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.


Paul Lamar

There are trade offs to extending the canopy..

 - The entry might be made finer, but that doesn't necessarily
contribute to less turbulent flow.  Rain drop shape - subsonic forms.

 - More glass is more wetted area.

 - More glass is more weight - Acrylic is heavy.

 - Having the windshield further from the eye can make the optics seem
worse.  There would be no chance to wipe fog/frost off of it if it's
out of arm's reach.  Defrosters aren't always effective.

On the Glass Goose, my impression is that the distance from the widest
part of the cabin to the prop is too short (for best flow).  The cabin
can't taper properly to avoid flow separation.  Making the cabin
extend further forward doesn't fix that problem.  Moving the widest
spot forward would, but there would obviously be other problems with
doing this.


Regards,

Matt-

To Everyone,
I have a rather long post that addresses the cooling problem in this plane.
However, I'm not through
so I cant send it yet. Soon. I can respond to the flow separation on the
pylon wall. I have addressed
that issue by opening the augmentation slot wider, and allowing all cooling
and exhaust out through
this area. At the same time I faired the aft cowling smoothley into the
spinner and eliminated all the
air outlet at the back of the cowling. With the pylon walls spread farther
apart at the rear, it decreases
the angle at with the pylon walls converge. Less convergence, means the air
has a better chance of
staying attached. And since all cooling air and exhaust exits this area, it
will "fill-in" the area aft of the
augmentation slot and hopefully provide a good "bite" for the prop.
Frank R. Clementi