climate, and environment, and he is currently completing his Ph.D. studies in computational fluid dynamics.

Trond-Ola has spent several years at NablaFlow researching and developing tools to simulate wind flow within the atmospheric boundary layer, focusing on urban areas. These tools form the core of ArchiWind. Trond-Ola has a passion for nature and the environment and believes that ArchiWind can be used to tackle emerging urban wind challenges related to extreme weather events powered by climate change. These include pedestrian wind comfort and safety, city ventilation related to heat waves and pollution, and urban wind power production.

Trond-Ola Hågbo

How NablaFlow's CFD Investigation Provided Valuable Insight for Trondheim Kommune's Decision Making Process.

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Investigating the Possibility of a Big Jump for Freestyle Skiing and Snowboarding at Granåsen Ski Centre