Russell Kent wrote:

...if the velocity of the air in the duct is not a
significant fraction (like 70%) of the free airstream velocity, then the
duct "looks" like a wart on the fuselage, and the free airstream flows
around it.

Interesting. Intuitively that makes sense, since there's
not a lot of ram-air pressure into the inlet. Still, even
axial-flow compressors *can* generate significant back
pressure and inlet spillage, especially at 'high' speed
and low power settings. I wonder what the stall margin
is like on a NACA-inlet-fed jet.

Dave 'surge' Hyde

Inspection Sunday!