[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

H2o cooled engine

Dear Mark,
I excerted your letter and hope I have answered your questions. Perhaps
some of the guys on the reflector are interested in this too.

you are using the standard SVX computer with modification? 

Yes but not much mod. Just speed sensor and pollution controls. I have a
scheme for the future to replace the O2 sensors with an oscillator
driven by the EGT thermocouples. David parrish is looking into an
intriguing simple back up system. I hope he will keep us posted.

I have been intrigued by the exhaust augmentation (jet pump) idea since
I saw
it associated with the rotary engine... was that in Contact!?  

Contact Issue 39 P 11 & 12 and CSA newsletter  #46 (april 97).

mentioned using 2 augmentor tubes which I suppose would be in
conjunction with 2 radiators?  How are you routing , isolating heat and
how much added
weight do you think you'll see with the extra plumbing. Will the
electric fans be

 Only one belly mounted radiator but the dual exhaust must be isolated
from each other or the pulses from one tend to neutralize the other (at
least they did on Bayard duPont's Defiant).I divided the radiator
airflow between the two exhaust nozzles. My exhaust  ,for now the  stock
3 into 1, but reversed stock exhaust manifords feed stainless U bends.
They curve forward (3 inch radius) and out the bottom of the fuselage
while turning aft into the throat of the duct. They are very short so
light weight.The duct work will merge back  up into the cowl and exit
through the cheeks on both sides through the prop. My temp indicating
labels never showed more than 130 degrees on the prop. The pumping
action of the duct within 2 inches of the prop helps significantly.
For first year I probably wont implement this plan on the plane. There
is too much other stuff to test and prove. My prototype with  home
heating duct had lots of 6 inch cracks after 20 minutes of testing. The
ducts should probably be made of carbon fiber  and much better shock
Heat isolation dosent seem  to be much of an issue with so much air
moving through the duct. The  metal duct never got too hot to touch.
Im crossing my fingers that radiator capacity will allow for some taxi
time without a fan. I like David Parrish's idea for a mist cooler
spraying the radiator during climb.  Hmm maybe combined with a pilot
relief tube...

I had problems printing the downloaded pics from awpi.com

Actually those are some pages from a book called Fan Engineering by
Buffalo Forge.
My wife a librarian is trying to get the book for me on an interlibrary
loan. Then I could get a better copy.
I have some pictures ,still in my camera, of my test rig. I will get my
neighbor to scan them and send them out if anyone is interested.