kilcoo316 wrote:
It will if the local static/dynamic pressure is influencing another surface (e.g. some of the first, and all of the second flap on the lower plane)
It's ot dynamics pressure!!!! It's freestream kinetic energy per unit volume
kilco wrote:
I'm not talking about muli-element flap configurations, I'm talking about mounting a small element directly above the main plane of the wing.
Well I am, and so was the original thread. You keep reducing the size of that bi-plane element smaller and smaller each post to make it fit your point better. Yes, a tiny flap can help, even in a biplane conig, as their suction peaks are very weak. But the original poster's design is a a flap that's as big as the main element itself. When a flap is that big, it ceases to be a flap!
AeroGT3 wrote:
Like the current Renault, Ferrari & Williams front wings.
Which have upper elements about five times smaller than that of the original poster's. Again, I am not talking about F1 designs, I am talking about the OP's design. Between switching from his design to either F1 cars or aircraft, you cannot seem to stay on topic! We are talking about the original poster's design. Please stick to that!
AeroGT3 wrote:
Its true that F1 cars operate in mostly a highly turbulent flow regime, whereas aircraft operate in mostly clean air, without the presence of a ground plane. However, aside from the diffuser, downforce is generated in essentially the same way as lift on an aircraft - a horsehoe vortex system consising of 1 bound and 2 lift dependant vortices.
Yes, the two share Prandtl's lifting line, but that's about it. Again, the math is the same, the application is totally different. Commercial aircraft need Cl's way less than 1, have smooth upper's to avoid shocks, low camber, very low drag, high AR, etc. There is no ground effect and the flow is highly laminar before it hits the wing.
Working the airflow around the wheels and body work as efficiently as possible is another element to it.
It's the main element to it (pun intended.) The upper flaps hurt Aero performance for the wing itself. Simple as that. They positively affect aero perf. over the tire, so its a compromise. Some teams go for it, others do not.
AeroGT3 wrote:
People use endplates because they don't negatively effect the pressure distribution over the upper surface of the first element. A boxed wing does. This is why endplates are ubiquitous and box wings are almost always throw out after testing. (See the sauber post below)
I do accept that biplanes can be a negative influence on each other dependant on chord spacing etc. However, I do not accept there is no place for them with careful design - if it were true they were useless they would not be seen on any cars - never mind the 2 cars that finished 1st and 2nd in last years WCC.
I am not arguing against them as being useless everywhere, they are only useless for wing performance. Why do you not see them on rear wings? Why are they not on any STOL or ESTOL aircraft? Or any aircraft at all?
The fact is, THEY HURT THE WING'S PERFORMANCE. The ONLY time you see them is on SURFACES IN FRONT OF A TIRE. This is because they have NO wing performance benefit, but rather a huge benefit to the tire's aero performance.
Why is it that, if they're so great, they're not on both front and rear wings? [/b]
