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Augmented Cooling


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#1 Charles E Taylor

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Posted 11 September 2008 - 09:40

Augmented Cooling .



I would like to know if any contemporary racing designs use Exhaust Augmentation in the radiator exit ducting?

It is well understood that this type of arrangement can produce considerable negative pressure in the expander duct. I wonder if any current designs make use of this facility?





Charlie.

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#2 cheapracer

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Posted 11 September 2008 - 12:07

C E T on a similar note some engine builders use "E A" to create low pressure in the engine/sump itself to help get the oil rope off the crank - equalising the low pressure area behind the crank webs where the oil clings too. Helps to control oil piston ring scavanging as well and some use lower tension rings because of it to get a hp or 2.

Simply a pipe to the exhaust from the engine with a 1 way reed valve.

As some may know some car co's (Mazda and the Mazda Fords for 1) used a similar system to get air into the exhaust port to help burn waste in the exhaust itself for aid in pollution control. If you take the ex manifold off you see the pipes in the manifold that stick well into the exhaust ports, thats them and the couple of large round thingys with pipes to the air filter are the reed valves.

#3 jatwarks

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Posted 11 September 2008 - 12:59

Use of exhaust gases for all sorts of things, as well as those mentioned, is quite common.

The most obvious is the recycling of the energy that would otherwise be lost through the exhaust; exhaust turbines compressing the inlet gases, now outlawed in F1.

Exhaust systems are also occasionally used to create low pressure areas beneath car components by blowing across their lower surfaces to generate additional downforce (lift).

I've often wondered if exhaust turbines could be used to advantage for things other than turbo-charging, once that was banned. The loss of so much untapped energy goes against the grain.

It's just a matter of justifying the additional complexity; cars can easily be built below the weight limit to accommodate turbines, although movable ballast would be reduced.

Pumping gases around was ideal as the masses and resistance were low. However, could an exhaust turbine combine with KERS technology to regenerate additional drive ?

How about driving an alternator and the ancillaries, rather than have those bleed power directly from the engine ?

The possibilities are endless.

There again, the rule makers in F1 wouldn’t like it.

Exhaust gas energy is readily available, after all.

All comments welcome.

Jim.

#4 Charles E Taylor

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Posted 11 September 2008 - 14:55

Augmented Cooling .



I would like to know if any contemporary racing designs use Exhaust Augmentation in the radiator exit ducting?

It is well understood that this type of arrangement can produce considerable negative pressure in the expander duct. I wonder if any current designs make use of this facility?


___________________________________________________________________________________________


My interest was in possibly reducing the size of the cooling requirement, but I would not disregard other uses of the exhaust plume.





Charlie.

#5 Greg Locock

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Posted 11 September 2008 - 23:46

Back at Lotus I worked on an alternator powered by a turbo. The electrical design is pretty straightforward. An alternative would be to use Peltier devices to use the exhaust heat - which the engine boys would not complain about as much.

#6 jatwarks

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Posted 12 September 2008 - 08:04

Originally posted by Charles E Taylor

My interest was in possibly reducing the size of the cooling requirement, but I would not disregard other uses of the exhaust plume.

Charlie. [/B]


Charles,

Fluid Dynamics are certainly a prime science, in F1 particularly, at the moment. Airflow through and over the car is studied in minute detail now.

One thought that comes to mind, with regard to your original question, is the relative velocity of exhaust gases, when compared with external airflow.

The myriad 'control' surfaces that exist on the cars now, from barge boards to winglets, are used to direct and accelerate airflow into and around the car as efficiently as possible. Could it be that channelling and accelerating the airflow, by creating vortices over the bargeboards and into the radiators, is more effective than using exhaust generated flow ?

I believe that exhaust generated (negative) pressure would be less consistent than that generated by the car's motion: I'm sure this was the problem with exhaust generated downforce (lift); the additional grip varied with engine speed, rather than car speed.

Jim.

#7 LMP900

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Posted 12 September 2008 - 18:41

I used it on an LMP car, both to improve the cooling air flow and to increase the wake pressure behind the rear tyres.

http://i493.photobuc...oto/coanda1.jpg

It certainly worked in the workshop! I couldn't quantify the improvement to the cooling though I'm afraid.