Red Bull RB18

[vorticism]

haha think i figured it out. This is their interpretation of the floor wing allowance. "Six support structures," and notice how many slats it has...

Bodywork declared as “Floor Edge Wing” must:
a. LiewithinRV-FLOOR-EDGE.
b. Beasinglevolumewithnoapertures.
c. Its complete surface, when intersected with any X-plane must produce only a single section that is continuous and closed, having cross-sectional area no greater than 2000mm2. This section must be between 5mm and 20mm distant from the curve produced by intersection of the Floor Body with the same X-plane, at its closest point.
d. Itscompletesurface,whenintersectedwithanyZ-planemustproduceonlyasingle section that is continuous and closed.
e. Itscompletesurfacemustbetangentcontinuousandanyconcaveradiusofcurvature must be greater than 25mm.
For the sole purpose of providing a structural connection between the Floor Edge Wing and the Floor Body, it is permitted to add up to six support brackets per side of the car. These brackets, which need not comply with parts (a) to (e), will nevertheless be considered part of the Floor Edge Wing and must:
f. Be in their entirety within 40mm of the Floor Body and 30mm of the Floor Edge Wing.
g. Benomorethan5mmthick.Afilletradiusnogreaterthan2mmwillbepermitted where these brackets join to the components they connect.
h. Benolargerthan40mmintheX-directionandhavenodimensionthatexceeds 60mm.
i. Not be closer than 50mm at any point to any other such support bracket.
j. Not be visible from below.

Whereas McLaren and others made a horizontal wing with six swans necks, RB made a vertical wing with six slots at its base. Brilliant.

[AR3-GP]

Could be a ride height limiter designed to rub the ground.

[godlameroso]

Red Bull's floor after FP1. A very unique bargeboard layout and well-refined diffusion tunnel as well. Are the silver strakes legal? The diffusion curve and CoP could probably be determined through these two images.

https://i.imgur.com/LGvSpN7.jpg

https://i.imgur.com/XhvP8YR.jpg

According to the CFD I've seen, the stronger you make the tunnel vortex, the greater the propensity of it to break down at the throat. So I'm guessing RBR saw that and tried to start the tunnel vortex as far down the length of the floor as possible, and widening the plank area to get more flow acceleration on the innermost strake. Also the strake shape positions the underfloor vortex with a straight shot at the diffuser. RB uses metal brackets instead of stays, not only is the flow cleaner, it also allows them to create a stronger air jet into the diffuser.

[vorticism]

Could be a ride height limiter designed to rub the ground.

For floor flex maybe. The plank will be the main ride height limiter.

[godlameroso]

So..
The inner most, largest vane stops quite short of the floor edge.
Its vortex sheds off the tip, exits the floor through the first U shape cutout, then immediately re-enters the floor at the second cut, joining up with a the vortex being shed from that rearward vane..
Possibly

The outer vanes create the vortex you mention, the two inner ones create the tunnel vortex, the rest of your assessment is largely correct.

[Mchamilton]

So..
The inner most, largest vane stops quite short of the floor edge.
Its vortex sheds off the tip, exits the floor through the first U shape cutout, then immediately re-enters the floor at the second cut, joining up with a the vortex being shed from that rearward vane..
Possibly

The outer vanes create the vortex you mention, the two inner ones create the tunnel vortex, the rest of your assessment is largely correct.

There must be a decent vortex shedding from the tip of the that inner most vane surely? Where it stops maybe 150mm short of the floor edge?

[godlameroso]

So..
The inner most, largest vane stops quite short of the floor edge.
Its vortex sheds off the tip, exits the floor through the first U shape cutout, then immediately re-enters the floor at the second cut, joining up with a the vortex being shed from that rearward vane..
Possibly

The outer vanes create the vortex you mention, the two inner ones create the tunnel vortex, the rest of your assessment is largely correct.

There must be a decent vortex shedding from the tip of the that inner most vane surely? Where it stops maybe 150mm short of the floor edge?

Because the car is travelling forward and at most a few degrees in yaw, that inner strake vortex will never leave the floor, nor would you want it to, it's helping the vortex that forms along the plank surfboard area. Remember that on the RB18 the floor inlet is sloped upward outboard vs inboard. This means the outer strakes receive more air mass to manipulate.



Extra air mass will create a stronger vortex along the floor, especially with the vortex that forms in the sidepod undercut, the two vortices work together.

[Vanja #66]

There must be a decent vortex shedding from the tip of the that inner most vane surely? Where it stops maybe 150mm short of the floor edge?

Vortex doesn't follow the geometry of the vortex generator. It goes with the flow, pun intended. Only the inner-most vane sheds a vortex that increases floor performance. Other vanes just help build-up the pressure between them.

