Idea for a little extra aero efficiency..

[Craigy]

Hello all,
I wonder if anyone can help me - I was looking for info on whether it would be within the rules to do the following:

1. make existing engine radiators smaller
2. route a coolant system around the rear wing, making up for cooling lost in (1)
3. make sidepods slightly smaller

Would the pipework around the rear wing be legal?
I'm assuming here that you could change a material or two to turn it into a large radiator fin - for example, a thin foil of something conductive on the upper/lower/sides of the carbon.

Clearly there would be an aero impact on the rear wing design if you have to include space for the coolant to run through, so I'm not thinking here about a round piece of pipework. Think about the space inside an aerofoil cross-section - that's the sort of "pipe" I'm thinking of.

Is that legal?

Also - would it be worthwhile?
Would the impact of more weight high up in a "rear-wing-rad" be useful compared to the gains from a smaller sidepod?

What do you think?

Craigy

[CMSMJ1]

Water is heavy and you want it as close to CoG as possible for handling purposes.

Routing a lot of heavy pipework and a heavy finned wing would not make sense...

[Craigy]

Water is heavy and you want it as close to CoG as possible for handling purposes.

Routing a lot of heavy pipework and a heavy finned wing would not make sense...

Yep, understood but as often mentioned, aero efficiency is king on an F1 car.

The whole cooling system (glycol, I think) on a current F1 car is currently no more than a few litres - we are talking about an additional cooling circuit that could probably be done within a budget of about 2 or 3 litres, I think (bearing in mind the sort of pipework I was talking about). The rear wing isn't made of one-piece of carbon as it stands, it's made of layers anyway, so we're really talking about making something a little wider (3mm?).

My questions really come down to: is this a compromise too far?
Your answer is pretty clearly "no" based on a mechanical viewpoint, which is fair enough.
Would any other people choose to answer? - I'd love to know how much smaller the rads could be made if we could dump about 10% of the coolant heat out of the rear wing. (Bearing in mind it's in cool airflow and isn't enclosed, I doubt this is impossible).

C

[Sawtooth-spike]

Surely by making the rear wing the rear wing a heat exchanger you will be Warming it up quite abit. Surely this would have some effect on the air that is moved over it.

I Would also agree the added weight and issues to getting it all hook up, would out weigh the Aero gain from smaller sidepods. Also You would need more pumping power due to the extra length, also you would have to lift the coolent up into the rear wing. So a bigger pump would be needed. I am not 100% sure but i am guessing that the pump is run from the engine, so this would reduce overall power.

[marcush.]

the idea of using the outer skin of the car as a means of surface cooling was
showed on one off Gordon Murray s Brabhams- 1978-? it was the same year they had the famous blower car in Anderstorp.
Unfortunatelly the whole idea did not work as the surface simply was too small for the efficiency those surface heat exchangers had ,if they actually tested the idea
with the car on track ?

[CMSMJ1]

I do not know for sure - but I would say the cooling system uses more than a few litres and that is water rather than glycol.
My race bike has 3 litres of water to cool a dinky 65bhp motor...I reckon that a 700+ bhp engine needs more than that under some decent pressure to get the heat away.

It is not the worst idea but why not have the floor of the car or the top of the sidepods as the surface area. The plumbing, pumps and what not would make, in my opinon, the rearward biased location for it untenable.

Ref the Brabham - has anyone seen any pics or details other tha the grainy B+W shot you can google for? I have read, on here, that this was a white elephant and never used.

[Craigy]

the idea of using the outer skin of the car as a means of surface cooling was
showed on one off Gordon Murray s Brabhams- 1978-? it was the same year they had the famous blower car in Anderstorp.
Unfortunatelly the whole idea did not work as the surface simply was too small for the efficiency those surface heat exchangers had ,if they actually tested the idea
with the car on track ?

I'm not suggesting all the cooling comes from the wing, just some. The rear wing is pretty exposed, and everything behind it is not something we care about being hot, so it seems a decent place to dump heat.

In addition, in the 1970's the focus wasn't on chasing 0.1s; it was on the best place to gain 1s or 2s per lap. We're in a very tightly rigid set of rules now, so very small incremental improvements may be worthwhile...

C

[Craigy]

I do not know for sure - but I would say the cooling system uses more than a few litres and that is water rather than glycol.

I'm pretty sure I saw green fluid leaking out of a crashed F1 car's radiators a few years ago, so they may have changed that (I'm pretty sure it was a Mclaren). On the subject of "a few litres" I suppose it depends on your definition of "a few".

My race bike has 3 litres of water to cool a dinky 65bhp motor...I reckon that a 700+ bhp engine needs more than that under some decent pressure to get the heat away.

10% of the cooling on a 740bhp engine may well be similar to the sort of thing you're talking about - if you are willing to assume that we are cooling "74bhp worth of engine". The amount of coolant volume used isn't far from what I mentioned either.

It is not the worst idea but why not have the floor of the car or the top of the sidepods as the surface area.

