ORIGINAL: Square Nozzle
ORIGINAL: BaldEagel
Consider the turbine wheel as a prop, does not matter if its in front or behind the C of G the thrust line stays the same whether pushing or pulling the reaction is also still the same.
If the turbine wheel and thrust line is pointing down at the rear, the reaction is for the nose of the airframe to Lower, now put that same thrust line on the nose of the airframe, still pointing down and still the reaction is for the nose of the airfame to lower, but the prop in conventional terms is pointing towards the sky, so its up thrust in conventional teminology with tractor propulsion which is the nomuculture.
Mike
Mike, if I read you correctly then I disagree with your thrust vector analysis. I agree that the nozzle facing down with the engine at the rear of the plane will push the nose down because the plane is rotating about the CG. If I keep that same thrust line and move the engine forward of the CG the nose will rise.
Only if you turn the prop and thrust direction around. think about it again without moving the prop or altering the thrust direction, see Xairflyer's explanation post 25 he has explaind it better.
Efflux has been mentioned in several responses. Someone please explain to me what efflux is.
Efflux is the high velocity air exiting the turbine exhaust. I think it refers to the effect on the horizontal stab with the high speed nozzle discharge air passing under the stab and elevator. The result, high speed - low pressure air below the stab and relatively slow speed lower pressure air moving above the stab forces the stab down.