n smikle wrote:these are some of my random brainstorming.
Maybe:
1. The wing profile is physically too thin to practically implement the F-duct?
2. The flow behavior behind the skinny wings doesn't get triggered the same way as a full wing?
3. If the stalling of the wing works.. maybe it is canceled out by turbulence around where the F-duct attaches to the wing?
4. The F-duct trigger hole cannot get activated on a low DF setup?
With the caveat that I'm by no means an aero-bod, my understanding of it is this:
The reason that the f-duct works is that the force produced by the upper element of a typical F1 wing has a significant rearward component as a result of the wing being so steep*. With a more classic design of wing, such a a typical aircraft wing, drag increases when the wing is stalled. This still happens with an F1 wing, but the rearward component of the force produced by the unstalled wing is greater, resulting in a net loss of drag. The shallow angle of a Monza style F1 wing means that is doesn't produce a rearward force large enough for the f-duct to be effective.
This means that the decision on whether to run the f-duct or not comes down to whether a second element that's steep enough to allow the f-duct to be effective can be introduced without losing too much top speed. The main benefits being higher speed through the parabolica and faster, more stable braking. I expect it's mostly going to come down to the effect on top speed rather than lap time, since if you're giving away too much on the straights you'll just get mugged for track position even with your better braking and cornering.
* Don't confuse this with a steep angle of attack. The way the two elements of an F1 wing interact mean that the effective angle of attack of the upper element is nothing like as steep as it looks.