Floor rules 2009+

[axle]

Just a thought, does the floor have to be flat, at its extremities as well as under the bodywork? And can any part of it be missing as long as it doesn't have bodywork above it?

If it doesn't have to be flat and can be opened in areas not covered by bodywork I am wondering if there is scope to reduce pressure at the front and down the side of the floor whilst maybe also investigating air feed and exhaust for the sidepods.

I'm not sure there is benefit to be gained but I'm wondering if there is legally potential.

[Fil]

Like this with the rolled edges?





seems like the floor doesn't have to be flat. i wonder whether that relates to the boywork rule.. as in, if there is bodywork above the floor, it must be flat, otherwise do as you please..?

[axle]

Indeed that's the obvious example from this year, I'm wondering how much freedom is in this area...

Wondering if there is scope to extract more air from underneath where there is no bodywork.

[Fil]

like extending those diffuser channels further into the floor, or creating channels along the floor to direct air better?

where are the aero engineers for this topic? they should be jumping all over this for creativity & knowledge!

[axle]

like extending those diffuser channels further into the floor, or creating channels along the floor to direct air better?

where are the aero engineers for this topic? they should be jumping all over this for creativity & knowledge!

Indeed
And slot cutting to remove pressure.

[kilcoo316]

where are the aero engineers for this topic? they should be jumping all over this for creativity & knowledge!

Its a mandated flat floor... and the more floor area you have = less leakage = more downforce.


Quite simple really.

I suppose they have (or should have) tried a sawtooth side to the floor, but I'm not sure how advantageous it would be in sealing the floor fluidically compared to existing solutions.



McLaren's cutting of 2 large holes in the floor this year was a desperate attempt at a remedy to fundamental problems with the aerodynamics of the car. Not optimal.

[Fil]

and the more floor area you have = less leakage = more downforce.

what do the rolled edges on their floor achieve?

[Mystery Steve]

and the more floor area you have = less leakage = more downforce.

what do the rolled edges on their floor achieve?

Probably to pull more air underneath from the sides? At least more smoothly...

[ESPImperium]

and the more floor area you have = less leakage = more downforce.

what do the rolled edges on their floor achieve?

Probably to pull more air underneath from the sides? At least more smoothly...

As the RB5 and STR4 had on Neweys design as well as parts of the FW31 and F60 design.

Especially from any wake from the front tyres. The area im expecting more exploitation is the areas ive pin pointed in this photo montage.



Basically, get more air under the floor towards the rear centre section as you can, then thru the diffuser for a massive ammount of % gain in downforce. Maybes as much as 5% could be gained over the winter, maybes more.

I think if you had a venturi in that area funneling air to say a RB5 style DDD entry, id expect alot of downforce gain from it.

Exploit that area, with under the drivers legs, and with a good front aero map from the front wing, and ill say that car will dominate the season.

[axle]

I'm confused I thought the idea with Ground Effects was to remove air from under the car ergo the air pressure difference pushes car down. You're say that they want to put more air under the car?

I'd have thought the place you want more air is above the diffuser to increase the pressure difference...is that not correct?

[wesley123]

i believe they want air under it to raise the pressure under the car itself, but then at the diffuser this pressure drop is probably larger, thus more suction. also if you have less air over the diffuser you have less problem with the air conflicting each other. What you want to draw air out of the diffuser is low pressure around it, thats why they use gurneys on the diffusers edge, it creates low pressure behind it encouraging air to flow out of it, enhancing its function.(please correct me if im wrong)

[BreezyRacer]

I'm confused I thought the idea with Ground Effects was to remove air from under the car ergo the air pressure difference pushes car down. You're say that they want to put more air under the car?

I'd have thought the place you want more air is above the diffuser to increase the pressure difference...is that not correct?

You are correct sir! These rolled edges, etc are methods of extracting air pressure from the floor area, NOT to increase it. They are closely aligned with Vgs coming off the splitter area to create a low pressure center as far forward in the chassis as possible.

[ringo]

I am of the impression that less air is better, as long as it keeps up to speed to keep down the pressure , but there will also be a respective lower pressure behind the car when the air comes out from under it. Lower pressure behind the car means more drag force. So i think there is a balance with how much air is to be admitted underneath.

The ideal case is to have zero air under the car like a vacuum. I always get a little confused when i read about feeding air under the car. But what i also understand, in reality a vacuum is not possible with the regulations, so the next logical thing is to have less air underneath.Unfortunately less air runs the risk of low momentum and with friction between the floor the air and ground, there is going to be a decrease in velocity resulting in unwanted increase in pressure.
Feeding air underneath is just a way of making sure the air is energized to flow as fast as possible along the length of the car. I don't think the intention is to ram air under the floor. It's just to keep up the velocity.
In an ideal world there would be no boundary layer friction and no need to worry about friction losses, then less air is always better.

I think this car, the chaparall 2j went to the extreme with sucking air from underneath but it had to fans so no worries about energy dissipation.

[PlatinumZealot]

The air is coming from one source so some of that same air has to go over the car and the rest underneath. Less on the bottom and more on the top (like a suction cup) give more pressure differential.
Remember the Fan cars? the fans were sucking the air out from under the car.

For the diffuser I like to think of it simple like this:

The diffusers allow air to leave from underneath the car and join back the free air stream with the least amount of restriction.

The front splitter behaves like a nozzle to increase the speed and lower the pressure under the car. The diffuser's job is to aid the "nozzle" by allowing the air to leave from underneath in a way that the air in the throat of the nozzle (venturi if you like) does not get "backed up" due to energy loss by friction and turbulence etc.

They use diffusers in Water pipes, gas turbines, AC vents and some other things that want to achieve a smooth pressure transition and low energy loss.

I think a problem arises when you lower the ride height too much to make the nozzle area under the car smaller. The air flow will come down the boundary layer at the surface of the road. Because the boundary layer is near the surface of the track the air moves slower because of friction, and so the pressure is going to get higher. And as you go from the front to the front to the back of the car the friction slows down the air even more and the boundary layer gets higher. I think that is why they "Rake" the floor higher at the back. To keep the flow under the floor away from the increasing boundary layer height. So then the aim is to keep the air moving and get it out from underneath as best as possible.

[newbie]

there is plenty of fun to be had in the upper floor area where those floor curls are, trust me on that one.