Aerodynamic implications of nose inlets

[Adrian Newby]

Excellent rough and dirty effort with the CFD. I do think the Caterham/Lotus type nose will give the best drag numbers with that kind of analysis. Did you include the RB8's side fences on your CFD analysis? I think that would improve the spillage greatly, and increase the flow into the intake.

Yes I had the side fences. When I say Rough and dirty I mean:

I had rolling road
5 refinement levels (very good actually)
No spining wheels
Just ball park surface roughness and turbulence levels
I had gravity effects
No driver

There might be other effects that propagate backwards, but I am no expert.

Wow, I think you are selling yourself short calling it "rough and dirty" then!

I am very surprised that the fences didn't result in less side spill than your results showed.

I wonder if Newey might have the exit flowing into an area of faster moving air to create a suction on the intake?

[Adrian Newby]

Apparently it is quite a chore to cool the KERS and still achieve Adrian Newey's aero packaging concerns, since it over heated so much last year. The only potential problem I could see with the ducting, if getting cooling flow from the nose, is connecting the upper duct to the lower one. The most room for that would probably be on the sides, in the ankle area.

Is the chassis's exterior dimensions pretty much controlled by the internal cross section specification or rule? If so, are they going widen the chassis to provide space for the very inefficient ducting being proposed? I think not. They want the chassis as narrow as possible.

Brian

There is no way they would widen the chassis for... pretty much anything. But since the chassis has more of a square cross-section, and the driver's seat is more rounded, there should be fairly good-sized triangle area in the lower corners to get past the seat, and that would be the tightest area.

[Adrian Newby]

We should also remember that the F-ducts started with an intake in the nose and ran all the way to the rear wing, so getting a duct to just behind the seat shouldn't be impossible.

[hardingfv32]

But since the chassis has more of a square cross-section, and the driver's seat is more rounded, there should be fairly good-sized triangle area in the lower corners to get past the seat, and that would be the tightest area.

The interior has a required square section that looks very similar to the current chassis exteriors section. Only the steer wheel and padding can encroach into this area. There are no triangle free areas.

Brian

[bhall]

We should also remember that the F-ducts started with an intake in the nose and ran all the way to the rear wing, so getting a duct to just behind the seat shouldn't be impossible.

Agreed, it's definitely possible. But, with the abundance of better solutions available, why?

(I can't remember on which car I saw this, but (I think) one of them has a small vent in the splitter underneath the car. I thought of that while brainstorming alternate solutions for RB8, and then it dawned on me that the splitter would be an excellent place to house the KERS batteries. It's slightly forward, very low and it means you don't have to sacrifice CG by placing it under the fuel tank. It's an idea so obvious, it's probably not even new; I just haven't seen it mentioned yet.)

[marekk]

There were no steps on the noses in the past, hence no big spillage to manage

1) There is always spillage off the top surface of the front of the car. I can agree that the step causes more, but why allow ANY if spillage is truly a negative? Is this not logical?

2) Why does Ferrari not have fences at their step? Would it not be simple to CFD or test in the wind tunnel? If you guys can dream up such thesis, would not paid professional also be able to see the possibilities?

Brian

Why do you think there is ANY spillage off the top surface of the front of the car to the sides?
I would rather expect the (very valuable) air from the sides to escape to the top of the car - i can't see anything in this area to force incoming flows sideways except for pressure differences, and at least beginning with the tub, the chassis becomes wider much quicker then higher, so pressure should build up quicker on the sides then on the top.

[Adrian Newby]

But since the chassis has more of a square cross-section, and the driver's seat is more rounded, there should be fairly good-sized triangle area in the lower corners to get past the seat, and that would be the tightest area.

The interior has a required square section that looks very similar to the current chassis exteriors section. Only the steer wheel and padding can encroach into this area. There are no triangle free areas.

Brian

How did they run the F-duct through the chassis then, if nothing else can encroach the cockpit area?

And to answer your earlier question, yes, I have owned, and driven (obviously smaller than F1) open-wheel formula cars, and - at least on those cars - those triangle areas are where we ran everything that needed to go from the cockpit to the rear end. Unless you have a square butt or a rounded chassis bottom, there will be triangle areas there.

