Abstract:
A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a performance quantity ratio between about 0.8 and about 1.5.
Abstract:
A gas turbine engine includes a very high speed low pressure turbine such that a quantity defined by the exit area of the low pressure turbine multiplied by the square of the low pressure turbine rotational speed compared to the same parameters for the high pressure turbine is at a ratio between about 0.5 and about 1.5.
Abstract:
A gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan rotor. Aspects of the gear system are provided with some flexibility. The fan drive turbine has a first exit area and rotates at a first speed. A second turbine section has a second exit area and rotates at a second speed, which is faster than said first speed. A performance quantity can be defined for both turbine sections as the products of the respective areas and respective speeds squared. A performance quantity ratio of the performance quantity for the fan drive turbine to the performance quantity for the second turbine section is relatively high.
Abstract:
A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. A speed reduction device such as an epicyclical gear assembly may be utilized to drive the fan section such that the fan section may rotate at a speed different than the turbine section so as to increase the overall propulsive efficiency of the engine. In such engine architectures, a shaft driven by one of the turbine sections provides an input to the epicyclical gear assembly that drives the fan section at a speed different than the turbine section such that both the turbine section and the fan section can rotate at closer to optimal speeds providing increased performance attributes and performance by desirable combinations of the disclosed features of the various components of the described and disclosed gas turbine engine.
Abstract:
In accordance with one aspect of the disclosure, a stream diverter for a gas turbine engine is disclosed. The stream diverter may include a first air duct, a second air duct, a third air duct, and a door operatively associated with the second and third air ducts of the gas turbine engine. The door may have at least an open position allowing air from the second air duct to flow into the third air duct and a closed position preventing air from flowing between the ducts.
Abstract:
A method of controlling a variable area gas turbine engine includes, running the variable area turbine engine at initial settings, monitoring two sets of operating parameters of the engine at the initial settings, and deducing vane angles of adjustable vanes without directly measuring the vane angles from mapped data of the two sets of operating parameters of a similar engine operated while direct vane angle measurements were being recorded.
Abstract:
A gas turbine engine section includes a plurality of spaced rotor stages, with a static guide vane intermediate the spaced rotor stages. The static guide vane provides swirl into air passing toward a downstream one of the spaced rotor stages, and an outer housing surrounding the spaced rotor stages. A diverter diverts a portion of air radially outwardly through the outer housing, and across at least one heat exchanger. The diverted air passes back into a duct radially inwardly through the outer housing, and is exhausted toward the downstream one of the spaced rotor stages.
Abstract:
A gas turbine engine according to an example of the present disclosure includes, among other things, a fan section, and a compressor section including at least a first compressor section and a second compressor section. A power ratio is provided by the combination of the first compressor section and the second compressor section. A method of design a gas turbine engine is also disclosed.
Abstract:
A drive architecture comprises a rotor and a gearbox for driving the rotor. A pair of input gears provides rotational drive to the gearbox. A first recuperative cycle engine drives one of the pair of gears and a second engine drives the other of the pair of gears. The first recuperative cycle engine and the second engine are both gas turbine engines. A power takeoff from a drive shaft of the second engine supplies rotational drive to drive at least one component in the first recuperative cycle drive.
Abstract:
A gas turbine engine includes a combustor. A turbine section is in fluid communication with the combustor. The turbine section includes a fan drive turbine and a second turbine. The fan drive turbine includes a plurality of turbine rotors. A fan includes a plurality of blades rotatable about an axis and a ratio between the number of fan blades and the number of fan drive turbine rotors is between about 2.5 and about 8.5. A speed change system is driven by the fan drive turbine for rotating the fan about the axis. The fan drive turbine has a first exit area at a first exit point and rotates at a first speed. The second turbine section has a second exit area at a second exit point and rotates at a second speed, which is faster than the first speed. A first performance quantity is defined as the product of the first speed squared and the first area. A second performance quantity is defined as the product of the second speed squared and the second area. A performance ratio of the first performance quantity to the second performance quantity is between about 0.5 and about 1.5.