Abstract: A gas turbine engine includes a buffer system that communicates a buffer supply air to a portion of the gas turbine engine. The buffer system includes a first bleed air supply having a first pressure, a second bleed air supply having a second pressure that is greater than the first pressure, and a valve that selects between the first bleed air supply and the second bleed air supply to communicate the buffer supply air to the portion of the gas turbine engine.

Abstract: A gas turbine engine includes a buffer system that communicates a buffer cooling air to at least one bearing structure and at least one shaft of the gas turbine engine. The buffer system includes a first bleed air supply and a conditioning device that conditions the first bleed air supply to render the first buffer supply air at an acceptable temperature to pressurize the at least one bearing structure and cool the at least one shaft.

Abstract: A buffer system for a gas turbine engine includes a heat exchanger having a first inlet and outlet and a second inlet and outlet. The first outlet is configured to provide a cooled pressurized fluid. First and second air sources are selectively fluidly coupled to the first inlet. A third air source is fluidly coupled to the second inlet. Multiple fluid-supplied areas are located remotely from one another and are fluidly coupled to the first outlet. The multiple fluid-supplied areas include multiple bearing compartments. A method of providing pressurized air in a gas turbine engine includes selectively providing pressurized air from multiple air sources to a heat exchanger to cool the pressurized air. The cooled pressurized air is distributed to multiple fluid-supplied areas within the gas turbine engine.

Abstract: A gas turbine engine includes a buffer system that can communicate a buffer supply air to a portion of the gas turbine engine. The buffer system includes a first bleed air supply having a first pressure, a second bleed air supply having a second pressure that is greater than the first pressure, and an ejector that selectively augments the first bleed air supply to prepare the buffer supply air for communication to the portion of the gas turbine engine.

Abstract: A gas turbine engine includes a bearing structure mounted to the front center body case structure to rotationally support a shaft driven by a geared architecture. A bearing compartment passage structure is in communication with the bearing structure through a front center body case structure.

Abstract: In one exemplary embodiment, a gas turbine engine includes a turbine and a high pressure compressor. The high pressure compressor includes a last stage having a last stage compressor blade and a last stage vane. The gas turbine engine includes a first flow path through which bleed air flows to the turbine and a second flow path through which air from the last stage of the high pressure compressor flows. The bleed air in the first flow path exchanges heat with a portion of the air in the second flow path in a heat exchanger to cool the air in the second flow path. The cooled air in the second flow path is returned to the high pressure compressor to cool the high pressure compressor.

Abstract: In one exemplary embodiment, a gas turbine engine includes a turbine and a high pressure compressor. The high pressure compressor includes a last stage having a last stage compressor blade and a last stage vane. The gas turbine engine includes a first flow path through which bleed air flows to the turbine and a second flow path through which air from the last stage of the high pressure compressor flows. The bleed air in the first flow path exchanges heat with a portion of the air in the second flow path in a heat exchanger to cool the air in the second flow path. The cooled air in the second flow path is returned to the high pressure compressor to cool the high pressure compressor.

Abstract: In one exemplary embodiment, a gas turbine engine includes a turbine and a high pressure compressor. The high pressure compressor includes a last stage having a last stage compressor blade and a last stage vane. The gas turbine engine includes a first flow path through which bleed air flows to the turbine and a second flow path through which air from the last stage of the high pressure compressor flows. The bleed air in the first flow path exchanges heat with a portion of the air in the second flow path in a heat exchanger to cool the air in the second flow path. The cooled air in the second flow path is returned to the high pressure compressor to cool the high pressure compressor.

Abstract: Self-balancing face seals and gas turbine engine systems involving such seals are provided. In this regard, a representative self-balancing face seal assembly includes: a rotatable seal runner having a first seal runner face and an opposing second seal runner face; a first face seal operative to form a first seal with the first seal runner face, the first face seal being one of a hydrostatic seal and a hydrodynamic seal; and a second face seal operative to form a second seal with the second seal runner face, the first face seal being one of a hydrostatic seal and a hydrodynamic seal.

Abstract: Gas turbine engine systems involving hydrostatic face seals with anti-fouling provisioning are provided. In this regard, a representative turbine assembly for a gas turbine engine comprises: a turbine having a hydrostatic seal; the hydrostatic seal having a seal face, a seal runner, a carrier, and a biasing member; the seal face and the seal runner defining a high-pressure side and a lower-pressure side of the seal; the carrier being operative to position the seal face relative to the seal runner; and the biasing member being located on the lower-pressure side of the seal and being operative to bias the carrier such that interaction of the biasing member and gas pressure across the seal causes the carrier to position the seal face relative to the seal runner.

