Red Bull RB7 Renault

[PlatinumZealot]

Funny how the dye is not burnt. Might be a clue to how wide the exhaust stream is.

[wesley123]

Imo the exhaust gasses do not even enter the diffuser, they seal off the floor with the higher rake, causing a much bigger diffuser then it really is.

[PlatinumZealot]

I disagree there. I can safely report though, that The Mclaren employees call RBR's diffuser a "Blown in" Diffuser.

[Callum]

Foam in the wing pillars?

[JackHammer]

It's in the rear wing endplates too

[wesley123]

I disagree there. I can safely report though, that The Mclaren employees call RBR's diffuser a "Blown in" Diffuser.

But how would this even blow in the diffuser? I mean, there is no hole in the sidewall, it would have to flow in from the bottom, still pretty much doing the same. I am pretty much convinced by myself that this EBD plus high rake just causes one huge diffuser.

[BreezyRacer]

I disagree there. I can safely report though, that The Mclaren employees call RBR's diffuser a "Blown in" Diffuser.

But how would this even blow in the diffuser? I mean, there is no hole in the sidewall, it would have to flow in from the bottom, still pretty much doing the same. I am pretty much convinced by myself that this EBD plus high rake just causes one huge diffuser.

There is, exactly a hole in the floor next to the diffuser in the inner wheel area. That is what they use and the shape of it has been copied by others as it appears that the shape helps to vortex the exhaust under the floor.

For my money the exhaust flow is isolating the tire turbulence from the diffuser box, which is a big issue with diffuser effectiveness. Also a rather new addition to the RB diffuser is the slotted gurney and the curved up exit lip, giving something of a wing trailing edge to the back of the diffuser box. Do not discount it's importance as it keeps diffuser flow attached to the diffuser during pitch changes, etc. Newey didn't originate it but he sure has refined it.

[Full_Opposite_Lock]

I have a few questions on diffusers and ride height

1. Can anybody tell me how significantly ride height affects diffuser performance?

2. How does the large rake of the red bull affect this?

3. When the DRS is enabled, does the decrease in downforce significantly increase ride height, and would the effect be larger on a higher raked car such as the red bull?

[hardingfv32]

1) I also thought that the exhaust was used for sealing the diffuser, but there is the now customary white insulating material on the inside of the diffuser and not on the outside. This can be seen in the above photos. To me this implies that most of the flow curls under into the inside of the diffuser. Now that is not to say there wouldn't be some sealing benefit from this flow arrangement.

2) Wouldn't foam between the outer skins be considered standard laminating practice?

Brian

[wesley123]

I disagree there. I can safely report though, that The Mclaren employees call RBR's diffuser a "Blown in" Diffuser.

But how would this even blow in the diffuser? I mean, there is no hole in the sidewall, it would have to flow in from the bottom, still pretty much doing the same. I am pretty much convinced by myself that this EBD plus high rake just causes one huge diffuser.

There is, exactly a hole in the floor next to the diffuser in the inner wheel area. That is what they use and the shape of it has been copied by others as it appears that the shape helps to vortex the exhaust under the floor.

For my money the exhaust flow is isolating the tire turbulence from the diffuser box, which is a big issue with diffuser effectiveness. Also a rather new addition to the RB diffuser is the slotted gurney and the curved up exit lip, giving something of a wing trailing edge to the back of the diffuser box. Do not discount it's importance as it keeps diffuser flow attached to the diffuser during pitch changes, etc. Newey didn't originate it but he sure has refined it.

Ahh, thanks for the clarification!

[BreezyRacer]

I have a few questions on diffusers and ride height

1. Can anybody tell me how significantly ride height affects diffuser performance?

2. How does the large rake of the red bull affect this?

3. When the DRS is enabled, does the decrease in downforce significantly increase ride height, and would the effect be larger on a higher raked car such as the red bull?

Any designer with the tools (wind tunnels and CFD) is going to design the diffuser to work in a range of pitch and yaw that the car is likely to see. In general the higher the ride height the more diffuser angle the car needs to work, but that's ride height changes of inches, not millimeters like an F1 car. The rake of the RB has been designed in so it's part of the overall package and thus, any effect it causes has been dealt with.

[djos]

Imo the exhaust gasses do not even enter the diffuser, they seal off the floor with the higher rake, causing a much bigger diffuser then it really is.

I agree and postulated that very idea in this thread ages ago but no one seemed to notice.

[hardingfv32]

Then why does the diffuser have the inner surfaces of the end plates protected with heat insulation?

Brian

[Nickel]

Imo the exhaust gasses do not even enter the diffuser, they seal off the floor with the higher rake, causing a much bigger diffuser then it really is.

I agree and postulated that very idea in this thread ages ago but no one seemed to notice.

This idea seems to make a fair bit of sense in my mind. Someone else mentioned isolating dirty flow from the tires. Perhaps the earlier comment regarding Mclaren refering to it as a "blown in" diffuser is similar to saying "fenced in".

Then why does the diffuser have the inner surfaces of the end plates protected with heat insulation?

I would (without real reason...) assume that even if the flow was designed to fence in the diffuser, that you would get some spilage for lack of a better word. Perhaps by design or by necessity, the gasses are probably not limited to the boundary between the tires and the diffuser. Remember as well that for Newey, this is the best spot allowed in the rules, not the absolute best spot. Perhaps it does both? As in fences of the diffuser, and gives energy to the outside of the diffuser?

[djos]

Then why does the diffuser have the inner surfaces of the end plates protected with heat insulation?

Brian

To protect the Carbon from heat-soak which will damage it.