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<DIV><SPAN class=822123515-18122006>Hi Jim,</SPAN></DIV>
<DIV><SPAN class=822123515-18122006>I have fiddled with this a fair bit, and the
setup I am using now produces very modest temperature rises on the
AXI.</SPAN></DIV>
<DIV><SPAN class=822123515-18122006>I see less than 15C rise after a P-07
with 84 A W.O.T. current draw at the beginning of the flight. After the flight,
static W.O.T is more like 75 or 76 A.</SPAN></DIV>
<DIV><SPAN class=822123515-18122006></SPAN> </DIV>
<DIV><SPAN class=822123515-18122006>The inlets total up to just about 1 square
inch, which is ducted straight to an airbox that surrounds the front of the
motor. The inlet airbox is about 5/8" deep from front to back, and has
plenty of volume, just because it needs to evvelop the front of the motor and
the cowl inlets. The airbox has a hole through wich the motor can passes, and
the hole is extended with a sleeve that runs back to near the aft end of the
rotating part of the motor.</SPAN></DIV>
<DIV><SPAN class=822123515-18122006>The wrapped balsa sleeve has maybe 1/8"
clearance around the motor. The high pressure air in the inlet airbox is forced
to either flow closely over the outside of the motor or through the holes in
the motor. </SPAN></DIV>
<DIV><SPAN class=822123515-18122006>For motors such as the Pletty, where the
prop drive does not stand proud of the front of the motor can, a drive extender
washer maybe 1/2" long will improve cooling by providing some volume inside the
inlet airbox, and allowing the air to "turn" to flow along the motor axis. This
is actually important.</SPAN></DIV>
<DIV><SPAN class=822123515-18122006></SPAN> </DIV>
<DIV><SPAN class=822123515-18122006>The warm air then dumps into the aft end of
the motor compartment, which is segregated from the rest of the cooling pathg to
the batteries.</SPAN></DIV>
<DIV><SPAN class=822123515-18122006>An separate outlet gets rid of this air. In
my case, it is simply a hole in the bottom of the "scale" cowl of the
Funtana. Ideally, the aft end of the cheeks that everybody seems to be
putting into their designs would be an ideal low pressure-high velocity outlet,
but everybody belnds them into the fuse instead of leaving a back end exit like
the Pylon guys.</SPAN></DIV>
<DIV><SPAN class=822123515-18122006>You could just have the motor sleeve dump
into the fuse above the batteries, but rear-facing exhaust stacks or a fake
turbo-prop exhaust would look cool and be functional. I'll try to post some
low-res pictures on the list.</SPAN></DIV>
<DIV><SPAN class=822123515-18122006></SPAN> </DIV>
<DIV><SPAN class=822123515-18122006>later,</SPAN></DIV>
<DIV><SPAN class=822123515-18122006>Dean</SPAN></DIV>
<DIV><SPAN class=822123515-18122006></SPAN> </DIV>
<DIV> </DIV>
<P><FONT face="Times New Roman">Dean Pappas</FONT> <BR><FONT
face="Times New Roman">Sr. Design Engineer</FONT> <BR><FONT
face="Times New Roman">Kodeos Communications</FONT> <BR><FONT
face="Times New Roman">111 Corporate Blvd.</FONT> <BR><FONT
face="Times New Roman">South Plainfield, N.J. 07080</FONT> <BR><FONT
face="Times New Roman">(908) 222-7817 phone</FONT> <BR><FONT
face="Times New Roman">(908) 222-2392 fax</FONT> <BR><FONT
face="Times New Roman">d.pappas@kodeos.com</FONT> </P>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT
face=Tahoma>-----Original Message-----<BR><B>From:</B>
nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org]<B>On Behalf Of
</B>J.Oddino<BR><B>Sent:</B> Friday, December 15, 2006 7:13 PM<BR><B>To:</B>
NSRCA Mailing List<BR><B>Subject:</B> [NSRCA-discussion] Cooling
outrunners<BR><BR></FONT></DIV>
<DIV>It would seem the best way to cool outrunners that have holes in the case
on the end that faces the nose ring, would be to bring air in through the
spinner and through holes in the backplate. Wondering if anyone has
really thought about the optimum design. I can picture internal vanes
but perhaps cutting off the nose of the spinner and leaving a big hole would
be adequate. Anyone tried anything like this?</DIV>
<DIV> </DIV>
<DIV>Jim O</DIV></BLOCKQUOTE></BODY></HTML>