Here a better pic. It doesn’t look like there’s a relevant difference in the vertical positioning of the two wings.
http://www.f1total.com/bilder/show.php? ... &d=2&b=073
West wrote:
Usually in a main plane/flap setup the second wing energizes the flow on the main plane, such that a higher angle of attack can be used; I forgot if it is the first or 2nd element or both. The energization helps prevent seperation such that this angle can be increased, instead of if the element wasn't there. I probably need correction on this though since I haven't looked at my aero book in a while.
Since, because of the presence of the second wing, the peak of velocity on the nose of the main plane is increased, you shouldn’t use a larger angle of attack on the main plane, this could lead to stall. In fact you can see that in the rear wings typically the nose of the main plane is curved upward, the aim is to have a smoother radius at the nose (similar to one of the effects of the leading edge flaps on airplane wings).
It’s on the second airfoil that you can increase the angle of attack thanks to the blowing of the flow from the high pressure side of the main plane (passing in the gap between the airfoils) that improves the energy of the boundary layer on the low pressure side of the second wing.
I can barely notice the difference in angle of attack in both wings. It just looks like hte 2nd one is higher than the 1st one, and both wings having similar dimensions.
In fact, as visible from both pics, the geometrical AoA of both wing is almost the same or just slightly different. But it wasn’t my intention to suggest that there was a difference in the Renault case, at that point I was talking about tandem wings in general as in the typical main plane + flap design. Sorry if it wasn’t clear enough.
