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Yes. Ed has been a great help. The formula accurately
predicted my current BTU rejection as compared to the Renesis dyno data
merged with the Eaton M64 SC data. Hope it holds true for the new duct. However
when you change things you never know. I had to enlarge the defuser duct also so
that may have change other things.
Bobby
Bobby,
Is that one of Ed's formulas?
George ( down under)
isn't the inlet
face area supposed to be 30% to 35 % of rad face
area
Based on the data I've collected 26% should give me
the correct heat rejection for climb out at 100 mph. Just have to see if it
actually works.
Bobby
My mistake Bobby, I'm working too
quickly and not concentrating enough. 775 to 800 cu" should be enough rad
volume - however isn't the inlet face area supposed to be 30% to 35
% of rad face area.
I suppose your looking for min drag?
George (down under)
George,
Have not changed the heat exchangers. Just the plumbing
and shortened the hose loop by about 18 inches. The increase from 21 to
26% is the opening size to core face ratio. I have about 272 sq in of
core face and the opens are now 72 sq in. If this test doesn't work I will
be adding a small oil to air exchanger in parallel with the oil \ water
exchanger with dedicated inlet and reducing my Rad inlets back to 21% /
58 sq in. Actual core size is about 775 not 800 cu in as I stated
earlier.
Glad I have the molds for all this stuff.
Bobby (still wondering about Tracy's
cooling solution)
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On Behalf Of George
Lendich
Sent: Thursday, October 01, 2009 2:53 PM
To:
Rotary motors in aircraft
Subject: [FlyRotary] Re:
Activity
Bobby,
I've seen between 3 to 3.5 cu" per HP, I
guess that depends of how well the cooling is set-up, 800 cu" of Radiator
should do fine for 250hp.
If your previous exchanger was 650 cu" for 250
hp it was undersized. I guessdamated that size form the info you previously
provided.
George (down under)
George,
I have 800 cu in of water to air exchangers. No oil to
air exchanger. At 6800 rpm \ 38" MP I'm producing close to 250 hp. But 15
hp is used to drive the SC. So about 3.2 cu in per HP. The new openings
are about 72 sq in. The goal is to lower the water temps from 200F to 185F
with an OAT of 100F. Oil is running 20F hotter than water. With the 21%
ratio I was only able to maintain 185 HP and keep the oil temps below 220F
\ OAT 95F. It all an experiment.
Bobby
Bobby,
What is your expected HP.
How does 26% of core face equate to 3 cu" for
every HP
i.e. 200 hp = 600 cu"
George (down under)
With any luck I will be back in the air
this weekend. I made several changes including opening my inlets from
21% to 26% of my core face. Of course it's no longer 105F so will have
to extrapolate the data. Other changes include relocating the battery
back to the stock location, removing 13lbs of tail ballets, new exhaust
manifold and belly mount muffler, CO Detector, exhaust heat for cabin,
O2 system, autopilot, 230 psi water spray for radiator and manifold
injection (yet to be tested), re-plumb the oil to water
exchanger and a fresh pilot bi-annual
today.
Bobby
Anyone out there ??.....................<:)
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