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Posted for "sqpilot@earthlink" <sqpilot@earthlink.net>:
Hi, Ed.....While looking at the various evaparator cores in the
catalog at
AutoZone, I came upon two cores that are 7 inches thick. The one I am
interested in is 8 3/4 x 8 3/4 x 7 inches thick. If I were to use two of
these side-by side, I would have a cooling area of around 1071 sq.
inches.(minus end tanks, etc) Getting the air to flow through a 7"
thick
core might just work in my canard at 200 mph, but of course I'm
concerned
about take-off and climb. I can live with higher speed/lower vertical
climb
operations, I am most interested in perfecting cruise operations, (which
should constitute about 95% of my flying) For ground operations I might
be
able to find a small enough diameter fan. If I could make this work, it
would be a neat, compact installation that would fit rather nicely in my
SQ2000 without having to modify the cowling, etc. What are your
thoughts on
an evaparator core that is 7" thick? Thanks in advance for your
thoughts
and opinions. Paul Conner
>> Homepage: http://www.flyrotary.com/
You may be able to make this work, but it depends on the core design.
And with that amount of frontal area the max inlet diffuser ratio you
can get is maybe 4 (scoop size to rad size); so that limits the pressure
recovery available. If you are going to venture that far from "proven"
(I use the term loosely) design, I'd suggest you do a flow test to
determine pressure drop before trying to go fly.
Sure, doing a bench test takes some effort, but probably a lot less than
trying to solve an unworkable cooling system as part of your test flight
program. If you need to, get an engineer friend to help. A flow test
isn't that tough. I decided to test my radiators and oil cooler, even
though I'm working within a range that seemed pretty safe. I got the
largest centrifugal blower that I could find from an Heating/AC vendor
(took it out of a scrap furnace they had in the yard, paid $5.00 for it
and a length of 8" duct). Rigged it up with my intake scoops, and
measured drop across the cores using a simple water manometer. Measured
flow with a small hand-held aerometer. The blower only gave a flow
rate of a little over half my design point, but with some regression
analysis in a XL spreadsheet I could get a formula to extrapolate out
with good accuracy.
It's only a piece of the total picture, but it gives me confidence that
things are going to work when I go fly.
Al
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