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Unread 03-08-2005, 03:18 PM   #5
bobkoure
Cooling Savant
 
Join Date: Feb 2003
Location: USA - Boston area
Posts: 798
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Quote:
Originally Posted by Jimbo Mahoney
half a chord-span?
Oh, sorry - mu co-workers are a bunch of airplane and soaring geeks and I forgot it's specialized knowledge.
The blade of an axial fan is a wing. A chord is an imaginary line connecting the leading edge with the trailing edge. Coanda effect is, essentially, progressive laminar flow across the top surface of the wing that turns it into a scoop, pushing air down behind the trailing edge. The effect extends upwards from the wing, but usually no more than a half chord (depends on the wing, airspeed, some other stuff which I mostly don't understand), but it's a top surface effect. Ever notice how most axial fans are exhaust-over-struts, or, for that matter, how fighter planes bolt all sorts of stuff to the underside of the wing?
Anyway, for the axial fans we mostly use, it isn't much distance at all,...
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