1450 Btu/min seems
high to me. That is 35HP. Where
do these numbers come from, do others agree with this
number?
Alex
Madsen
-----Original
Message-----
From: Rotary
motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen
Sent: Tuesday, December 21, 2004 10:32
PM
To: Rotary motors in
aircraft
Subject: [FlyRotary]
Re: Oil Coolers
Subject:
[FlyRotary] Oil Coolers
I have
found some really nice oil coolers for aircraft (and other) at
http://lytron.com/standard/he_aluminum.asp They are a little expensive but are
suppose to have great performance.
Does
anyone know how much what the average oil flow rate of the 13b is (Gal/hour)
and the required heat dissipation (W) or (BTU/hour)
Alex
Madsen
Alex;
Heat
dissipation to the oil is between 10 and 11 Btu/min per hp. My opinion
is to design for about 75-80% power, so for a NA 13B figure about 1450
Btu/min.
I’ve
seen different oil flow rate curves that don’t quite agree; but best figure
about 12 gpm at 5000 rpm, and fairly linear with RPM up to that point, maybe
hits 15-16 gpm at 6500. I’ve seen one dyno curve that maxed out at about
11 gpm; who knows –different pump, different back
pressure.
One
issue for us with rotarys is the flow rate 30% or so higher than the typical
piston engine; so its worth checking the flow – pressure drop data for “stock”
coolers designed for piston engine use.
Al