tuft testing

Corky Scott wrote in message
Sid, I hope that there are some other scoops somewhere besides the two
I see on top of the airplane. From what I've read over the years if
the two scoops I see are it for cooling, there are two really glaring
problems. 1. Naca scoops are really marginal for engine cooling
intakes, this is something that has been known for many years. 2.
Naca scoops do not work when placed in a low pressure region of the
fuselage. Your two scoops are on the downside of the rear of the
fuselage and for sure are in a low pressure area.

What works? Pitot type scoops placed in an area of positive pressure,
or out in the free air stream ala P-51 Mustang.

But if you have pitot type scoops on the belly of your airplane,
nevermind.

Corky Scott

No, there are no other cooling air inlets. The cooling air flows down
thru the pressure cowling, down thru the cylinders, and exits out the
back around the prop spinner.
This photo shows a rear, in-flight view. The small, dark object on
the bottom cowling is the left exhaust

http://img96.exs.cx/img96/5820/Velocityinflight.jpg

This Velocity was one of the earlier versions (early '90s). The
builder/previous owner told me that this was the third attempt...
The first (IRRC) was pitot type scoops on the bottom cowling. Then
pitot type scoops on the bottom of the strakes a few inches outboard
of the bottom cowling with internal ductwork (about 2 1/2 id) piping
the air into the engine compartment. Finally, apparently the Velocity
people came up with this current design and the plane was retrofitted
shortly before I bought it.

Sid