Wow! Great Jarrett. Shows the rad is working as a turning vane.  The negative
pressure can be enhanced with an increase in rad angle. Thanks a  bunch. This is
encouraging indeed. This may actually improve the flow into the prop.
If you get time please try it with out the rad. I also think a one  inchthick rad of larger dimensions will work great.
Paul Lamar

More to digest...  the pic names call out there perameters..

I think we're getting some 'wall effect' w/ this model but...  it's  a start
anyway.

Btw, on the lower speed ones w/ no rad.. the bottom left corner is
developing
into a vortex.. it has ~1/3 of a turn in the model..  some place  between
that
60mph and the 120 is the sweet spot..  at 120 it's totally  turbulant back
against
the body after the max camber point..

HTH

Jarrett


Classic separation. Just as I thought. The Goose fuselage is way  too stubby.
No wonder they have all those problems with the pusher prop. The  pusher
prop is
operating in a nightmare aerodynamic environment.

The rads will kill two birds with one stone. Turning vanes and  cooling.

Yes I did notice the wall effect. It could be moved out a bit.
the last thing to try is a one inch thick rad instead of the current 2
inches thick.

Thanks for doing this Jarrett. Half a dozen Goose builder should  also thank
you.
Final adjustments in the real world can be made by moving the rad  in and out
and changing the angle. Scott Getting's full scale pickup truck  wind tunnel
will
tell the final tale.

Paul Lamar

It has occurred to me that one major modification that should help  greatly
is a
longer and bigger canopy. Extend it right out to the nose of the  aircraft.
That
will smooth the flow along the sides of the fuse. The boundary  layer may get
thicker but that is the lessor of the two evils.

-------------------------------------------------------

On further thought move the existing canopy 18 inches further forward
and make up the back part with fiberglass or carbon fiber for  stiffness.
Move
the hinges forward at the same time and notch the top of the fiber  glass
part to
accommodate the hinges and a longer cowl. This will lengthen the  engine
cowl and
give more room in the cowl for rads or ducts.

Then put flat side windows in the fiberglass back part to restore side
viability.

This would be cheaper and better than a whole new plexi canopy.


Paul Lamar
-- 


Note that all the completed pix show VGs all over the side of the  pylon.
The manual says do not fly without these devices.

The additional space for radiators would definitely help.   One  might could
move the canopy forward a few inches, but 18" would require a new  canopy
altogether.  The seating, CG, instruments (which come up with the  canopy
opening), and structure are some significant issues that would all
complicate moving the canopy forward.

I'm trying hard to get some good data on the pylon airflow.

Scott Gettings


Thanks Scott.
Please take some pictures of your pitot tube positions on the mock up.
Static pressure taps are nice but velocity rakes give a direct read  out
of air velocity. Air velocity through the rad is the bottom line.
Also short strips of cloth taped to the sides of the mock up
with a small digital camera taking movies of them would
also help. Turn the camera on jump in the truck and take off :)

The rads, located where advocated, might reduce the need for
some of the VGs. Turning vanes accomplish the same ends as
VGs. They attach the flow that becomes separated.

Paul Lamar

-- 

You can see the holes for the intended locations of the pressure
ports on the sides of the pylon.  (Yes that is Bondo, but you said it
should be smooth and it ain't flying!).    I'm also planning to have
pressure measurements on the front and back sides of any turning
vanes  and/or radiators.

I also included pix of a known GG vane installation that worked.   I
also built an X-plane model but had a hard time with some of the
pylon and tail interface areas.

Scott Gettings

We need velocity rakes in three places. One would do and move it  from
place to
place on three separate runs. I drew them on some 3D's.

Paul Lamar


Got it, thanks.

Scott Gettings