I'd suggest the wing is better purely in terms of heat exchange because there are parts of the car behind that which we'd like to keep cool. My idea, on the other hand, dumps heat out of the back edge of the car. Also - the air hitting the wing in the first place won't have been worked as hard as the air going in the sidepods. It's likely to be more effective on the rear wing than on a body part for that reason. Whether you can transfer enough heat out of a relatively small surface area to make the system worthwhile is another question...

The plumbing, pumps and what not would make, in my opinon, the rearward biased location for it untenable.

My thinking here is that there's already pipework in the chassis for the gearbox cooling - maybe you could route the water to do this job too (not 100% sure of temps but gearbox oil is bound to be hotter than engine coolant, I recon). Yes, there would be more complexity, but since when were F1 teams bothered by that?
I don't think you'd have to change the coolant pump much. There may even be an optimisation that allows the source hot water to come from the back of the engine block itself - this would miss out a bit of work and also cause other work. I suppose it also depends on the direction the cooling system already pumps coolant - cool in the top, or cool in the bottom, etc.

C

[Craigy]

...You would need more pumping power due to the extra length, also you would have to lift the coolent up into the rear wing. So a bigger pump would be needed. I am not 100% sure but i am guessing that the pump is run from the engine, so this would reduce overall power.

Have a read of http://www.f1technical.net/features/250

According to that, F1 cooling systems run about 3.75 bar of pressure (about 54psi for the SI-inhibited). That's easily enough to get a couple of litres of water to rise 50cm, go through a pipe, and come back again.

I'd be interested to know what the cooling effectiveness of a rear-wing-rad would be like at 300kph. Perhaps you could set up a valve to divert water to whichever sort of rad was returning the coolest coolant... (the "normal" rads would be far more effective at slower speeds than the rear wing one, I think.)

Imagine the cooling properties of a rad-wing at 190mph. It may be worthwhile, at least in places like Monza.

C

[CMSMJ1]

Water is heavy and you want it as close to CoG as possible for handling purposes.

Routing a lot of heavy pipework and a heavy finned wing would not make sense...

Yep, understood but as often mentioned, aero efficiency is king on an F1 car.

The whole cooling system (glycol, I think) on a current F1 car is currently no more than a few litres - C

You said a few litres...not me!

I've seen the size of the F1 rads - they are bloody big pieces of kit and must hold at least 7 litres.

Pretty much all racing regs I have ever seen stipulate water and no additives for coolant as anything else is too slippy in case of a spill.

I don't mean to be a spoilsport but if there was a benefit, especially aero, for this idea we would see it more often.

Think back to the old school - you would see gearbox oil coolers mounted in the air flow on the bellhousing.

In fact, get a look at some pics of Phoenix 1989 - the McLarens ran an addtional cooling rad on the right hand side of the car above the sidepod and beneath the rear wing. That was the last time I saw anyone do something as aero bad as that for cooling reasons.

Another point (ref having a valve to switch flow) is that, AFAIK, the hotter you can run then the smaller you can have your rads. SO, you would want to keep your rads as small and as close to source as possible to maximise the heat transfer to the cool air coming in the sidepod. The air over the rear wing will be hotter than front facing pods...

The more I think about it the more downsides I can see...I guess you are the opposite!

Such a cool site this one =D>

[marcush.]

for what reason you would want to run glycol? sudden ice in Brasil?
absolutely no way they have glycol in the water system.
what they have is something to lubricate the pump and something to avoid corrosion
in the system..

[Sawtooth-spike]

...You would need more pumping power due to the extra length, also you would have to lift the coolent up into the rear wing. So a bigger pump would be needed. I am not 100% sure but i am guessing that the pump is run from the engine, so this would reduce overall power.

Have a read of http://www.f1technical.net/features/250

According to that, F1 cooling systems run about 3.75 bar of pressure (about 54psi for the SI-inhibited). That's easily enough to get a couple of litres of water to rise 50cm, go through a pipe, and come back again.

Yes it could but would it do it fast enough?

For it to work you would need to hold a some coolent in the rear wing, which is high up and is still a weight in totaly the wrong place. There is no point where you would ever want to put weight high up in and f1 car unless you had too.

I like the concept really i do. But i cant see how the trade off would be worth it

[bri]

A good reason for adding Ethylene Glycol to a cooling system is because it raises the boiling point of water. 30% of glycol raises the boiling point to 104.4 C. As mentioned in a earlier post the hotter the coolant the greater the radiator efficiency ,plus less chance your F1 car sits on the grid doing an impersonation of a Stanley Steamer.

[Craigy]

absolutely no way they have glycol in the water system.
what they have is something to lubricate the pump and something to avoid corrosion
in the system..

Maybe that's what I was seeing - it was a sort of shiny bright green. I'm pretty sure I've heard Brundle talking about glycol in the past too, but he could be wrong as well.

C

[Craigy]

The more I think about it the more downsides I can see...I guess you are the opposite!

Such a cool site this one =D>

Lol, I just like kicking novel ideas around

C