Hey George
Ed doesn’t have any formulas, he
just gets them from other sources {:>).
However, K&W indicate that anywhere
from 25% to 40% of core face area for an opening may be valid depending on your
core fin density, thickness, air velocity, etc, etc.
Ed
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of George Lendich
Sent: Friday, October 02, 2009
4:25 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: Activity
Is that one of Ed's formulas?
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.
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of George Lendich
Sent: Thursday, October 01, 2009
5:04 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: Activity
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,
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
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,
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
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
On Behalf Of George Lendich
Sent: Wednesday, September 30,
2009 7:31 PM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: Activity
What is your expected HP.
How does 26% of core face equate to 3 cu" for every HP
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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