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<DIV><SPAN class=210254714-05122006><FONT face=Arial size=2>Hi
All,</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial size=2>I'll go one step
further: measuring the exit area by looking at the bottom of the airplane is
wrong. Do you want the air shooting vertically out the bottom of the ship? Of
course not.</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial size=2>The expansion of air
in our cooling setups is practically negligible. Let's say that the air heats up
a whole 100 degrees F as it goes through the system. There is no way that
it heats up even half of that. On a normal day, the air is at at roughly
535 degrees absolute, so a 100 degree warmup will make the air expand less than
10%.</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial size=2>If you take a square
inch of air into the front of the airplane at 80 MPH, you want 1.1 square inches
of exit ... as viewed from directly behind the aircraft!</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial size=2>Now if you cut a
hole in the bottom of the plane, you have to ask how the air is coming out. Is
the hole really aft of the fuselage bottom "high point"?</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial size=2>Is it really on the
flat bottom? Then air is going to exit the plane at some shallow angle, and the
effective area is going to be much smaller than what you see looking at the
bottom of the plane.</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial size=2>Unless the exit hole
is huge, this means that the system is outlet choked, when flying at speed, and
adding drag to boot.</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial size=2>We really should
build aft-facing exit scoops like some older Pattern designs, or the slick
trick used on the aft end of the belly pan of the Zeque.</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial
size=2>Later,</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial
size=2>Dean</FONT></SPAN></DIV>
<DIV><SPAN class=210254714-05122006><FONT face=Arial
size=2></FONT></SPAN> </DIV>
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