Climatic wind tunnel helps Audi at Le Mans

Climatic wind tunnel helps Audi at Le Mans

• Only three weeks before the 24 Hours of Le Mans
• New Audi R18 TDI tested extensively in climatic wind tunnel
• Valuable findings for cockpit, windscreen and windscreen wiper

Ingolstadt, May 19, 2011 – Premiere for Audi Sport: the Audi R18 TDI, with
which Audi Sport Team Joest contests the 24 Hours of Le Mans on June 11/12, is
the first Audi race car to be developed with the aid of the new climatic wind
tunnel.
Since the beginning of 2008 the climatic wind tunnel completes the Audi Wind
Tunnel Center in Ingolstadt. It creates temperatures between minus 25 and plus 55
degrees Celsius and allows engineers to generate freezing cold and blisteringly hot
wind speeds of up to 300 kilometers per hour. The simulation of sunlight and rain
are also possible.
Especially for the Audi R18 TDI, the opportunity to use the climatic wind tunnel
operated by their production colleagues was extremely valuable for the Audi Sport
technicians. The new LMP1 is Audi’s first closed Le Mans sports car since the R8C in
1999. “The climatic wind tunnel is an example of the extensive cooperation with
Technical Development (TE),” explains Dr. Martin Mühlmeier, Head of Technology at
Audi Sport. “The TE develops constantly and as part of TE Audi Sport is allowed to
use these resources. Conversely, our colleagues from production development
benefit from our findings from motorsport.”
Work on the R18 TDI in the climatic wind tunnel focused on three areas: optimized
airflow through the cockpit, the windscreen and testing the windscreen wiper. “In
this case we can rely on the findings from the climatic wind tunnel – it’s a great
benefit to have such an extremely high quality tool available,” says Christopher
Reinke, Technical Project Leader for the R18 TDI. “The results of everything which
we have tested in the climatic wind tunnel up to now have been confirmed during
testing on the race track.”


In the climatic wind tunnel ventilation of the closed cockpit was optimized to such
an extent that the R18 TDI will manage without air-conditioning at Le Mans. As this
costs both weight and power the engineers were happy to exclude the use of such a
system. The deposit of rain water or solid materials such as sand, rubber pick-up and
stones was also simulated. “We made many valuable discoveries in this area on the
full scale car in the climatic wind tunnel and modified several things and especially
in the airflow area,” says Dr. Martin Mühlmeier. “The reflective film on the roof was
also validated with findings from the climatic wind tunnel. These are all important
details to guarantee a good climate around the driver in the cockpit.”
The silver film helps to prevent the cockpit heating up too much due to the solar
radiation. The Automobile Club de l’Ouest (ACO) regulations stipulate that the
cockpit temperature must not exceed 32 degrees Celsius when driving if the
maximum ambient temperature is 25 degrees. If it is warmer the cockpit
temperature may climb by a maximum of seven degrees. The R18 TDI complies with
these strict requirements thanks to extensive work in the climatic wind tunnel.
The new Le Mans sports car’s single-arm windscreen wiper was also developed in the
Audi Wind Tunnel Center. “This subject is not as trivial as it would perhaps appear,”
says Dr. Martin Mühlmeier. “We do indeed have experience from the DTM. However,
the windscreen wiper is hardly ever used here. Also, a DTM car reaches 250 km/h and
not 330. The demands on the windscreen wiper are considerably higher at Le Mans.”
Fogging and soiling of the complexly formed windscreen which, in contrast to a
production car, is curved in not just one direction but two, is manufactured from
plastic and was also tested in the climatic wind tunnel. The screen is heated to
prevent fogging. For possible soiling a three-stage plan was developed which,
subject to the level of soiling, allows for simple wiping, wiping with detergent or the
removal of one of several layers of rip-off films.
Windscreen soiling is one of the concept specific disadvantages which a closed Le
Mans sports car brings. However, as a result of work in the Audi climatic wind tunnel
the disadvantages were minimized as much as possible.
Audi Communications Sport/acreditated media press.