[Mchamilton]

There must be a decent vortex shedding from the tip of the that inner most vane surely? Where it stops maybe 150mm short of the floor edge?

Vortex doesn't follow the geometry of the vortex generator. It goes with the flow, pun intended. Only the inner-most vane sheds a vortex that increases floor performance. Other vanes just help build-up the pressure between them.

https://i.ibb.co/ZdNqFWB/cp2-w13-closed-bottom.jpg

https://pic3.zhimg.com/80/v2-37a5c99e00 ... a_720w.jpg

Would it not shed off the tip of the vane at all then?

[Mchamilton]

There must be a decent vortex shedding from the tip of the that inner most vane surely? Where it stops maybe 150mm short of the floor edge?

Vortex doesn't follow the geometry of the vortex generator. It goes with the flow, pun intended. Only the inner-most vane sheds a vortex that increases floor performance. Other vanes just help build-up the pressure between them.

https://i.ibb.co/ZdNqFWB/cp2-w13-closed-bottom.jpg

https://pic3.zhimg.com/80/v2-37a5c99e00 ... a_720w.jpg

If this site wasnt such a pain to add pictures to id make an illustration of what i was thinking lol

[Vanja #66]

Would it not shed off the tip of the vane at all then?

No, the highest pressure is formed where the convex curve is and this air then starts to spill. Once it starts spilling, the pressure is lower, but the low-pressure vortex core is now sucking the air towards it and it keeps spinning. Vortices break up when the flow is disturbed enough to cut-off the airflow towards the core, which doesn't usually happen with race cars since their VGs are very potent.

[godlameroso]

There must be a decent vortex shedding from the tip of the that inner most vane surely? Where it stops maybe 150mm short of the floor edge?

Vortex doesn't follow the geometry of the vortex generator. It goes with the flow, pun intended. Only the inner-most vane sheds a vortex that increases floor performance. Other vanes just help build-up the pressure between them.

https://i.ibb.co/ZdNqFWB/cp2-w13-closed-bottom.jpg

https://pic3.zhimg.com/80/v2-37a5c99e00 ... a_720w.jpg

Would it not shed off the tip of the vane at all then?

A little helper one, but the main vortex happens at around 70% of the airfoil wingspan, at least if they're doing what I think they are.

[chrisc90]

Are all the little wires and boxes sensors to measure what the airflow underneath is doing?

[PlatinumZealot]

haha think i figured it out. This is their interpretation of the floor wing allowance. "Six support structures," and notice how many slats it has...

Bodywork declared as “Floor Edge Wing” must:
a. LiewithinRV-FLOOR-EDGE.
b. Beasinglevolumewithnoapertures.
c. Its complete surface, when intersected with any X-plane must produce only a single section that is continuous and closed, having cross-sectional area no greater than 2000mm2. This section must be between 5mm and 20mm distant from the curve produced by intersection of the Floor Body with the same X-plane, at its closest point.
d. Itscompletesurface,whenintersectedwithanyZ-planemustproduceonlyasingle section that is continuous and closed.
e. Itscompletesurfacemustbetangentcontinuousandanyconcaveradiusofcurvature must be greater than 25mm.
For the sole purpose of providing a structural connection between the Floor Edge Wing and the Floor Body, it is permitted to add up to six support brackets per side of the car. These brackets, which need not comply with parts (a) to (e), will nevertheless be considered part of the Floor Edge Wing and must:
f. Be in their entirety within 40mm of the Floor Body and 30mm of the Floor Edge Wing.
g. Benomorethan5mmthick.Afilletradiusnogreaterthan2mmwillbepermitted where these brackets join to the components they connect.
h. Benolargerthan40mmintheX-directionandhavenodimensionthatexceeds 60mm.
i. Not be closer than 50mm at any point to any other such support bracket.
j. Not be visible from below.

Whereas McLaren and others made a horizontal wing with six swans necks, RB made a vertical wing with six slots at its base. Brilliant.

So they are using the allowed supporting brackets as giant vanes and putting them underneath the floor and the brackets need not comply with sections a) to e).

Hmm. The problem with this however is that the other teams will argue that the brackets need not be so large for the "sole purpose" of supporting the edge wings!

[Mchamilton]

Would it not shed off the tip of the vane at all then?

No, the highest pressure is formed where the convex curve is and this air then starts to spill. Once it starts spilling, the pressure is lower, but the low-pressure vortex core is now sucking the air towards it and it keeps spinning. Vortices break up when the flow is disturbed enough to cut-off the airflow towards the core, which doesn't usually happen with race cars since their VGs are very potent.

Comparing the images of the RB and Merc floors. The merc looks to have a completely flat tunnel roof whereas the RB looks like it has a convex roof through the throat area.
Would the convex roof be better for maintaining more stable vortices?