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

Byron Ward wrote:

Thanks for the tip Bill. All of the work I have been doing has been
with the wing/fuselage junction, because we are very concerned about the
interference effects, since we are trying to set a range record. I've been
mostly looking at the wing and ignoring the fuselage, so as you said the
scale I was using worked fine.  Maybe resetting the scale will turn up
something around the fillets that I've been missing. Also we will
hopefully be modeling intakes for cooling/induction on the nacelle, so
that kind of detailed look at the pressure would be good there, too.
Thanks again.

Byron
wardb@engin.umich.edu

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