Abstract: A gas generator has at least one compressor rotor, at least one gas generator turbine rotor and a combustion section. A fan drive turbine is positioned downstream of a path of the products of combustion having passed over the at least one gas generator turbine rotor. The fan drive turbine drives a shaft and the shaft engages gears to drive at least three fan rotors.

Abstract: A gas turbine engine includes, among other things, a fan section, a core engine, a bypass passage, a bypass ratio defined as the volume of air passing into the bypass passage compared to the volume of air passing into the core engine, the bypass ratio being greater than or equal to 10 at cruise power, and a low fan pressure ratio of less than 1.45 measured across a fan blade alone. A gear arrangement drives the fan section. A compressor section includes both a low pressure compressor and a high pressure compressor. A guide vane includes a forward attachment, the forward attachment positioned aft of a plumbing connection area. A turbine section drives the gear arrangement, and may have a low pressure turbine with a low pressure turbine pressure ratio greater than 5:1, and a two stage high pressure turbine.

Abstract: A gas turbine engine includes, among other things, a fan section, a core engine, a bypass passage, and a bypass ratio defined as the volume of air passing into the bypass passage compared to the volume of air passing into the core engine, the bypass ratio being greater than 8 at cruise power. A gear arrangement drives the fan section. A guide vane includes a forward attachment, the forward attachment positioned aft of a plumbing connection area. A compressor section includes both a first compressor and a second compressor. A lubrication system and a compressed air system are in fluid communication with the gear arrangement. A turbine section drives the gear arrangement, and includes a low pressure turbine. An overall pressure ratio is provided by the combination of a pressure ratio across the first compressor and a pressure ratio across the second compressor, and greater than about 50, measured at sea level and at a static, full-rated takeoff power.

Abstract: A gas turbine engine according to the present disclosure includes a first compressor and a first turbine for driving the first compressor. A core section includes a second compressor and a second turbine for driving the second compressor. A third turbine is arranged fluidly downstream of the first turbine and the second turbine and configured to drive a power take-off. A first duct system is arranged fluidly between the low-pressure compressor and the core section. The first duct system is arranged to reverse fluid flow before entry into the core section.

Abstract: A recuperated gas turbine engine includes an engine core that has a compressor section, a combustor section, and a turbine section. An exhaust duct is located downstream of the turbine section for receiving a hot turbine exhaust stream from the turbine section. The exhaust duct includes a heat exchanger and a temperature-control module upstream of the heat exchanger. A compressor bleed line leads from the compressor section into the heat exchanger and a compressor return line leads from the heat exchanger into the engine core upstream of the combustor section. The compressor bleed line is operable to selectively feed compressed air to the heat exchanger, and the temperature-control module is operable to selectively modulate at least one of temperature and flow of the hot turbine exhaust stream with respect to the heat exchanger.

Abstract: A compressor section of a gas turbine engine includes a bleed port having a flow splitter therein so as to define a downstream bleed channel having a downstream inlet and an upstream bleed channel having an upstream inlet that is positioned radially outward from the downstream inlet.

Abstract: A gas generator for a reverse core engine propulsion system has a variable cycle intake for the gas generator, which variable cycle intake includes a duct system. The duct system is configured for being selectively disposed in a first position and a second position, wherein free stream air is fed to the gas generator when in the first position, and fan stream air is fed to the gas generator when in the second position.

Abstract: A gas turbine engine includes, among other things, a fan section, a core engine, a bypass passage, and a bypass ratio defined as the volume of air passing into the bypass passage compared to the volume of air passing into the core engine, the bypass ratio being greater than or equal to about 8 at cruise power. A gear arrangement is configured to drive the fan section. A compressor section includes both a first compressor section and a second compressor section. A turbine section is configured to drive the gear arrangement, and may have a low pressure turbine with four stages and a low pressure turbine pressure ratio greater than about 5:1, and a high pressure turbine with two stages. An overall pressure ratio is provided by the combination of a pressure ratio across the first compressor section and a pressure ratio across the second compressor section, and greater than about 40, measured at sea level and at a static, full-rated takeoff power.

Abstract: A gas turbine engine system includes a fan section, a low pressure compressor section downstream of the fan section, a first engine core downstream from the low pressure compressor section, a second engine core downstream from the low pressure compressor section, and a flowpath control mechanism configured to selectively restrict fluid flow through the second engine core. The first engine core includes a first engine core compressor section, a first engine core combustor downstream of the first engine core compressor section, and a first engine core turbine section downstream of the first engine core combustor. The second engine core includes a second engine core compressor section, a second engine core combustor downstream of the second engine core compressor section, and a second engine core turbine section downstream of the second engine core combustor.

