Originally Posted by SNS3Guppy
These magic fans, spaced the full span of the wing, will produce thrust if attached to the airframe, if producing enough thrust to produce lift.
Guppy, I agree with most of what you write, but here there might just be a slight misunderstanding. You are quite right if the "wind" over the airfoil is generated by propellers or fans mounted in front of the wing. But that's not how I interpreted PBL's hypothetical proposition:
Originally Posted by PBL
Now, does it matter where this "relative wind" comes from? No. Just that it is present.
What if the source of the "wind" is a large reservoir of compressed air?
it's enough to address the salient point that ram drag, and not reverse gas flow, accounts for the retarding force in reverse thrust
Why not both?
regards,
HN39