Analyzing the behavior of a long span bridge or of a slender tower in high winds, a pergola in driving rain or a train moving at high speed. Testing the functionality of automotive prototypes, equipped with internal combustion, hybrid or all-electric engines, driving through snow, or military equipment subjected to Saharan heat. These are examples of studies performed by CSTB experts using the Jules Verne climatic wind tunnel in Nantes. Modernized and enlarged to address emerging challenges, the Jules Verne wind tunnel is now a research facility unlike any other in the world. Installed on more than 6,000 sq. meters, it can simulate and analyze the behavior of structures or systems up to full scale, in weather events which may be extreme. The synergy between the physical and digital models has been increased, in order to offer an optimized setting in which to respond to and better understand the problems posed. The wind tunnel team guides professionals in improving the design of their products, based on the weather conditions to which the products will be subjected, in enlarged workspaces that have been adapted for the comfort of the people working there.
Improving structures and products based on their climatic environment
The construction of major structures (towers, bridges, stadiums, museums, etc.) or buildings with architecturally complex or slender shapes requires knowledge of their behavior during climatic events. This is also true for civil engineering infrastructure; sea, air and ground transportation and military equipment.
Freezing temperatures at −32°C, extreme heat at +55°C, snow, rain, ice, fog, sandstorms or dust storms, and hurricanes with winds up to 280 km per hour: all types of weather, including extreme conditions, can be re-created in the CSTB Jules Verne climatic wind tunnel. The advantage here is the ability to reproduce atmospheric phenomena occurring simultaneously. The static and dynamic behavior of a structure (or other system) can be analyzed up to full scale, in widely diverse climate conditions.
Using their expertise in climatology, physics and aerodynamics, CSTB experts offer economic stakeholders programs specific to their projects. Testing in the wind tunnel, possibly combined with digital methods, enables an immediate determination of the behavior of the structure or system being studied. These results constitute data that is essential to check the stability and functioning of the structure or system, so that its design can be improved, thereby enhancing user safety and comfort.
All of the sectors concerned
Reproducing the combined effects of wind and other climate parameters
The Jules Verne climatic wind tunnel has two separate closed circuits. These offer 5 separate test areas, in which the system to be tested is installed.
In the dynamic circuit, 6 powerful fans (3200 kW in all) reproduce airflow in 4 test sections. This makes it possible to re-create:
- Airflow up to 280 km per hour in the aerodynamic section;
- Turbulent winds combined with heavy rain and/or a sandstorm in the atmospheric section;
- Moderately turbulent airflow up to 160 km per hour in the airflow section;
- Low-noise wind in the aeroacoustic section.
Simultaneously with airflow, the wind tunnel can re-create the effects of tropical sunlight, or the effects of cold or heat, from -32°C to +55°C, in its thermal circuit. It reproduces:
- Solar radiation and radiant flux;
- Various types of precipitation: rain, fog, snow, frost, hail;
- Different humidity levels (tropical climates require 95% humidity for temperatures from 30°C to 35°C);
- Simulation of a vehicle driving with its engine running and wheels turning.
The experimental approach is aptly supplemented by digital simulation of flows to size wind tunnel experiments beforehand or better understand phenomena, thus facilitating the analysis of measurement results. The augmented reality application Xpérience, developed by the CSTB, allows remote viewing of the results of these combined approaches. Accessible, educational and intuitive, it facilitates exchanges between the teams working on a given project.
The modernization work on the Jules Verne wind tunnel was co-financed by the Pays de la Loire and the European Regional Development Fund (ERDF).