Re: Trailing edge wedge?

Date:         19 Apr 99 02:22:40 
From:         David Lednicer <>
Organization: Analytical Methods, Inc.
References:   1
View raw article
  or MIME structure wrote:
> Does anyone know what this wedge is, and the basic idea behind
> it?  Why is it only being introduced now?

    The trailing edge wedge is just as the name implies; a wedge added
to the lower surface trailing edge.  This was developed at Douglas by
Rob Gregg and Preston Henne in the 1980s and was originally called a
"divergent trailing edge".  Their idea was to create a faired-in Gurney
flap.  A Gurney flap is a very small (1-3% of airfoil chord) tab,
mounted normal to the surface on the lower surface trailing edge.  The
Gurney flap was developed in the 1970s by Bob Liebeck of Douglas, in
conjunction with auto racer Dan Gurney.

    As you can see, this was all originally developed (and patented) by
Douglas engineers.  I know that Boeing tested a divergent trailing edge
on a 737 in the early 1990s, but reported that all it did was increase
the lift produced at a given angle of attack.  Hence, Boeing has not
been very interested in the technology until as of late, when they
acquired McDonnell Douglas.

David Lednicer             | "Applied Computational Fluid Dynamics"
Analytical Methods, Inc.   |   email:
2133 152nd Ave NE          |   tel:     (206) 643-9090
Redmond, WA  98052  USA    |   fax:     (206) 746-1299