[Closed] Any aerodynamicists out there?

I think you're right. But then I'm not skilled in anyway in this respect past A level. And we didn't do F1 cars driving up walls in Physics then, sadly.

[Tannoy]Coffeeking to the forum please[/Tannoy]

Me too, shame isnt it, that would have been much more fun to do as an experiment ...

If STW fails me then I will try McLaren & see if they can answer it.

Yes, it's probably theoretically possible with a suitable 'road'.

btw, there's no issue with top speed - the car doesn't need to keep accelerating. So long as it has sufficient power to work against gravity + wind resistance at a sufficient speed to generate enough downforce to give sufficient grip for the power.....

I can't be bothered to do the sums though.

They might generate over 1G of acceleration on the flat where they are "only" working against wind resistance and friction, its a very different matter accelerating that hard going vertically upwards when already doing 100mph...

It is possible to calculate but I CBA! Interested in Mclaren's response

I have sent the question to them & will update when I have it

Is there a conveyor belt on the wall?

Have you been watching Batman?

M.I.B.

ok, so it's got enough 'downforce' to stick to the wall at 100mph.

the question is, does it have enough spare power to lift itself vertically at 100mph.

(envelope engineering - begin)

assume it's got a max of 800hp = 600KW.

at 100mph it's got 2/3rds spare power = 400KW

can 400KW lift a 500kg car at 100mph?

100mph = about 40m/s

power = mass*gravity*speed

power = 500*10*40

power = 200000 Watts = 200KW

yes, it's got enough power spare.

i'm sure i've cocked that up, but i'm a bit busy, can someone check it for me?

ah 25000Watts = 250kw, so in theory yes?

What they did in MIB would work 🙂

And yes it could drive up a wall. Doesn't need to be accelerating either. Question is is there enough power to keep it going upwards at sufficient speed?

F = m * a
P = F * speed

So say it needs to do 150mph to generate enough downforce, for it to be sustainable, 900hp (or whatever the car can generate) needs to be more than the product of the mass of the car (500kg?), 9.8m/s/s and 150mph.

Assuming the tyres can provide that much traction, which I guess they would.

EDIT: oh yeah ahwiles, the drag incurred in generating the down(side?)force would rob some power of course... didn't take that into account 🙂

M.I.B.

But they went upsidedown in MIB. IN Batman he went up the wall like the OP question 😉

And in my layman mentality the theory should be identical - the downforce would work in an identical way wouldn't it?

if an F1 car can drive up a wall, I want to see up wall race tracks invented. You'd have to do some sort of crazy corkscrew arrangement to get them back down on the ground but I'd start watching F1 again, for sure.

Wouldn't you need to consider positions of centre of mass & centre of downforce as well as the moment from the torque of the wheels as well - they'd need to balanced to stop it peeling away from the wall. For instance if you try to push a toy car up the wall with your finger pressing on the back wheels it won't work, and pressing harder just makes it worse. Not that I've been mucking about with toy cars when I should be working, oh no.

if an F1 car can drive up a wall, I want to see up wall race tracks invented. You'd have to do some sort of crazy corkscrew arrangement to get them back down on the ground but I'd start watching F1 again, for sure.

It'd be like Wipeout on the playstation. The sooner I see a race track spiralling through the centre of a gigantic shopping mall, the happier I'll be.

As for downforce distribution - they already fiddle with this all day so it'd be pretty easy to sort out.

What happens when you reach the top of the wall?

could you put it in a 100mph wind tunnel, with its nose tied to the fan end of the tunnel so it isnt blown away, and then just, "stick it on the wall"?

maybe if you put a conveyor belt vertically the car would never run out of wall?

if an F1 car can drive up a wall, I want to see up wall race tracks invented

maybe if you put a conveyor belt vertically the car would never run out of wall?

Surely if the velocity vector is exactly in the opposite direction to the direction of the force due to gravity, and both are in the plane of the wall, then only minimal "downforce" is required to keep the car attached to the wall?
So if it had enough speed, drove up a ramp on to the wall, it could coast up the wall until apogee.
Ignoring the sums about power etc., and assuming it's true that the car's power allows it to overcome the pull of gravity, drag etc., does the 1G less in "downforce" allow the car to put that power down, or will the wheels just spin?

Of course it works - look - even kids know how to do it...
[img] [/img]

Sorry guys (geoffj especially, for his noticing I'm an engineering geek 😆 ), aerodynamics isn't my field so I'd be making the same ballpark figure guesses that anyone else would. Looking at the fact that it's well known that they could drive upside down at ~70mph and they have more than enough power to lift their weight vertically at that speed, including drag, I'd say yup, almost undoubtedly.

Getting them TO that speed would require a nice transition though, maintaining speed without bottoming out the suspension, and they certainly couldn't accelerate from standing vertically obviously.

I didnt ask McLaren about converor belts, think I should?

My sons original question was would an F1 car be able to drive up a road to the moon, I initially said no, it would run out of fuel .... but I guess actually it wouldnt, the atmosphere ends not that far away so next years cars should be able to make it then it just needs clever people who can work the trajectory ... my head hurts now.

The acceleration required to leave the earth gravitational field is a lot bigger, so that's a very different problem.

