Venturi effect for Engine Cooling

[Don Woodward]

Hi All

Has any one used the Venturi effect for engine cooling of their Canard aircraft ?

I attach a image of what I am thinking. The exhurst gose into a large alloy pipe that is sealed at the back so no air can exit the cowl. The only air that can exit the cowls is through the large alloy pipe. Hence the Venturi effect with the exhurst in the allow pipe.


The Brantly Helicopter B2 uses the Venturi effect for cooling the engine.

Cheers Don

[Buly]

Yes, but we call it exhaust augmentation. I had it on my rotary installation.

[Don Woodward]

Originally Posted by Buly

Yes, but we call it exhaust augmentation. I had it on my rotary installation.

Who is "we"

Exhaust augmentation is a bit of a loos term. Exhaust augmentation dose not always use the Venturi effect.

Im being a bit

Cheers Don

[Lynn Erickson]

Originally Posted by Don Woodward

Who is "we"

Exhaust augmentation is a bit of a loos term. Exhaust augmentation dose not always use the Venturi effect.

Im being a bit

Cheers Don

Exhaust Agmented Cooling is where exhaust gases are discharged from a smaller pipe which is surronded by a larger tube. the venturi effect of the high speed exhaust gas traveling through larger tube causes a lower pressure and cooling air from the engine is draw through the tube increasing the volume of cooling air that passes through the engine cooling fins. and we have been using it for many years on several other canard aircraft, many other aircraft . most piston engine twins have it because they have the extra space required in their engine nacelles. on my aircraft both engine cooling and oil cooling showed a 10 degree drop in temps at cruse. gained about .5" to .6 " WC pressure drop with it.

[steelese]

I believe a few people have already done something like this. Look around in the forum and see what you can find. There are at least two post on this that I can recall.

[J Berki]

I am attempting to use exhaust augmentation to cool the rotary. There are some NACA papers that describe the testing. Charlie Airesman is probably the expert as he has successfully implemented this on a Vari EZ with a Subaru with direct drive. His earlier experiments were with a Honda engine. Room is at a premium for any system as the minimun augmenter length is around 20". Here are some shots of the augmenter ejector and mocked up difuser on the backside of the rad and oil cooler. A 5' long inlet scoop provides high pressure by slowing the air down. The diffuser will be part glass part metal as the headers come in proximity of the duct. CONTACT magazine puts out an annual book that has some attempts at augmentation cooling.
Joe Berki
Limo EZ
13b P Port

[Buly]

Here is my installation with augmentor:

[Marc Oppelt]

Joe - be sure to carry an extra rag with you to the fly-ins. You'll need something to wipe all the drool off your plane.

[E Racer Extreme]

I believe there is a photo of my augmenters in the 2005 RR photos. I had them for 4 years, very effective up to 200 kts, Mine were most likey too small above that airspeed. ERacer113

Jack

[Don Woodward]

Hi All

Venturi effect.

Thank you all for posting the photos.



Cheers Don