As far as BTU/min is concerned one BTU/sec is 1055 watts.
One BTU/min is therefore 63,300 watts I think.
One HP is 746 watts and a three rotor at full power of
300 HP will be putting about 100 HP or 74,600 watts
of waste heat into the oil cooler. Maybe a bit less.
Kind of fantastic claims for these coolers
as at 5 inches of water the way I see it at a 125 degree F
temp difference the chart claims 175 BTU/min or
11,075,500 watts!! or 14,849 HP! Sounds way too high.
Could be a decimal point off here and there.
Must be my arithmetic. Maybe my conversion factor is wrong.
Something is not adding up.
Can anybody help me out here?
Paul,
1 Btu/min = 17.56 watts
(You put the 60 in the wrong place, so are off by a factor of 3600)
So, 74,600 watts = 4246.206 Btu/min
175 Btu/min = 3074.509watts = 4 HP
Bill Schertz
KIS Cruiser #4045
I knew I screwed up somewhere. Thanks Bill.
That's at the other extreme. No way is this cooler going to work.
It will take something 20 times more effective.
Something still wrong I suspect. Perhaps this chart is wrong.
I checked the SW .pdf file and a 7" X 8" X 3.5" cooler
model number 10886A is 1025 BTU/min at 100 pounds of air per
min and 100 pounds of oil per minute. That is about 16 gallons of oil
per minute and 1300 cubic feet of air per minute.
It would take 12 inches of water to get this amount of air through
the cooler so no way would this work at 100 MPH. It takes
160 MPH to get near 12 inches of water.
A hole 5" by 5" at 100 MPH would be about 1500 cubic feet of
air per minute. That is about the largest cooler they make which still seems
too small.
It will only handle about 25 HP waste heat at 160 MPH.
Also there would be a 15 psi oil pressure drop through the cooler.
Everybody should download the pdf and study those SW curves. Very
educational even if the coolers won't work well enough.
Paul Lamar
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