Abstract: Gas turbine engine systems involving hydrostatic face seals with back-up seals are provided. In this regard, a representative seal assembly for a gas turbine engine includes: a hydrostatic seal having a seal face and a seal runner; and a back-up seal; wherein, in a normal mode of operation of the hydrostatic seal, interaction of the seal face and the seal runner maintains a pressure differential within the gas turbine engine and, in a failure mode of operation of the hydrostatic seal, the back-up seal maintains a pressure differential within the gas turbine engine.

Abstract: Gas turbine engine systems involving hydrostatic face seals with integrated back-up seals are provided. In this regard, a representative seal assembly for a gas turbine engine includes: a stator assembly and a rotor assembly configured to operatively engage each other to form a first seal and a second seal; the first seal being provided by a hydrostatic seal having a seal face and a seal runner; and the second seal being provided by a back-up seal such that responsive to a failure of the first seal, the back-up seal maintains at least a portion of a pressure differential established by the first seal prior to the failure.

Abstract: In one exemplary embodiment, a gas turbine engine includes a turbine and a high pressure compressor. The high pressure compressor includes a last stage having a last stage compressor blade and a last stage vane. The gas turbine engine includes a first flow path through which bleed air flows to the turbine and a second flow path through which air from the last stage of the high pressure compressor flows. The bleed air in the first flow path exchanges heat with a portion of the air in the second flow path in a heat exchanger to cool the air in the second flow path. The cooled air in the second flow path is returned to the high pressure compressor to cool the high pressure compressor.

Abstract: Gas turbine engine systems involving hydrostatic face seals are provided. In this regard, representative compressor assembly for a gas turbine engine includes a compressor having a hydrostatic seal formed by a seal face and a seal runner.

Abstract: Self-balancing face seals and gas turbine engine systems involving such seals are provided. In this regard, a representative self-balancing face seal assembly includes: a rotatable seal runner having a first seal runner face and an opposing second seal runner face; a first face seal operative to form a first seal with the first seal runner face, the first face seal being one of a hydrostatic seal and a hydrodynamic seal; and a second face seal operative to form a second seal with the second seal runner face, the first face seal being one of a hydrostatic seal and a hydrodynamic seal.

Abstract: Gas turbine engine systems involving hydrostatic face seals are provided. In this regard, representative compressor assembly for a gas turbine engine includes a compressor having a hydrostatic seal formed by a seal face and a seal runner.

Abstract: Gas turbine engine systems involving hydrostatic face seals with integrated back-up seals are provided. In this regard, a representative seal assembly for a gas turbine engine includes: a stator assembly and a rotor assembly configured to operatively engage each other to form a first seal and a second seal; the first seal being provided by a hydrostatic seal having a seal face and a seal runner; and the second seal being provided by a back-up seal such that responsive to a failure of the first seal, the back-up seal maintains at least a portion of a pressure differential established by the first seal prior to the failure.

Abstract: Gas turbine engine systems involving hydrostatic face seals are provided. In this regard, representative turbine assembly for a gas turbine engine includes a turbine having a hydrostatic seal formed by a seal face and a seal runner.

Abstract: Gas turbine engine systems involving hydrostatic face seals with anti-fouling provisioning are provided. In this regard, a representative turbine assembly for a gas turbine engine comprises: a turbine having a hydrostatic seal; the hydrostatic seal having a seal face, a seal runner, a carrier, and a biasing member; the seal face and the seal runner defining a high-pressure side and a lower-pressure side of the seal; the carrier being operative to position the seal face relative to the seal runner; and the biasing member being located on the lower-pressure side of the seal and being operative to bias the carrier such that interaction of the biasing member and gas pressure across the seal causes the carrier to position the seal face relative to the seal runner.

Abstract: Gas turbine engine systems involving hydrostatic face seals with back-up seals are provided. In this regard, a representative seal assembly for a gas turbine engine includes: a hydrostatic seal having a seal face and a seal runner; and a back-up seal; wherein, in a normal mode of operation of the hydrostatic seal, interaction of the seal face and the seal runner maintains a pressure differential within the gas turbine engine and, in a failure mode of operation of the hydrostatic seal, the back-up seal maintains a pressure differential within the gas turbine engine.