Method and system to ensure full oil tubes after gas turbine engine shutdown

A gas turbine engine comprising:

• a bearing compartment having an inlet and an outlet;
• a reservoir;
• a supply line that splits into a supply conduit and a reservoir conduit that are fluidly parallel to one another for a length, the reservoir conduit fluidly rejoining the supply conduit at a junction, the supply conduit fluidly connected to the inlet, and the reservoir conduit including a flow restrictor upstream from the junction;
• an anti-siphon line fluidly interconnected to the supply line and the reservoir, and a flow restriction separating the anti-siphon line from the supply line;
• a main pump fluidly connected to the supply line and configured to supply a lubricant to the bearing compartment through the supply line and supply and reservoir conduits in an operating state, the main pump having a non-operating state in which the reservoir conduit is configured to more slowly refill the supply conduit through the flow restrictor with the reservoir conduit than the lubricant can evacuate from the supply conduit, the inlet and the outlet are respectively provided on high and low pressure sides, and a lubricant pressure differential between the high and low pressure sides is configured to evacuate the supply conduit with the main pump in the non-operating state;
• a scavenger pump fluidly connected to the reservoir and the outlet respectively by a return line and a scavenge line;
• and
• wherein the supply conduit includes a U-shaped portion gravitationally below the junction in a normal engine operating condition, the U-shaped portion includes a flow meter downstream from the junction, the U-shaped portion is gravitationally below the bearing compartment in the normal engine operating condition, the U-shaped portion includes legs that are filled by the reservoir conduit with the main pump in the non-operating condition, the reservoir conduit is gravitationally above the junction in the normal engine operating condition, the supply split into the supply and reservoir conduits is gravitationally above the junction in the normal engine operating condition, and the main pump is gravitationally below the U-shaped portion and the reservoir in the normal engine operating condition.