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Old 08-04-2013, 03:00 PM   #1 (permalink)
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Effect of front radiator on teardrop-shaped underbody?

If a car also had the underbody teardrop shaped, What would be the effect of air passing thru the front mounted radiator and then to the teardrop floor shape?

The radiator might slow down the air but also cause it to expand when heated.

In the sketch the radiator is shown in red.

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Old 08-04-2013, 04:30 PM   #2 (permalink)
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Not good. Ground vehicles interact with ground plane. Cut drop in half. Read Aerohead's posts instead of doing it all over again.
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Old 08-05-2013, 08:46 AM   #3 (permalink)
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The sketch is not showing up, and cut&paste don't work on the URL either.

I would think that the exit point of the radiator would have to be worked to a low pressure area, somewhat past the high point (but on the sides) for best effect.

Something gradual as to not disrupt the flow.
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Old 08-05-2013, 06:35 PM   #4 (permalink)
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front hole-to-floor

Quote:
Originally Posted by Big time View Post
If a car also had the underbody teardrop shaped, What would be the effect of air passing thru the front mounted radiator and then to the teardrop floor shape?

The radiator might slow down the air but also cause it to expand when heated.

In the sketch the radiator is shown in red.
I'd recommend you look at Dr.Alberto Morelli's work at Pininfarina's wind tunnel for the CNR
'banana' car of 1976-78.He used the tunnel to create extractors which delivered the engine bay air into the body at the same velocity so as not to trip up the flow.
Also,on the internet,there is an article about the E-Z HOOK LSR streamliner aerodynamic testing at Cal Tech's Guggenheim Memorial scale-model wind tunnel.
The E-Z HOOK has a nose inlet and has the lowest drag of any wheeled vehicle ever tested at Cal Tech (around Cd 0.105).
You might be able to glean something from the article.
There are no handy,user-friendly,one-size-fits-all solutions for this sort of thing.
Hucho does mention that a comprehensibly designed cooling system can add as little as about 2% to the overall drag of a passenger car.He shows some designs and there should be Walter Korffs low drag cooling system design in the Phil Knox's Aerodynamic Photos Albums.
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Old 08-06-2013, 02:49 AM   #5 (permalink)
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What are you not telling us? This is like http://ecomodder.com/forum/showthrea...ack-26505.html where the question was posed in it's simplest form, then it turns out he was asking about a motorcycle. What are you designing?

Lacking that about all one can say is the radiator needs a streamlined inlet duct before it *and* a streamlined exhaust duct after. The openings can be about 1/6th of the radiators cross-section. Inlet higher, at the (high static pressure) stagnation point, and exhaust farther back at 115 from the stagnation point. Use Coanda nozzles to cause the hot, pumped air to re-attach overall flow to the afterbody.

What else would you like to know.
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Old 08-06-2013, 09:20 AM   #6 (permalink)
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Quote:
Originally Posted by freebeard View Post
The openings can be about 1/6th of the radiators cross-section.
That inlet radiator drawing is posted as a page in a book one of the forum members scanned and posted in his gallery.

Attached below.

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