Re: Critical Wing

From:         GWilson404@aol.com
Date:         13 Sep 96 03:03:39 
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In article <airliners.1996.1775@ohare.Chicago.COM>, Al Klooster
<mooney1@primenet.com> writes:

>I was wondering if anybody can help me understand the concept behind a
>Crtitical Wing.  I have a small background in aerodynamics so please
>don't be afraid of getting technical. Thank you

The term more generally used is supercritical wing, which means that the flow
over parts of the wing exceeds the speed of sound. On old fashioned wings
this was avoided, since the supersonic flow would normally then form a shock,
which would cause a shock wave on the wing leading to high drag, boundary
layer separation, buffeting and loss of lift. In the seventies wings were
therefore designed to give just sonic flow over a good proportion of the
upper surface (say 40% chord).

 With the advent of modern computational aerodynamics it is possible to shape
the wing such that the flow decelerates with only a weak shock and therefore
none of the above penalties to any significant extent. This allows you to
design the wing to be thicker and therefore lighter and able to contain more
fuel.

Hope this helps,

Gerald Wilson