Originally Posted by Keith.Williams
Could it be that the supersonic intake produces thrust in an indirect way...
As said before, there's nothing "indirect" about it.
The forces acting on the complete intake structure, which finally are part of the forces that propel the aircraft, are acting
forward.
... rather like the convergent propelling nozzle?
The force on the propelling nozzle acts rearwards, but the overall effect of the nozzle is to increase the total thrust. But the extra thrust does not act directly on the propelling nozzle.
You're slightly confusing the issue, because we're now talking about supersonic con-di nozzles, where again the resulting forces on the nozzle structure act
forward.
CJ