Deformation of car mass at high speed?

[littlefarny]

Another crazy idea from moi.

The air going over the car causes downforce, pressing the car into the ground, but does it actually change the shape of the car?
As in, could it instead of just pressing the whole car into the ground, it deforms the shape of certain parts along high speed sections of track to make a more 'slippery' profile?

I know vaguely the outline of the non-flexing FIA rules for F1, but there has been a lot of talk recently about introducing flexible aero, and this is taking it one step further.

You could build a flexible shell around the monocoque that would change shape based on the speed of the air passing over it, hopefully lowering the COD.

Engineering it to have this affect at the point where the air is moving fast/faster would be tricky, but is it actually do-able?

[SidewaysFeltham]

Self defeating.

Greater generated downforce equals greater drag.

Ergo: the slower the car.

[littlefarny]

Why would it create downforce? Surely the continuation of the same speed of air would keep the material deformed (tucked in) not creating any more downforce?
I'm not hot on aerodynamics yet, was just a thought.

[AU N EGL]

Originally Posted by littlefarny

A

You could build a flexible shell around the monocoque that would change shape based on the speed of the air passing over it, hopefully lowering the COD.

Didn't an F1 team get penalized for a semi-flexible wing? at higher speeds the wing would flatten thus less aerodrag and higher speeds. At lower speeds the wing would be curved more giving greater down force.

Movable wings and body parts were banned many many years ago. Adjustments in the pits to increase or decrease the wings angle of attack, YES, but not by the driver or nature.

Heck even exotic very dense metals as in beryllium was banned vs lead wts to lower the CoG.

[littlefarny]

Flexi-tech might be introduced in F1 soon, but it doesn't neccessarily have to be for F1 either.

[tristancliffe]

Wasn't this discussed in Racecar Engineering some time last year? Not just wing flexing (as in F1), but the whole body profile - sidepods, engine covers etc deforming by the careful stress/strain analysis of panels - to reduce drag at speeds higher than the fastest corner (i.e. at speeds when you don't need downforce).

[Notso Swift]

In short, yes
But you also need to control what parts deform and by how much at what speed. Otherwise yo may have a worse shape with less downforce and more drag
Way too hard for the likes of me!

[Smokey 6 litre]

Because all structures deform under load to some extent it is entirely possible to predict the deformation and use it to lower the drag of the vehicle at high speed, taking it the extent of the entire car shell deforming is an interesting concept.

It would take massive amounts of CFD and Windtunnel simulation but it is already employed to an extent by some F1 teams, i recall Red Bull having to stiffen some components in the rear wing structure because it was deemed to be moving too much, and the row about Ferrari's 'flexi-floor' at the begining of last season.

Problems arising from continued deformation of body pannels are the expense of development and worries about material fatigue caused by the continued loading and unloading of the structure.

[Locost47]

A few years ago i got involved in something along these lines for a NASCAR project, as the spec 'jelly mould' bodies seriously limited the scope for proper aer development. There weren't rules on the fixing locations, however, and so some development was done on allowing certain panels to be quite poorly supported and thus to deform under aero loading, primarily to reduce drag, rather than generate downforce.

In F1 flexible aero surfaces have been and still are used to affect the performance of front and rear wings. At least two teams have used flexible rear wing mounts which bend backwards under load and reduce the effective incidence of the rear wing. At least one has used poorly supported wing sections which allow the gap between the rear wing mainplane and flap to close up at high speed, thus stalling the wing and dumping a lot of downforce-induced drag. Since this was addressed with the mandatory slot-gap separator, another team has found a way of achieving the same thing using flexible carbon weave in the construction of their wing profiles, so that the aero surface deforms due to the pressure distribution around it, changing its shape enough at high speeds that it stalls.

All of this is comes from hearsay from people involved in F1 aero and therefore comes strictly under the "allegedly" caveat, and i'm not making any allegations in any specific directions, your honour.

[dtype38]

Not too long ago a certain F1 team with predominantly red livery used an ingenious method of attaching the upper elements of their front wing to the sides of the nose cone with "stretchy" fasteners while the lower element was mounted rigidly. At speed the downforce caused the lower element to flex and pull the upper element to pull away from the bodywork. This not only caused flex in the elements, but also allowed dumping of upper to lower surface pressure difference, presumably to lower downforce and therefore drag. Only trouble with the whole idea was that they had a forward facing onboard camera mounted on the side of the nose just aft of the upper element, and when the director cut to that camera angle the wing element could be clearly seen pulling away from the body as the car built up speed... doh!