[Adrian Newby]

We should also remember that the F-ducts started with an intake in the nose and ran all the way to the rear wing, so getting a duct to just behind the seat shouldn't be impossible.

Agreed, it's definitely possible. But, with the abundance of better solutions available, why?

(I can't remember on which car I saw this, but (I think) one of them has a small vent in the splitter underneath the car. I thought of that while brainstorming alternate solutions for RB8, and then it dawned on me that the splitter would be an excellent place to house the KERS batteries. It's slightly forward, very low and it means you don't have to sacrifice CG by placing it under the fuel tank. It's an idea so obvious, it's probably not even new; I just haven't seen it mentioned yet.)

I just don't believe the ducting is as big an issue as other people do. For the size of that slot, a small duct could even run behind the dead pedal (if the RB8 has one, it looks like the RB6 did), and into the duct on the bottom that is already there (which would need to be enlarged a bit). And small ducts for cooling are generally a drag write off anyway, once they have done their duty. I think Newey saw that he would have this new hump to deal with, so he tried to turn it into a positive in as many ways as he could.

[bhall]

I'm not at all doubting the plausibility. But, no matter how simple it would be to accomplish KERS/whatever cooling through the step of the nose, there are other areas of the car where placement of a cooling duct would be even easier and make for a more effective solution.

Adding to my belief that said duct has another purpose is an interview I read recently - but can't remember where - in which Newey said there are some aesthetic reasons behind the installation of the duct. That immediately raised a red flag in my mind, because I think there's simply no way a disciplined engineer like Adrian Newey allows form to enter the equation.

I'll concede that my notion could very well turn out to be false logic, but it's the only bit of logic I have right now. (I think?)

[hardingfv32]

Why do you think there is ANY spillage off the top surface of the front of the car to the sides?

You are not following the context of the tread. It is being proposed that the RB nose step vent reduces spillage. I am questioning that premise.

How did they run the F-duct through the chassis then, if nothing else can encroach the cockpit area?

They would have had to make the chassis wider if using the current rule set (13.3.1 & 13.3.2) or run it outside the chassis, which I think was the common solution.

Note: The ducted air flow through or beside the chassis was part of the control circuit and not the main flow source.

Brian

[hardingfv32]

at least on those cars - those triangle areas are where we ran everything that needed to go from the cockpit to the rear end.Unless you have a square butt or a rounded chassis bottom, there will be triangle areas there.

At your race meetings, have you ever seen an example of a duct running a long and contorted path similar to what you are proposing... No. That is in any class. You still are not accounting for the fact that the duct must expand in size as it travels back or how the exhaust, many times larger cross section, finds a way to a low pressure area.

Brian

[hardingfv32]

the splitter would be an excellent place to house the KERS batteries. It's slightly forward, very low and it means you don't have to sacrifice CG by placing it under the fuel tank. It's an idea so obvious, it's probably not even new; I just haven't seen it mentioned yet.)

Are you willing to live with the weight of the power cables? The teams don't see to be. The current trend is to put everything together in front of the engine and below the fuel cell, greatly reducing cabling.

Brian

[bhall]

I wasn't really suggesting that to suggest it. It was just an aside to my larger point that I don't think Red Bull is cooling KERS, or anything else, with the duct on the stepped nose.

But, since you asked: it depends on the size of the batteries and their effect on the dimensions of the fuel tank. And it probably makes more sense in a formula that doesn't specify overall weight distribution. Otherwise, the placement is ideal, and if it can be more efficiently cooled, such as with a duct on the splitter, I think it would give engineers some leeway with the overall design of the KERS; it could possibly be more extreme in terms of size or how it accepts a charge.

[hardingfv32]

placement is ideal, and if it can be more efficiently cooled, such as with a duct on the splitter

And the batteries will love the hammering they take going over the curbs.

Brian

[bhall]

No more or less than anything else that gets jarred to holy hell throughout the course of a race.


(FYI: You don't have to disguise as questions any statements you wish to make; you can just say whatever it is you want to say. I know you didn't just do it. I've simply chosen this time to say something.)