10 replies to this topic

[SalutGilles]

Right. Engines need to be cooled, so they run air through those giant radiators. trouble is, they're hell on the drag coefficient, making the car as aerodynamically efficient as a barn door.

What if the radiators were enclosed, and instead of air running through them, a mixture of compresed liquid nitrogen and ambient air was blown through the coils. the weight penalty would surely be overcome by the slippery shape, and there wouldn't ever be grass or gravel which begged to be dug out during an unnecessary pitstop.

Would that work, or am I crazy?

[Jonathan]

SG

I still think one of the most ingenius ideas ever came from Gordan Murray's 1978 Brabham BT-46 (No, not the "Fan Car") but the origional design for this car.

This featured a "double-shelled" aluminum honey-comb body stucture that would be used as the radiator. (Brillant Idea !!!)

Unfortunatly the idea was never made practical and conventional radiators were rather hastily adapted.

While I dont see this working with carbon-fibre nowadays, I think had he been successfull we would all be talking about those Brabhams, even today, and the Lotus-79 would have been forgotten. (...well maybe thats a slight exageration).

[Christiaan]

Jonathan, tell me more about this radiator system

SalutGilles:- well thats an interesting idea. One wonders how efficiant the radiators would be. I mean, as it is they are not too effiecint. Remember they used to spray the engine hood with dry ice in last year to get an extra 5Hp out from cooling. I think FIA also limits the dimensions of the radiator.

One point is that the drag coeffiecients of an F1 car are primarily due to the open wheel formula. One wonders how big an effect the radiator opening (which is usually partially covered by barge boards)has on the Cd value.

[Ursus]

Actually it would be illegal. You can´t rely on the vapourization of any fluid as a mean for cooling. Anyway, storing the liquid nitrogen would pose some problems if you didn´t want it to boil away halfway trough the race.

------------------
Ursus
Trust me, send money.

[Ruud de la Rosa]

I've heard that Barge board were there to guide air to the side-pod, but it looks to me that the air is kept away from them by the barge boards.

[Christiaan]

to slow down the air, since the radiotors can make use of only so much without incurring drag penalities

[Jonathan]

Christiaan

If you have not already done so, please take a look at the Nastalgia Forum. While I couldnt get much information on the origional radiator set up (It was never raced), enough of us old fogies knew enough about the car to discuss it intelligently..

Someone actually posted a picture of this car (with the origional radiator setup). Take a look, I think you will be impressed !

[Christiaan]

Impressed I was, that car looks very unique

[PDA]

Christiaan

The Muray designed Brabham used surface mounted radiators. The radiator heat exchangers (the "honeycomb") is mounted directly under the external skin of the bodywork. It seems that this is a fairly common practice in Aeroplanes. Unfortunately for Murray, there was insufficient surface area for teh system to work effectively, so he had to revert to side mounted heat exchangers in pods, as everyone else did.

The intent was to avoid the drag associated with standard cowled heat exchangers (probably worth the equivalent of 50 or 60 HP if it had worked)

[PDA]

SG - your ponderings may not be so wide of the mark. I was evcently reading in race Car Engineering that some teams (unnamed) are working on cooling systems which lose the side mounted radiatoir pods and the parasitic drag that they casue. Unfortunately, the article gave no indication of how this was to be achieved. However it is to be done, a hell of a lot of heat has to be absorbed/dissipated. Murray's suface mounted radiators was a brave attempt to gaiin an "unfair" advantage. I wouldn;t have thought that the same technique would be successful today, so the designers must be dreaming up really novel solutions.

[Yelnats]

Actually radiators account for a very small part of areodynamic drag on a modern F1 car, in the order of 5%. With all the wings and tires hanging out in the breeze, an F1 car is about the most inefficient thing on wheels.

In the early sixties, when cars were at their slipperiest, tires accounted for 80% of the drag. This was with the old front-mounted rads which were caused more drag than todays flank mounted rads which are shielded from the air blast by tires and deflectors. The biggest gains could be realised by increasing coolant temps by using liquid sodium which would make surface rads practical due to vast increases in radiative cooling and less reliance on the convective cooling used today.

But developments in this direction are sure to be deemed illegal by the FIA as all the other new technologies have been recently.