Abstract: A gas turbine engine includes a buffer system that can communicate buffer supply air to a portion of the gas turbine engine. The buffer system can include a first circuit and a second circuit. The first circuit selects between a first bleed air supply having a first pressure and a second bleed air supply having a second pressure that is greater than the first pressure to render a first buffer supply air having an intermediate pressure. The second circuit selects between a third bleed air supply and a fourth bleed air supply to communicate a second buffer supply air.

Abstract: A gas turbine engine includes a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, a fan section configured to be driven by the turbine section via a geared architecture, and a buffer system that communicates buffer air to a portion of the gas turbine engine. The buffer system includes a first circuit configured to selectively mix a first bleed air supply having a first pressure and a second bleed air supply having a second pressure that is greater than the first pressure to provide a first buffer supply air having an intermediate pressure compared to the first pressure and the second pressure.

Abstract: A gas turbine engine includes a buffer system that includes a first circuit and a second circuit. The first circuit can communicate a first buffer supply air to a first portion of the gas turbine engine and the second circuit can communicate a second buffer supply air to a second portion of the gas turbine engine.

Abstract: A gas turbine engine includes a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, and a buffer system. The buffer system can include a first circuit that supplies a first buffer supply air and a second circuit that supplies a second buffer supply air. The first circuit can include a first bleed air supply a second bleed air supply and at least one of an ejector and a valve. The second circuit can include a third bleed air supply, a fourth bleed air supply and at least one of an ejector and a valve.

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 buffer supply air to a portion of the gas turbine engine. The buffer system can include a first circuit and a second circuit. The first circuit selects between a first bleed air supply having a first pressure and a second bleed air supply having a second pressure that is greater than the first pressure to render a first buffer supply air having an intermediate pressure. The second circuit selects between a third bleed air supply and a fourth bleed air supply to communicate a second buffer supply air.

Abstract: A gas turbine engine includes a first zone and a second zone downstream from the first zone. A buffer system can communicate a buffer cooling air to at least the first zone. A bleed source can communicate a bleed air to the second zone.

Abstract: A gas turbine engine includes a buffer system. The buffer system can include a first bleed air supply and a conditioning device that conditions the first bleed air supply to render the buffer supply air at an acceptable temperature to anti-ice the hardware of said fan section.

Abstract: A gas turbine engine includes a buffer system that includes a first circuit and a second circuit. The first circuit can communicate a first buffer supply air to a first portion of the gas turbine engine and the second circuit can communicate a second buffer supply air to a second portion of the gas turbine engine.

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 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 has a thrust balance chamber defined between a static housing and a rotating component. The thrust balance chamber is sealed by a first non-contact seal at a radially inner location and a second non-contact seal at a radially outer location.

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: A stator assembly 46 for an axial flow rotary machine 10 is disclosed. Various construction details which increase the efficiency of the machine are developed. In one embodiment, the machine includes a circumferentially continuous structural outer case and a circumferentially continuous inner case which is a pressure vessel for the working medium flow path.

Abstract: The clearance between the outer air seal of a gas turbine engine and the tip of the turbine rotor is controlled by selectively turning on and off or modulating the cool air supply which is directed in proximity to the air seal supporting structure so as to control its thermal growth. The cooling causes shrinkage thereby holding the clearance low and effectively reducing fuel consumption.

Abstract: A reduction of the opening of the clearance between the outer air seal secured to the case of a turbo-fan engine and the tip of the turbine buckets is obtained by selectively turning on and off or modulating the cool air supply. The cool air is bled from the fan discharge duct and is directed externally of the engine case adjacent the seal. Circumferentially mounted spray bars are axially spaced to fit juxtaposed to the annular flanges extending from the engine case and carry a plurality of holes judiciously located to direct the flow of cool air to impinge on the side walls of the flanges to effectuate shrinkage of the case.