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<DIV><SPAN class=383364414-19122006><FONT face=Arial color=#0000ff size=2>Merry
Christmas Bob,</FONT></SPAN></DIV>
<DIV><SPAN class=383364414-19122006><FONT face=Arial color=#0000ff size=2>Oh
yeah! Any spinning duct without internnal stators has at least
one strike against it to begin with.</FONT></SPAN></DIV>
<DIV><SPAN class=383364414-19122006><FONT face=Arial color=#0000ff size=2>There
is some hope for one big hole in the middle of the spinner,
though.</FONT></SPAN></DIV>
<DIV><SPAN class=383364414-19122006><FONT face=Arial color=#0000ff
size=2>later,</FONT></SPAN></DIV>
<DIV><SPAN class=383364414-19122006><FONT face=Arial color=#0000ff
size=2>Dean</FONT></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>
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org]<B>On Behalf Of </B>Bob
Richards<BR><B>Sent:</B> Monday, December 18, 2006 8:08 PM<BR><B>To:</B> NSRCA
Mailing List<BR><B>Subject:</B> Re: [NSRCA-discussion] Cooling
outrunners<BR><BR></FONT></DIV>
<DIV>Dean,</DIV>
<DIV> </DIV>
<DIV>I was thinking that proper ducting would be a lot easier than trying to
engineer a way to force the air through the spinner.</DIV>
<DIV> </DIV>
<DIV>KISS.</DIV>
<DIV> </DIV>
<DIV>Bob R.</DIV>
<DIV> </DIV>
<DIV><BR><B><I>Dean Pappas <d.pappas@kodeos.com></I></B> wrote:</DIV>
<BLOCKQUOTE class=replbq
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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>
<DIV><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> </DIV>
<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>_______________________________________________<BR>NSRCA-discussion
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