Cooling Modifications Experiment for the Track: more air flow through radiators to keep battery temperature down

[Dee]

Based on Franks comments, I’m sceptical how effective aero bits developed in the 70’s are. You don’t see fan wheels around in modern cars.

Well, I don't want to get into a discussion with a F1 engineer but there's plenty of theory and real life tests about the advantage of aero wheels on EVs.
For example:

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[f1eng]

Well, I don't want to get into a discussion with a F1 engineer but there's plenty of theory and real life tests about the advantage of aero wheels on EVs.
For example:

Definitely can reduce drag.
That was not under discussion.
Probably, almost certainly, can't pump enough air through the hub to improve cooling, which was..

 

[Dee]

Probably, almost certainly, can't pump enough air through the hub to improve cooling, which was..

I think it can.
Every wheel that rotates is an airpump, some very efficient, some not so efficient, depending on shape.
There's no debate in there.

Like you said, the debate is, is it enough to help the cooling?
It may be.
For road cars it's more important to have less drag than improved cooling of the brakes cuz you don't really need that on road cars.
On race cars you need both, maybe brakes are even more important.
Maybe that's why the focus of road cars is on drag and not cooling.
That doesn't mean it doesn't work on road cars when you put the focus on cooling.
That's why this thread is interesting to see if that is the case but you need specific wheels to test that, in various set-ups.
That would be absolutely great.

This is a Lancia Delta on a tarmac stage in the good old days.
Gravel stages aren't that demanding on brakes (less grip) so that's why you only see it in this set-up.
Modern rally cars have bigger wheels and I suppose they don't need the aero disks anymore cuz of improved brake design and bigger, open wheels.
Or the benefit wasn't that big and/or others just didn't bother.
I don't know if wheel design is in the regulations nowadays though...

 

[Dee]

Let's suppose wheels can help to dispensate heat from the brakes and therefore create a flow which can help improving the cooling of the radiator in the wheel well too.
By adding "fan wheels" you may improve cooling of the radiator but on the other hand you may disturb the air flow around the car which may lead to more drag which will lead to more power consumption which will lead to more heat.
Do you see the vicious circle here?
So there may be a good reason "fan wheels" aren't used on road cars, who knows...

With ice cars cooling was never an issue but with EV cooling is much more important, in a much smaller bandwidth.
So maybe it's time to look at cooling of EVs in a different way.
Cooling was always on the front but EVs need a more efficient body to help improve efficiency.
So why not take the cause of the problem away instead of solving the effects?
It would make sense to put radiators in the back:

1. It may reduce drag at the back (improves efficiency).
2. Flow from the sides goes into the rear wheel well and also may contribute to reduce drag at the back.
(No high pressure in front wheel well any more, new wheel designs incoming as well).
3. It may be even an idea to create a blown diffuser, like Brawn Racing did in F1 which will improve handling at high speeds.
Gordon Murray also uses a fan in his T50 to force the diffuser to work more efficiently although it spins at high rpms to achieve that...but hé, airflow is airflow.
4. You don't need cooling openings at the front anymore (except brake ducts) so it may improve overall Cw value and therefore efficiency.

With the coming of EVs there are new possibilities.

 

[Dee]

Damn, I need a windtunnel.
Again....

 

[Bognar67]

Or something like this...

It was mainly for cooling the brakes (Porsche 935).
I think Rotiform has these wheels with aero disks if I'm not mistaken.

Manthey uses similar on the latest 911 GT developments but only on the rears.

 

[Dee]

Manthey uses similar on the latest 911 GT developments but only on the rears.

Love those wheels btw.
Maybe for aero or heat (cuz of rear motor set-up)?

 

[Bognar67]

Isn't that just for looks?
Love those wheels btw.
Maybe for aero or heat (cuz of rear motor set-up)?

Nothing for the looks on their cars 100%. Manthey Racing (911) cars are the fastest on Nürburgring Northshleife. Everything on their cars with purpose.

 

[bsclywilly]

Well, I don't want to get into a discussion with a F1 engineer but there's plenty of theory and real life tests about the advantage of aero wheels on EVs.
For example:

Aero wheels for drag reduction, yes. The cfd study I referenced in my previous post looked at several configurations. I was only referring to the efficacy of the 935 style wheel in pumping air out for brake cooling.

 

[rs38]

https://www.audi-mediacenter.com/en/photos/album/audi-q8-sportback-e-tron-quattro-2133

they stole your idea

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