A gas turbine engine comprises bearing(s). A structure supporting the bearing defines a bearing cavity surrounding the at least one bearing, an ambient chamber and an intermediate chamber having a portion between the bearing cavity and the ambient chamber, with at least one wall forming a passage from the bearing cavity to the ambient chamber and through the portion of the intermediate chamber. A tube is received in the passage and having a first end open to the bearing cavity and a second end open to the ambient chamber, the second end adapted to be connected to a conduit for fluid communication between the bearing cavity and the through the tube, wherein a portion of or near the first end of the tube is sealingly joined to the at least one wall, and the second end of the tube contacts the at least one wall and is free to move relative to the at least one wall.

The present application provides a micro-mixer fuel plenum for mixing a flow of fuel and a flow of air in a combustor. The micro-mixing fuel plenum may include an outer barrel and a number of mixing tubes positioned within the outer barrel. The mixing tubes may include one or more heat transfer features thereon.

A method of manufacturing a nested combustor liner includes manufacturing a nested combustor liner into a green state including a plurality of annular interior walls radially adjacent to one another and circumferentially surrounding an exhaust duct aperture and a plurality of annular exterior walls radially adjacent to one another and radially spaced apart from and circumferentially surrounding the plurality of annular interior walls and an ignitor wall attached to a first annular interior wall at a first interior end, extending radially toward and attached to a first annular exterior wall at a first exterior end. The method includes assembling the plurality of annular interior walls and the plurality of annular exterior walls, forming an assembled combustor liner. The method includes densifying the assembled combustor liner.

A gas turbine engine fuel supply system can include a fuel delivery system, a thermal management system, a fuel manifold, and one or more sensors that identify one or more fuel parameters. A fuel control system can be controlled to adjust one or more parameters of the fuel based on data received from the sensors.

A method of manufacturing a nested combustor liner includes manufacturing a nested combustor liner into a green state including a plurality of annular interior walls radially adjacent to one another and circumferentially surrounding an exhaust duct aperture and a plurality of annular exterior walls radially adjacent to one another and radially spaced apart from and circumferentially surrounding the plurality of annular interior walls and an ignitor wall attached to a first annular interior wall at a first interior end, extending radially toward and attached to a first annular exterior wall at a first exterior end. The method includes assembling the plurality of annular interior walls and the plurality of annular exterior walls, forming an assembled combustor liner. The method includes densifying the assembled combustor liner.

A method of manufacturing a nested combustor liner includes manufacturing a nested combustor liner into a green state including a plurality of annular interior walls radially adjacent to one another and circumferentially surrounding an exhaust duct aperture and a plurality of annular exterior walls radially adjacent to one another and radially spaced apart from and circumferentially surrounding the plurality of annular interior walls and an ignitor wall attached to a first annular interior wall at a first interior end, extending radially toward and attached to a first annular exterior wall at a first exterior end. The method includes assembling the plurality of annular interior walls and the plurality of annular exterior walls, forming an assembled combustor liner. The method includes densifying the assembled combustor liner.