The researchers involved with the wind tunnel at DTU Risø Campus has made this short video showing how to easily remove the walls in the wind tunnel.
The Poul la Cour Tunnel can be operated in two different configurations. The first is the aerodynamic configuration with hard walls and acrylic glass windows. Secondly is the aeroacoustic configuration with Kevlar walls so that the aerodynamic noise generated at the surface at the wind tunnel models can emit through the walls.
Since it should be possible to change the configuration from time to time and preferable rather fast, we should not spend too much time doing this.
In the video above you can see how we remove the hard walls in the aerodynamic configuration.