Pressure or velocity for better cooling?

[Birel99]

Sorry for this being a bit off topic.

Is their an ideal radiator angle for the most cooling?

[Belatti]

I would say that the angle for most cooling has to do with the angle of the fins



Typically 90° to the direction of the airflow. The counterpart of this angle may be drag.

[Conceptual]

With the sidepod openings getting smaller every year in F1, I was expecting to see plain circular inlets that would accept the incoming air off of the tips of the cockpit wings (Ferrari's looked like it did this) in the form of a vortex.

I wasn't sure what the best radiator angle would be good for that kind of feeding, but I imagined a twisted design with aluminum "hairs" instead of louvers so the swirling air could then easily pass through, and exchange alot of heat in the process.

But oh, well. The new sidepod rules assures that they will never become circular, and the no furniture rule rules out the vortex generator, so we will see what cooling solutions 2009 brings.

[xpensive]

In early 1978, Gordon Murray tried out some sort of "Surface cooling" system for the Brabham BT46, which to my knowledge never raced. Does anyone have any info on the theory behind that?

[Flummo]

Don't know anything more than that I have seen it mentioned as "earlier cooling problems" in descriptions of the Brabham fancar (the one with a huge "cooling" fan, designed to create vacuum under the car for lots of extra downforce).

[tomislavp4]

There´s not much info on that one. All I know is that it didn´t work They did one test session with it, found out that it didn´t work (possibly blowing the engine) and continued testing with standard cooling architecture.

One of the problems with the design is that you have to make the air push onto the cooling "stuff" and to accomplish that the surface has to be inclined. On the Brabham the surfaces were not inclined as I recall

[xpensive]

This is what I found on the web, unfortunately only some blurry pic's without any technical explanations.

http://www.wrac.co.za/NewsLetter/May2006/Branham.pdf

[tomislavp4]

Something like this would work better I think...

But the benefits of the whole idea would be gone because you´ll have higher drag

[xpensive]

Never mind the shape, how was Murray's design intended to work, where is the cooling-water passing thru?
I just don't get it.

[tomislavp4]

Something like this I guess

Air flows above it, cooling the whole thing wich cools the water in the pipe... Just a guess

[xpensive]

Could be, with a larger number of smaller tubes perhaps, but still, some spaghetti?

http://www.wrac.co.za/NewsLetter/May2006/Branham.pdf

[DaveKillens]

Please read this. http://en.wikipedia.org/wiki/Radiator

In the F1 environment, ram air is directed into a duct, the duct flows to a radiator, and the warm(er) air expelled. If the air flows too quickly through the radiator, there is not much time to transfer heat, and the process becomes inefficient. So a diffuser is built in between the inlet and radiator to decelerate the air flow so that it spends more time in contact with the radiator elements, and more heat is transferred. Remember, aero drag is important, and the goal is to keep the inlets as small as possible (to keep drag low) while still being as efficient as possible in transferring the heat.

The surface radiator relies on air flow along a surface, where the heat transfer takes place. Air does not flow through it, just along it's sides. The advantage is that it provides incredibly low drag, but at the risk of many complications. Compared to current systems, it is more complex, less efficient, and weighs more. Here's an example of a surface (actually two, one each side of the fin) radiator on an old, but famous land speed record car.
http://www.brooklandsarchives.com/Galle ... get33.html

[xpensive]

In all honesty, I doubt if that Brooklands thing is very representative of the BT46 surface-cooling technology.

[DaveKillens]

It's exactly the same principles, albiet the materials and technology are generations apart.

Both the Brabahm and Bluebird used surface radiators to reduce aero drag to it's lowest possible factor.

[xpensive]

I'm still not convinced DK, I belive that the Bluebird is just sporting conventional radiators mounted at a zero angle to the car's direction, still relying on air passing thru itself due to a difference in air-speed/pressure between its sides.
You can see similar applications on conventional F1 cars of the 70s, March 761 if I'm not very much mistaken.

Gordon Murray's BT46 however, has clearly only one-sided cooling elements, why I cannot for my life understand how they actually work.