F1 car on a wall or inverted is fine though. There's no reason why it could corner too - to turn and come back down. It'd be more of a problem if you crashed or had a mechanical, it'd be a long drop. Driver ejector seats and parachutes maybe?

Dont forget that as you leave the dense atmosphere you'll lose downforce and not be able to grip the wall anymore, so effectively you'd need a very big ramp. And you'd need to get the car to approximately 26,000mph (escape velocity) before the end of the ramp.

My sons original question was would an F1 car be able to drive up a road to the moon, I initially said no, it would run out of fuel .... but I guess actually it wouldnt, the atmosphere ends not that far away so next years cars should be able to make it

I might have missed the point here but I thought that internal combustion engines used a mixture of fuel and air so without an atmosphere they might struggle rather...

I thought F1 was fuelled exclusively by the hot air Bernie Ecclestone blows and by virtue an F1 car would, therefore, run anywhere Bernie struts all 4ft 2in of his frame...

Simple solution... Bottles of air. or a very big scoop to cram a lot of that thin air into the engine. Of course, that could add a bit to weight and drag, so you might need a bigger engine.

i think we've just witnessed a STW miracle; i think we're all agreed on something...

if a modern F1 car CAN drive up vertical walls, or upside down, then surely new F1 tracks should be built to take advantage of this.

surely? anything else is cowardice.

you could build a track with barrel-roll / cork-screw short cuts with the option of a time consuming horizontal chicken run for the cowards.

(the back-flip has become a 'standard' trick in FMX, the F1 boys need to catch up quickly if they want me to start paying attention)

I always thought that they should turn the tunnel at monaco into a sort of laid on its side half pipe, giving a nice curved transition onto the wall and then the roof, allowing upsidedown overtaking and such.

I assume the downsides would be mechanical failures while inverted, and drivers not getting back down fast enough, and firing themselves into the harbour upside down.

be good to watch/would make a cooler demo for one of the teams than arsing about around the streets of london as they seem to occasionally.

Dan

Soooooo, I have heard back from McLaren, the odd thing is that STW (& I) appear to be wrong

Dear Geoff,

This is a very interesting question and one we have never been asked before, although people have talked for years about the possibility of F1 cars running upside down in a tunnel, which is possible, so going vertically up a wall took a bit of thinking about!

Unfortunately, it is not possible and the reason is that the engine is not quite powerful enough to drive the car quick enough to generate the down force that is necessary to produce the traction that is needed at the rear tyres, given that the engine has also got to overcome gravity on top of everything else, but it could go up at slope at 85 degrees.

I hope this answers your question,

Kind regards

McLaren Racing Limited

Can you just ask if it could do it for 6 or so seconds with the KERS deployed?
🙂

Excelent! I like the fact they've calculated what angle it could go up.

Fantastic answer there.

I suspect they could tell that Ferrari could manage 83 degrees & the Renault about 53 🙂

[i]heard back from McLaren, the odd thing is that STW (& I) appear to be wrong [/i]

Nope. McLaren are wrong. STW are *never* wrong.

Going vertical would also affect fuelling and oil levels on the car so it could stop rather quickly...I think it was Bugatti that changed the angle of their oil channels as they discovered they started loosing power when they turned right...the force caused by the speed of the turn meant the oil was not reaching where it was needed and was robbing the engine of power...so they changed the angle to slow the reduced flow and discovered the power wasn't so bad when cornering...

Or thereabouts, I forget all the actual detauils but that is pretty much it in a nutshell...

Itr would be cool to see though...a car driving up a wall...or indeed driving upside down on the roof of a tunnel.

STW were wrong due to incorrect power assumptions, we worked on the old figure of ~900hp, current engines are apparently only good for ~750hp. 😆 Gutted, mis-information leading the way - that'll be a first in STW 🙂

I'd be fascinated to see their calcs actually.

Good on McLaren for answering.

I have managed to get tickets to their event at Brooklands on 8th Nov as well 🙂 we are very pro McLaren in our house now

they're still cowards.

(and i don't buy their answer that they don't have the down-force to produce enough grip against the wall

the sine of 85 degrees is 0.996, which means they only need to find 0.4% more grip)

(disclaimer; all my calculations are done with a scrap of paper, my phone, and about 30seconds scribbling)

willard - Member

Simple solution... Bottles of air. or a very big scoop to cram a lot of that thin air into the engine. Of course, that could add a bit to weight and drag, so you might need a bigger engine.

A bigger engine would need more air....

A turbo/supercharger is what you want 😉

But that'd still only work to a certain altitude.

It's threads like this that are what I love about STW. Well done chaps. 8)

85 degrees is pretty damned close to 90, but remember relationships between downdforce, power and grip are not linear, they're likely to be squares off the top of my head. Obviously a lot more power is eaten up in generating downforce than seems intuitive.

A bigger engine would need more air....

A turbo/supercharger is what you want

A small engine with a turbo needs more air too. In fact a 1 litre engine boosted to 1 bar needs approximately the same air as a 2 litre engine (though it is a lot lighter).

Top thread - and Top Marks to McLaren for coming back to you - bet they had a fun few minutes over morning coffee doing the workings on that. 😀

Yeh, I was pretty pleased that they came back & that we had come up with something they hadnt been asked before... & burning up their computer time to check it 🙂