"The Non Return Valve Is One Way"
Not so. The function of the valve is to prevent "backflow" of the Fuel once it has passed the valve on its way to the Engine. The Valve sleeve moves in two directions, with flow (and against a spring), and versus flow, with the aid of the spring and the "backflow" of the Fuel, when it closes and prevents Fuel return. The mechanical "stop" can stall in any position, while transiting in either direction, vibrate (resonate) and completely stop Fuel entry into the system. All that is required (unlikely) is sufficient tuned energy to overcome the normal working parameters of the device.
I think some folks are visualizing the dynamic A/C system on short final without considering (perhaps) the level of energy and activity involved in landing 200 tons of incredibly powerful A/C full of PE and engines capable of lifting same. I remember my first experience watching the debut of PanAms first 747 in Honolulu. Relaxing on the beach at Sandy, about two miles from departure end, the A/C lumbered into the air "slowly". What dazzled everyone present was the sound. Everything shook from that spooky rumbling earthquake noise from the fans. the sand was vibrating on the beach.
Each of the RR engines has a fan that is probably too big to fit in one's garage, a device that can move air at a prodigious rate. Imagine each fan straining for purchase at full go, each Blade passing within a foot of the circular Fuel line around the shroud, inches from the Heat exchanger, and trying to disintegrate the HP pump. Feedback? The cold viscous Fuel in the Manifold has to resist carrying that energy throughout the system and still maintain flow within safe parameters. Resonance is definitely possible, and could easily occur given the right links in the chain. IMO.
In opposition people merely say, "Well, it never happened before."
Airfoil
"Ram". Resonance doesn't involve alot of "oscillation" My picture of Resonating fluid is a stalled stand (head), vibrating, rather asymmetrically relative to the "container". John Green might help us here.
Last edited by airfoilmod; 17th June 2008 at 14:28.