A certain Professor Eberan-Eberhorst, from experience gained by recent wind tunnel experiments, rebuild an AU car destined for breaking speed record. The Auto Union technicians had, by covering the underside of the car with "skirts", in fact created a ground effect car only ~40 years before the Lotus 78/79.
Unfortunately german ace Bernd Rosemeyer was killed in this monster.
MB on the other hand decided to take another path, inverted airfoils, the result being the T80 record car.
Briliant revolutionary work, decades ahead of its time. But came WWII and all this interest in downforce and drag would be lost till the 1960s.
Now onto Can-Am and F1:
a few clarifications (witch I posted before on other treads)
As you can see there is blue beneath and above the car. Blue is downforce, red is drag.
The diffuser is usually found on each side of the central engine and gearbox fairing and is located behind the rear axle line as seen in Figure.
As seen in Figure , the diffuser consists of many tunnels and splitters.
It is designed to carefully guide and control airflow underneath the racecar.
Essentially, along with the flat bottom (and previously the big and low front wing now gone), it creates a suction effect on the rear of the racecar and pulls the car down to the track.The suction effect is a result of Bernoulli's equation, which states that where speed is higher, pressure must be lower.Therefore the pressure below the racecar must be lower than the pressure at the outlet since the speed of the air below the racecar will be higher than the speed of the air at the outlet. Racecar engineers must carefully design the diffuser, since its dimensions are limited by the racing regulations and its angle of convergence is somewhat restricted.If the angle of convergence is too great then the flow will separate because of the adverse pressure gradient.
The problem with downforce is that it comes with drag so there 2 solutions for creating "downforce on demand"
1] the Chaparral movable aero/wing.
Basicaly the wing moves to switch between low drag and high downforce.
2] the active suspensions
Basically car goes up air goes freely underneath drag is reduced, car goes down the air is compressed/accelerated (by the flatbottom and diffuser) the pressure drops (Bernoulli's principle ) resulting downforce.
Today, in F1, the time between a wing is conceived and until it becomes a museum piece is just 6 week. And will be used for at least 1 race to a maximum of 3 races.
Every track demands modifications or downright redesign of aerodynamics, suspension (along with these maybe even brakes), and even some weight tweaking, all very costly and time consuming.
So why not use these "ancient" solutions ?!
Edited by DOF_Renault_BMW, 15 October 2007 - 10:09 PM.