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<DIV>In a message dated 2/20/2006 2:04:45 PM Eastern Standard Time,
simestd@netexpress.com writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000 size=2>If
you've ever taken a close look at the<BR>engine installation on a high
performance piston aircraft, the cowling<BR>is typically very tight by pattern
standards and they have nowhere near<BR>our 3:1 outlet:intake rule of thumb
for cooling. Instead they make<BR>extensive use of baffling and ducting
to control the air path and make<BR>it work for them.</FONT></BLOCKQUOTE></DIV>
<DIV></DIV>
<DIV>It's "elementary" Thermo 101 kind of stuff with a little fluid dynamics
thrown in for good measure. Keep the air in the turbulent regime around the
engine to maximize cooling effectivess. To some degree, we did that in our
earlier designs by maintaining a slender fuse and cowling in tighter by
necessisity.</DIV>
<DIV> </DIV>
<DIV>With the advent of the Pachyderm fuses, we copied full scale size-wise but
with little forethought about cooling. Having a large bucket of dead air up
front in our fatso fuses does nothing for the engine/motor. Slows the plane down
tho.</DIV>
<DIV> </DIV>
<DIV>And BTW, the exit really doesn't need to have 3X the entry area to be
effective if properly designed to draw the air out. Remember Bernoulli?? </DIV>
<DIV> </DIV>
<DIV>On the other hand, with so many of us having stopped building, where's the
creativity and innovation going to come from? It saddens me to see a whole new
generation of "modelers" who only want to fly, using ready made everything. It
does produce wonderful piloting skill tho.</DIV>
<DIV> </DIV>
<DIV>Matt</DIV></FONT></BODY></HTML>