Abstract: A turbofan engine has an engine case and a gaspath through the engine case. A fan has a circumferential array of fan blades. The engine further has a compressor, a combustor, a gas generating turbine, and a low pressure turbine section. A speed reduction mechanism couples the low pressure turbine section to the fan. A bypass area ratio is greater than about 6.0. The low pressure turbine section airfoil count to bypass area ratio is below about 170.

Abstract: A gas turbine engine has a fan section, a gear arrangement configured to drive the fan section, a compressor section, including both a low pressure compressor section and a high pressure compressor section. A turbine section is configured to drive the compressor section and the gear arrangement. An overall pressure ratio provided by the combination of a pressure ratio across the low pressure compressor section and a pressure ratio across the high pressure compressor section is greater than about 35. The pressure ratio across a first of the low and high pressure compressor sections is between about 3 and about 8. The pressure ratio across a second of the low and high pressure compressor sections is between about 7 and about 15. The fan is configured to deliver a portion of air into the compressor section, and a portion of air into a bypass duct.

Abstract: A gas generator has at least one compressor rotor, at least one gas generator turbine rotor and a combustion section. A fan drive turbine is positioned downstream of a path of the products of combustion having passed over the at least one gas generator turbine rotor. The fan drive turbine drives a shaft and the shaft engages gears to drive at least three fan rotors.

Abstract: A turbofan engine has an engine case and a gaspath through the engine case. A fan has a circumferential array of fan blades. The engine further has a compressor, a combustor, a gas generating turbine, and a low pressure turbine section. A speed reduction mechanism couples the low pressure turbine section to the fan. A bypass area ratio is greater than about 6.0. The low pressure turbine section airfoil count to bypass area ratio ratio is below about 170.

Abstract: A separate propulsion unit incorporating a free turbine and a fan receives gases from a plurality of core engines. The core engines each include a compressor, a turbine and a combustion section. The core engines in combination pass gases across the free turbine. A method is also disclosed.

Abstract: A turbofan engine is disclosed and includes a fan and a compressor in communication with the fan section, a combustor, a turbine and a speed reduction mechanism coupled to the fan and rotatable by the turbine. The turbine includes a first turbine section that includes three or more stages and a second turbine section that includes at least two stages. A ratio of airfoils in the first turbine section to a bypass area is less than about 170.

Abstract: A turbofan engine has an engine case and a gaspath through the engine case. A fan has a circumferential array of fan blades. The engine further has a compressor, a combustor, a gas generating turbine, and a low pressure turbine section. A speed reduction mechanism couples the low pressure turbine section to the fan. A bypass area ratio is greater than about 6.0. The low pressure turbine section airfoil count to bypass area ratio is below about 170.

Abstract: A gas generator for a reverse core engine propulsion system has a variable cycle intake for the gas generator, which variable cycle intake includes a duct system. The duct system is configured for being selectively disposed in a first position and a second position, wherein free stream air is fed to the gas generator when in the first position, and fan stream air is fed to the gas generator when in the second position.

Abstract: A turbofan engine is disclosed and includes a fan and a compressor in communication with the fan section, a combustor, a turbine and a speed reduction mechanism coupled to the fan and rotatable by the turbine. The turbine includes a first turbine section that includes three or more stages and a second turbine section that includes at least two stages. A ratio of airfoils in the first turbine section to a bypass area is less than about 170.

Abstract: A gas turbine engine has a fan section, including a fan, a gear arrangement configured to drive the fan section, and a compressor section, including both a first compressor and a second compressor. A turbine section is configured to drive the compressor section and the gear arrangement. An overall pressure ratio is provided by the combination of the first compressor and the second compressor, with the overall pressure ratio being greater than or equal to about 35. The fan is configured to deliver a portion of air into the compressor section, and a portion of air into a bypass duct. A bypass ratio, which is defined as a volume of air passing to the bypass duct compared to a volume of air passing into the compressor section, is greater than or equal to about 8.

Abstract: A method of designing a gas turbine engine includes providing a fan section including a fan; driving the fan section via a gear arrangement; providing a compressor section, including both a first compressor and a second compressor; and driving the compressor section and the gear arrangement via a turbine section. An overall pressure ratio, being provided by the combination of a pressure ratio across the first compressor and a pressure ratio across the second compressor, is greater than or equal to about 35. The pressure ratio across the first compressor is greater than or equal to about 7.