Zero drag radiators

[Tom]

Hammond has recovered fine (despite a rumoured new addiction to celary), he's driving again and will probably be back on the show sometime. It probably wasn't such a big deal as people made out, sure it was fast and he had brain swelling, but nothing worse than McNish in 2002 really.

[zac510]

I first remember reading about this concept several years ago in a mid-late 90s issue of Race Tech magazine. If I recall, although the article discussed it as plausible, the 'experts' dismissed it as the air speed or air temperature was simple not high/energetic enough or something to that effect.

Perhaps a consideration of the viability of this concept is that the teams almost universally use chimney extraction now, which would produce 'thrust' in downforce, not in the forward plane.

[RH1300S]

I first read about this in Carroll Smith's "Tune to Win" (boy was he ahead of the game!) - I think published in the late 1970's

He was making the point that the whole radiator duct and in particular the exit was very important (in those days some people didn't seem to think so) - he related it to piston engined aircraft (slightly more relevant air speed than jets) and said that (IIRC) the Mosquito achieved net thrust from it's radiators. Therefore at the very least race car designers should look hard at the duct design to minimise the overall drag through the cooling system.

Rather than worrying too much about net thrust, I wonder if it would be more relevant as to where the heated air re-emerged into the airstream; surely it could be used to modify the flow in tricky areas.

[DaveKillens]

As kilcoo mentioned, a radiator will posess drag. But a properly tuned intake and exhaust can produce thrust, and cancel out the drag from the radiator to produce an overall net drag almost zero.
The problem is, this design is optimzed for a certain velocity and altitude. In a production car where it has to endure various combinations of speeds and such, that doesn't work very well any more. A car can drive down an expressway at 100 kph, then sit idling in traffic for an hour... and there's no optimal radiator design that works for such extremes.

[ss_collins]

Has this concept been applied to a race car ever?

[zac510]

Has this concept been applied to a race car ever?

I like the idea of the FIA trying to ban this.

[G-Rock]

As kilcoo mentioned, a radiator will posess drag. But a properly tuned intake and exhaust can produce thrust, and cancel out the drag from the radiator to produce an overall net drag almost zero.
The problem is, this design is optimzed for a certain velocity and altitude. In a production car where it has to endure various combinations of speeds and such, that doesn't work very well any more. A car can drive down an expressway at 100 kph, then sit idling in traffic for an hour... and there's no optimal radiator design that works for such extremes.

While operating extremes of a road car may not make such a concept worthwhile, I'm sure that manufacturers of supercars (Ferrari, Porsche, Lotus etc) may showcase this technology. If you look at the ducting of a 599, or an Enzo; with all that time in the wind tunnel, there could be some usage of this technology couldn't there?

The question still remains however. Is this concept of directing air in and out of a radiator to minimize it's drag actually being used in practice in the racing/automotive industry? There have got to be some aerodynamicists on this forum...

[RH1300S]

The question still remains however. Is this concept of directing air in and out of a radiator to minimize it's drag actually being used in practice in the racing/automotive industry?

Don't worry about that - there is no doubt at all that in just about every sector of motorsport people are paying attention to this. Just look at the effort that goes into detailing around the radiator intakes and various outlets of an f1 car - barge boards, internal ducting, shark gill louvres, chimneys, heavily sculpted tight fitting rear bodywork etc. etc.

Even look at the radiator outlets on a GT40 - they are that shape not by accident, they are dumping air back right where there would be a low pressure area as the air rushes over the nose. Partly cancelling out the low pressure (& lift), but also this will help air through the radiators very well indeed at speed.

[persovik]

Has this concept been applied to a race car ever?

I like the idea of the FIA trying to ban this.

I guess it has been banned untill now. With FIA now encouraging energy recovery from heat, using the heat directly to provide some sort of propulsion should be just the ticket.

[Sah]

Years later this experiment was done here I leave the video

[hollus]

Full disclosure:
The video above is not about radiators. It is a zero drag mod on the whole car on the Codemasters game.
It is off topic but interesting nonetheless.

[Xwang]

Maybe you are all speaking about this:
https://en.wikipedia.org/wiki/Meredith_effect

[hollus]

They were... in 2007.

[e36jon]

According to his biography 'The Perfect Car', John Barnard designed this into one of his Ferrari cars while he was there. He alleges that he was sabotaged by the engine department giving him false information to design around hence dooming the car to struggles throughout the season.

[Rodak]

Here's a very good article about the Meredith Effect written by a pilot who built and tested a duct. He instrumented his project and got some real data; he managed to get to 104% recovery. Well worth the read with good information for anyone attempting to build a duct.

https://www.kitplanes.com/the-meredith- ... r-fiction/