Going full circle to the start of thread where I remarked that Concorde 'sucked its way through the air' it obviosuly wasn't too far from fact.
Still when one thinks about thrust one imagines what happens in subsonic flight where the propelling force comes from prop-wash,
jet-wash or down-wash in the case of a wing. All these involve momentum exchange iaw Newton to produce thrust.
I suppose part of the cognitive problem wjhen talking about 'intake' produced thrust is that it sounds a bit like 'one hand clapping' as one looses clarity of the momentum exchange process which is a prerequisit for thrust generation.
I suppose that the satisfactory explanation one was hoping to get was one that related the deceleration/compression of the incoming flow in the intake to a momentum exchange process that ledi to thrust.
There are of course other propelling forces that do not rely on momentum exchange such as tyre traction which requires friction and the dreaded drag forces produced by viscous friction.
Last edited by b377; 13th Sep 2010 at 14:37.