Byron Ward wrote:

There is a significant amount of blue toward the trailing edge of the wing
where there is reverse camber. Its not that obvious from the picture I
sent. I didn't design the tail, I just made the CFD model :) I think the
tail configuration is still not finalized. Actually I'm involved in
building a wind tunnel model right now so the configuration might change
as a result of that testing. The structure between the two fuselages is a
poorly modeled engine nacelle. 0-200 with a pusher propeller. We're still
working on the design/modeling of the nacelle. The configuration has been
updated quite a bit since this model. I just happened to have it around
and thought it might illustrate your point.

Byron

Thanks Byron.
Actually I like it. I think is solves a few problems with
pusher type airplanes. Lots of room for retractable
landing gear. I can see a few advantages with this layout.

Paul Lamar

Byron,

As a fellow simulations guy (25 yrs in FEA)  I would suggest that you
could probably reset the scale on your contour plotting software to make the
relatively small pressure differences over the fuselage more aparent.
I run into this same problem sometimes with stress contour plots.  Say
the default scale runs from 0 psi to 60,000 psi (blue to red thru the normal
colors of the spectrum of light -i.e. rainbow) with 0 blue and 60 ksi red.
If there is a portion of the plot where I might be interested in seeing only
a range from 5,000 psi to 6,000 psi, it will all look the same with a very
narrow range of colors.  To see the local distribution I reset the min contour
to 5,000 and the max contour to 6,000 - now I get the full range of
available colors plotted in the (narrow) range of interest.  Of course, the
higher areas are all the same color (max) and useless, but the limited range
is expanded out and the smaller differences (stress for me, pressure for
you) are now much more
apparent.

Hope this clarifies why Paul was having trouble seeing the deltaP on the
fuselage.  I'm sure the pressures changes over the sides of the fuselage
are much smaller than over the wing, and for most purposes, less important
and less interesting.   But, for siting air inlets and outlets, these
smaller differences *are* the real story.

Bill
Long EZ builder & pilot
mechanical engineer

 
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