Sauber talks about the new windtunnel

The new Wind Tunnel
By Phil Huff
February 9 2003

"Aerodynamics is the primary factor affecting a modern Formula 1 car. Consequently, the wind tunnel is the primary tool for creating a successful racing car," says Peter Sauber.

"In recent years, the top teams have significantly increased their investments in this field. It was therefore a logical decision for me to build a wind tunnel that sets new benchmarks," explains Peter Sauber. "It was important for us to build a facility that is not necessarily tied to Formula One use. Our wind tunnel in Hinwil will enable us to test production road cars up to and including the size of vans."

Plans for building a wind tunnel at Sauber's premises in Hinwil date back to 2000, with the ground-breaking ceremony for the 70-million-Swiss-franc project held in October 2001. Providing that the project continues to stay on track, the facility will be commissioned at the end of 2003, enabling the aerodynamic development of the Sauber C23 to be continued in the new facility during the course of the 2004 season. The first car to be developed completely in Sauber's own wind tunnel will be the C24.

Regarding factors such as wind speeds, the size of the test section and the models, the dimensions of the rolling road and the model motion system as well as data acquisition technology, the Sauber facility will compare favourably with any of the existing Formula 1 wind tunnels. Sauber's technical director Willy Rampf sums up the facility's potential: "We are convinced that the total scope of its features will be setting new benchmarks within Formula One".

The wind tunnel is of a closed-circuit design. The maximum length and width of the steel tube is 62 metres and 28 metres respectively, and the largest tube diameter is 9.4 metres. When operating under full load, the power consumption of the system amounts to 3000 kW. This enables wind speeds of 10 to 80 metres per second (i.e. nearly 300 kph) to be reached in the test section.

In order to expand the testing capabilities beyond 50% and 60% scale models to production road cars, up to and including the size of vans, the test section will be unusually large. With a 15-square-metre cross-section and a particularly long rolling road, the test section of the Sauber facility is larger than that of any existing wind tunnel fit for Formula One level testing.

In order to simulate side-slip conditions up to a maximum angle of 10 degrees, the entire measuring platform can be rotated. The platform is fitted with a steel-belt rolling road. This is required to accurately simulate the relative motion between the vehicle and the road, as well as the rotating wheels. The "Flat-Trac" rolling road system built by MTS for the Sauber wind tunnel is currently the largest of its kind in the world.

The exceptionally wide moving steel belt reaches the same velocity as the air stream, nearly 300 kph. Located underneath the moving belt are load cells, which are used to measure the wheel lift during tests. MTS also supplies the model motion system, a special overhead suspension system for the models.

Sauber's decision in favour of a longer than standard layout for the test section was based on a specific consideration. This layout allows two models to be positioned one behind the other, enabling slipstream and air turbulence simulations. "Due to their highly efficient aerodynamics, modern Formula One cars are particularly vulnerable to changes in air flow. For the first time, this test configuration now enables us systematically to measure these influences and to take appropriate corrective action," explains Rampf. "Moreover, given the additional possibility of testing full-size Formula One racing cars, factors such as the cooling or the air flow around the driver's helmet can be measured precisely."

The measuring devices represent a joint development by Sauber's specialists in conjunction with RHS and MTS. These two companies supply the complete control, display and load measurement system, including tailor-made software. The system combines the benefit of obtaining extremely precise readings with high-level data acquisition efficiency.

In addition to boasting impressive dimensions (65-metre length, 50-metre width, 17-metre height, 63,000 cubic metres of construction volume), a glass faﾧade aims to convey the unique character of the facility that combines its industrial purpose with that of a museum.

Although presenting the exterior impression of a homogenous hall, the facility actually comprises two clearly separated elements. These are the wind tunnel hall itself and a multi-storey wing that accommodates work areas, a hall for special events and the Sauber museum. The wind tunnel hall will serve as a representative area. For special events it can be sectioned off from the working area by glass walls.

In addition to the lobby, the ground floor houses the Sauber museum, exhibiting a representative selection of competition vehicles that document the history of the successful Swiss racing car constructor. A room for special events located on the first floor can accommodate 80 people. This room can be used by Sauber's partners and sponsors for hosting marketing or customer relations events as well as seminars in a truly unique setting. Making full use of the entire space available allows the hosting of up to 300 people.

The second and third floors are occupied by two identical workrooms. The two floors are earmarked for Sauber's use. In addition to the engineers working in the wind tunnel, model designers, model builders, CFD specialists and other members of the aerodynamics team will use the area.

Nevertheless, the design of both levels allows them to be made available to customers, if needed. The infrastructure even enables two different teams to work in the building at the same time, without ever meeting face to face.

Peter Sauber's closing comments: "The new wind tunnel, in terms of its overall concept, is truly unique. It visibly documents our prime objective of continually improving the competitiveness of our team and of ensuring that Hinwil remains an attractive location in the long run."