I've been having a nap, but I'm back.
Alosaurus, the hosepipe analogy stands. Forget the water if that causes confusion....Consider a hose, full of air.
Lu, I understand part of what you're saying, but to use your own example, a ramjet is indeed open at both ends, and yes "The Jet Engine" by Rolls-Royce does say that a ramjet, which is open at both ends, does work. Let's not compare credentials, because I think that the authors of that book have bigger ones than you, and I don't even want to talk about mine
Read the book for yourself!
Also, while you obviously know quite a bit about rocket engines, you are comparing apples with oranges when you say that the combustor cans develop the force in a turbine. The combustor can/annulus is a very open framework whose purpose is to promote efficient combustion. It is not a pressure vessel. It sits inside the combustor case, which is a pressure vessel, but which is also open at both ends. The compressor in front of it takes the place of the ram effect and subsequent diffusion that occurs in the pure ram jet.
I'm still interested in where the force is actually transmitted. Is there anyone out there?