Inspired by last season trend to switch to biplane front wings, I came out with this idea: eliminate vertical pylons and use the upper wing as the only link with car nose.
I think this solution could allow cleaner air to the underbody, especially in conjunction with no kill/double kill designs.
Moreover the entire wing would flex at speed, closing the gap with the ground, increasing efficiency of the lower wing, running in quasi ground-effect mode.
It looks like the upper element becomes a beam, supporting the lower parts and wing plates.
I thought that flexi wings were discouraged - so, the beam would need to be stiff enough support the aero loads without deflecting past the allowed amount.
To be blunt - I expect that the teams look at the the wing mounts very often. Their compromise will be aero efficiency against the required stiffness/weight.
IF adding stiffness to make the beam work will also adds weight - the aero gain may well be less than the penalty for carrying extra weight. Especially weight forward of the front wheels.
Also, it seems to me that using the top element as a beam would force the inner ends of the wing to be thicker to accept the loads - this would surely compromise the freedom to design the ideal aerodynamic shape here - perhaps negating any benefits.
RH1300S wrote:
IF adding stiffness to make the beam work will also adds weight - the aero gain may well be less than the penalty for carrying extra weight. Especially weight forward of the front wheels.
I remember that many teams in the past season ballasted the front nose,
in order to shift weight to the front wheels. FIA then discouraged this trend with a rule "ad acta".
So I don't think this weight further of the front wheels would be negative, on the contrary!
I'm sure the teams have had a look at that proposal. I don't think it's too heavy, after all rear wings have been constructed that way for a while now. However instead of removing vertical supports on the front wing, they added vertical struts at the rear. So I guess having vertical supports is the better aero compromise for now.
That would carry serious Aero penalties, in one of two ways:
First, you don't stack the wings (bi-plane): what you're doing then, is dramatically increasing the gap between elements in the vertical distance. This degrades performance.
Or, say you ARE stacking the wings. Well, at those kind of heights, you are losing quite a bit of performance.
AeroGT3 wrote:That would carry serious Aero penalties, in one of two ways:
First, you don't stack the wings (bi-plane): what you're doing then, is dramatically increasing the gap between elements in the vertical distance. This degrades performance.
Or, say you ARE stacking the wings. Well, at those kind of heights, you are losing quite a bit of performance.
Well I must disagree with this one. Although I am convinced it is impossible to make such a wing strong enough to make it pass flexibility inspection, it would be beneficial for the centre part of the wing. In fact, driving at high speeds would make the whole wing go down, increasing its effectiveness as it will be closed to the ground.
I’ve seen this design proposed a few times in different forums, probably even here already, it’s something that comes pretty naturally to mind once you see the “biplane” like wings so common nowadays.
Unfortunately that design has a big weak point that is exactly what you describe as the strong point, ie the flexing of the part of the wing close to the ground.
That isn’t beneficial, it’s actually a problem because that part is very close to the ground, so close that sensitivity to ground clearance is very high, meaning that a minimal variation of ground clearance leads to big variations of the wing characteristics, possibly even to stall of the wing.
The result is the possibility of non predictable behaviour in many circumstances, for example in braking, that would create problems to the driver.
That issue, excessive pitch sensitivity, already requires lot of attention in the design of the spoon in a standard wing where, thanks to the vertical mounts, the ground clearance is related only to car’s pitch, it’s an issue big enough as it is without having to worry about flexing, let alone having it.
Besides, also assuming you could make the structure stiff enough to avoid flexing on the central part, that would be possible only eliminating flexing of the tips, that on the contrary is beneficial since these parts are lot more distant from the ground so variation of ground clearance has more predictable effects.
With the current standard design you can have zero flexing where you don’t want it (in the middle) and a bit of flexing where you want it (at the tip), and all that with a very efficient design from the structural point of view.
Furthermore it’s not necessarily true that the vertical supports are so bad for aero, maybe you can shape them so that they can redirect the flow in opportune ways.
A negative aspect of the supports is that they obstruct part of the slot, but that problem, at least for the first slot of a three elements wings, can be solved just moving the mounts from the first element to the second one.
Another thing to consider is the crash worthiness of the wing. It would be hard to have the wing come apart in an incicident without taking part of the nose cone with it.
Hate to hop on the bandwagon, but if you look at the way the rear wing has evolved, from endplates supporting the load, to the twin supports directly beneath the centerline of the rear wing, it becomes clear that support through endplates is not ideal to carry a very large aero load (2000N+). It's hard to imagine how much load is going through such a thin piece of carbon fiber, but it is truly immense. Remember, they jack up the car through the nose cone, so it must also resist bending from that as well.
AeroGT3 wrote:That would carry serious Aero penalties, in one of two ways:
First, you don't stack the wings (bi-plane): what you're doing then, is dramatically increasing the gap between elements in the vertical distance. This degrades performance.
Or, say you ARE stacking the wings. Well, at those kind of heights, you are losing quite a bit of performance.
Well I must disagree with this one. Although I am convinced it is impossible to make such a wing strong enough to make it pass flexibility inspection, it would be beneficial for the centre part of the wing. In fact, driving at high speeds would make the whole wing go down, increasing its effectiveness as it will be closed to the ground.
I am sorry, but I've done enough wind tunnel and CFD testing to know you are wrong.
You gain more by having the flap in an optimum position than you do from flexing the wing and moving it a bit closer to the ground. The biplane effect destroys more performance than that small groundward movement creates.
Also, wings are highly sensitive to height. You move too close and you stall, and downforce with flexing movement will vary quite a lot - which is undesirable.
AeroGT3 wrote:I am sorry, but I've done enough wind tunnel and CFD testing to know you are wrong.
Not necessarily.
Otherwise they wouldn't have bother with the likes of:
I know that biplanes placed close together do not work well normally, but an F1 car is not subject to the same design considerations as an aircaft.
I do also agree with you about the wing movement, however with clever design it should be possible to keep the relative positions between the 2 elements similar (heck, stick in a spacer does most of that). Also, with stalling the wing close to the ground - thats something to iterate through with CFD and FEA. Design it that it doesn't get close enough to stall (maybe don't dip the centre so aggressively, different profile, stronger main plane etc etc etc).
The picture you have posted is very, very different from the original post. The horizontal and vertical offsets are considerably higher as a percentage of either chords.
The low lift coefficients targeted for aircraft use make biplanes a lot more acceptable than they are in motorsport.
