Red Bull RB18

[Stu]

The tunnels are far larger in cross-section than anyone else’s (as far as been seen).

[RGAEDA]

I wonder how much performance could be gained through that increased cross-section, probably not as much as it sounds but I think it's enough to compensate for the losses from the lower downforce rear wing.

[ing.]

The wooden plank skid marks seem as if the load of the car shifts throughout the lap but the most probable thing is that the car could be hitting the bumps on the tarmac at different speeds and different angles.

Silo, going with your theory, could it be that the low-pressure zone under the car, created by those deep tunnel shapes in the middle keeps RB18 away from porpoising? I remember Kyle's(KYLE.ENGINEERS) youtube channel has a video where he mentions the tunnel height contributing to porpoising, I think he said something like a taller tunnel has much fewer chances of detaching the airflow.

I was speaking about the juts in the main part of the floor, like Golameroso posted with the surfboard. At higher speeds I assume they are detaching the flow in some way, you might be right that they are disturbing the flow through the venturi to stop porpoising.

[ing.]

The wooden plank skid marks seem as if the load of the car shifts throughout the lap but the most probable thing is that the car could be hitting the bumps on the tarmac at different speeds and different angles.

Silo, going with your theory, could it be that the low-pressure zone under the car, created by those deep tunnel shapes in the middle keeps RB18 away from porpoising? I remember Kyle's(KYLE.ENGINEERS) youtube channel has a video where he mentions the tunnel height contributing to porpoising, I think he said something like a taller tunnel has much fewer chances of detaching the airflow.

Posted previously in the W13 thread:
Seems to me the roof of the RBR tunnels are very much arched in section whereas the Merc has a lower, wide and flat roof (in section) and also flat along a good portion of its chord.

The low, flat roof of the Merc would appear to make the flow more sensitive to ride height variations. At full bump, for example, the area will be reduced quite a bit more—assuming the width of the tunnels on both cars is similar. The Merc is turquoise and the RBR is purple:

https://i.imgur.com/MDt0t1K.jpg

With the Merc floor seeming to be flat along most of its chord ahead of the rear axle—as opposed to a more cambered wing-like profile—this would tend to make it more pitch and heave sensitive. As explained already by Migeot in the Autosport article, due to the cars having more suspension travel at the rear, heave displacement at full bump resembles a nose-down pitch attitude. With a flat floor, the throat moves aft and any blockage due to boundary layer build up would get exacerbated and so would affect total DF and CoP location. Front is —>

https://i.imgur.com/P8z35JL.jpg

This may explain why Merc have good numbers in the wind tunnel that don’t translate to results on track. Kind of like the extreme GE cars of the late ‘70s like the Lotus 80 and the Arrows A2.

[SiLo]

The wooden plank skid marks seem as if the load of the car shifts throughout the lap but the most probable thing is that the car could be hitting the bumps on the tarmac at different speeds and different angles.

Silo, going with your theory, could it be that the low-pressure zone under the car, created by those deep tunnel shapes in the middle keeps RB18 away from porpoising? I remember Kyle's(KYLE.ENGINEERS) youtube channel has a video where he mentions the tunnel height contributing to porpoising, I think he said something like a taller tunnel has much fewer chances of detaching the airflow.

I was speaking about the juts in the main part of the floor, like Golameroso posted with the surfboard. At higher speeds I assume they are detaching the flow in some way, you might be right that they are disturbing the flow through the venturi to stop porpoising.

Thanks! This is exactly what I was getting at.

[RGAEDA]

The wooden plank skid marks seem as if the load of the car shifts throughout the lap but the most probable thing is that the car could be hitting the bumps on the tarmac at different speeds and different angles.

Silo, going with your theory, could it be that the low-pressure zone under the car, created by those deep tunnel shapes in the middle keeps RB18 away from porpoising? I remember Kyle's(KYLE.ENGINEERS) youtube channel has a video where he mentions the tunnel height contributing to porpoising, I think he said something like a taller tunnel has much fewer chances of detaching the airflow.

Posted previously in the W13 thread:
Seems to me the roof of the RBR tunnels are very much arched in section whereas the Merc has a lower, wide and flat roof (in section) and also flat along a good portion of its chord.

The low, flat roof of the Merc would appear to make the flow more sensitive to ride height variations. At full bump, for example, the area will be reduced quite a bit more—assuming the width of the tunnels on both cars is similar. The Merc is turquoise and the RBR is purple:

https://i.imgur.com/MDt0t1K.jpg

With the Merc floor seeming to be flat along most of its chord ahead of the rear axle—as opposed to a more cambered wing-like profile—this would tend to make it more pitch and heave sensitive. As explained already by Migeot in the Autosport article, due to the cars having more suspension travel at the rear, heave displacement at full bump resembles a nose-down pitch attitude. With a flat floor, the throat moves aft and any blockage due to boundary layer build up would get exacerbated and so would affect total DF and CoP location. Front is —>

https://i.imgur.com/P8z35JL.jpg

This may explain why Merc have good numbers in the wind tunnel that don’t translate to results on track. Kind of like the extreme GE cars of the late ‘70s like the Lotus 80 and the Arrows A2.

Thanks, helps a bit to better understand the details.

[RGAEDA]

I was speaking about the juts in the main part of the floor, like Golameroso posted with the surfboard. At higher speeds I assume they are detaching the flow in some way, you might be right that they are disturbing the flow through the venturi to stop porpoising.

Thanks! This is exactly what I was getting at.

Thanks to you both, my understanding was very vague and I wasn't able to stick to one perspective. Now I'm clear about my thoughts.

[ing.]

As described in this article (sorry, in Italian) trying to understand what Ferrari, Red Bull and McLaren are doing with the steps at the back, upstream of the diffuser. Hard to see these steps created vortices—not sharp enough or oblique to the flow— so maybe they help drive flow to fill the diffuser.

https://it.motorsport.com/f1/news/f1-fe ... /10318576/

[AeroDynamic]

[organic]

Top Barcelona, bottom Baku




Mini floor stay present in Baku. Presumably due to the very high top speeds causing a problem for RB with floor flex

And possibly some different sculpting around the rear of the sidepod (though difficult to say concretely due to different angles/lighting). If you look at the edge of the floor it seems like it ramps up more gently in the Baku spec and finishes at a lower height, whereas Barcelona spec ramps more sharply from further rearwards, but again could just be the angle

Looks like the rear of the floor was lowered to create a more standard flatter section. This creates a more right-angled intersection with the sidepod and the internal floor stay now runs externally

[organic]

https://it.motorsport.com/f1/news/f1-re ... /10318898/

[organic]

Raising the floor there has created this pocket that maybe helps spool up a vortex down the channel that is evident:

[lucafo]

I notice this grill inside the cooling volume.
Maybe is this assumption correct?

[RZS10]

The apparently raised floor towards the center of the car is visible here:

New vs. Monaco

[organic]

Pretty big change IMO. We'd said at the beginning of the season in this thread that the low inboard floor was one of the starkest unique points of the RB18; guess we're seeing some convergence!