Jerry Hey wrote:

Paul wrote

Scoops like that don't work Jerry. If they did there would be no
need of boundary layer air bleeds like are found on all airplanes
built since World War two. What happened to the tunnel idea?

The pictures of air bleeds that I have seen seem to have been very
shallow perhaps only a quater of an inch or so.  How thick is the
boundary layer under the belly ?  Seems like a scoop hanging down
below this level  would be in clean air, and it would generate
considerable pressure to enter the inlet.  Like I was very careful to
say, these are just aluminum sheet metal that can be discarded and
new versions created fairly easily.  Perhaps in the end, I will have
just a scoop with an airbleed.  It would be the easiest of all
configurations to build.  How deep should the air bleed be?.   Jerry

I don't know. It is hard for me to say. That is why I wanted you
to do the velocity rake trick. Here is the old message.

"You are in the boundary layer.
Make a velocity rake which is a series of six simple pitot tubes
spaced 3/4 of an inch apart and measure the pressures below the fuselage
with this plastic tube water manometer and tell me what they are. 
Use the cockpit for a static reference pressure. The lowest pitot 
tube in the velocity  rake should be about four inches below the skin. 
The numbers will be the difference in the height of the two water 
columns in inches. Fill the U tubes about half way up. Drip irrigation
tees and angle connectors are available in the garden shop to make 
a water manometer. PL"

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.
ACRE NL web site.
http://home.earthlink.net/~rotaryeng/            http://www.linux.org