Sitting in his office with the dull hum of the wind tunnel blowing in the background, Eaker is eager to talk about all the people who pitched in to help make his tunnel a reality, how great his small staff of employees is, and how much fun it is to work in racing. But what you won't get him to do is brag about his achievements. It is the meek, after all, who receive the richest rewards. Instead of spending his time talking about what he's done, he'd rather spend his time reading the secrets written in the wind.
The Stationary "Rolling Road"Under each aluminum strip in the floor is a slot for either blowing or sucking air underneath the car. This movement of air adds energy underneath the chassis to simulate the effect of asphalt moving underneath, which allows aero engineers to make a much more realistic simulation of how air flowing all around a race car affects it. The fact that this rolling road is now stable allows for rollers underneath the tires to spin the wheels to match the speed of the air blowing past.
One of the most important factors for accurate wind-tunnel readings is to mimic the characteristics of a car moving across a racetrack or road surface. Spinning tires and the asphalt moving underneath the car have a significant effect on a car's aero characteristics. This is easy to achieve with a scale tunnel because the test models are smaller and typically can be supported with a strut suspended from the ceiling. A large belt can be spun underneath the car to simulate a moving surface.
The same effect is infinitely more difficult with a full-scale tunnel. You cannot effectively suspend a fullsize car in order to spin a large belt underneath it. Eaker's solution was to devise a system of slots in the floor that alternately blow air into the tunnel and suck it back out. The same amount of air that is blown in is sucked out, so the net effect is only to add the energy of moving air underneath the car but not change the volume of air (which can upset the aero effects). This creates the effect of a "rolling road" on a flat, stable surface.
The stable surface is key, because now Eaker can also add rollers under each of the four tires to spin them at the appropriate speed. Tests in the Aerodyne tunnel are usually done with the wind speed at 130 mph, so the wheels and tires are spun to match that speed. The rollers are mounted on moving panels in order for the car to be rotated a few degrees, so the air hits the car from an angle and not head-on. This is important so race engineers can see how a car will react when entering a turn. Eaker's stationary rolling road was the first of its kind in operation when Aerodyn opened for business in 2002.-Theo James