Russell Kent wrote:

Monty,
I believe you need to move the mouth of your scoop farther forward, as

the picture indicates that it is currently at the leading edge of a low
pressure zone.

Additionally, why do you angle the trailing edges of the strakes back

towards the prop?  To my eye, this seems bad in that it (further) disturbs
the air fed to the propellor, without any other apparent positive effects.
Assuming you have no control surfaces on the trailing edge of the strake,
perhaps you could use a curved trailing edge to address the intersection
drag issue while still keeping the strake trailing edge far ahead of the
propellor disk.

Russell Kent

Monty Roberts wrote:

Russell,

Please describe the low pressure area which you are referring to.  The
location of the scoop is about the same as the original Rutan design. The
inlet area is a little different. The reason that I angled the strakes
rearward is that it is the same as the original aircraft. I was trying not
to introduce any unforeseen moments in the pitch axis. I wanted to maintain
the flying qualities of the original design. The strakes do tend to disturb
the airflow into the prop. On the Long EZ Burt seemed to address this by
placing the prop center line and the strake in the same plane, or at least
much closer than the Vari. Granted this is much preferable. Unfortunately,
the prop is also closer to the trailing edge of the wing in the Long EZ. One
of the reasons that I like the Vari is the greater distance between the
trailing edge and the prop. I placed the prop in the same location as the 8
inch prop extension to move it out of the wing wake as far as possible. The
airfoil on the Long is I understand superior to the Vari. Also the anhedral
is unnecessary with ailerons on the wings. I built this model when I was
intending to construct a Vari with a single rotor engine. Since then I have
decided to go with the two rotor and a Long EZ (I figure Herb Sanders has
had experience with both, and he recommends the Long, so why argue) The main
thing I was trying to illustrate with this model is that the base drag issue
can be addressed with a liquid cooled engine without a large increase in
frontal area. Also the use of an ejector type exhaust for ground cooling and
max efficiency.

I placed these pictures on this newsletter to get some feedback from some of
the aerodynamics types. Please feel free to criticize or comment on the
design.

Monty

 
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