Abstract:
A gas turbine engine includes a fan section that includes a fan rotatable about an axis of rotation of the gas turbine engine. A speed reduction device is connected to the fan. The speed reduction device includes a star drive gear system with a star gear ratio of at least 1.5. A bypass ratio is greater than about 11.0.
Abstract:
A gas turbine engine includes a fan with a plurality of fan blades rotatable about an axis, and a compressor section that includes at least first and second compressor sections. An average exit temperature of the compressor section is between about 1000° F. and about 1500° F. The engine also includes a combustor that is in fluid communication with the compressor section, and a turbine section that is in fluid communication with the combustor. A geared architecture is driven by the turbine section for rotating the fan about the axis.
Abstract:
A gas turbine engine includes a fan section including a fan that is rotatable about an axis. A speed reduction device is connected to the fan. The speed reduction device includes a star drive gear system with a star gear ratio of at least 1.5. A bypass ratio is greater than about 11.0.
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. The pressure ratio across the first compressor is greater than or equal to about 7.
Abstract:
A gas turbine engine is typically comprised of a fan stage, multiple compressor stages, and multiple turbine stages. These stages are made up of alternating rotating blade rows and static vane rows. The total number of blades and vanes is the airfoil count. An overall pressure ratio is greater than 30. A bypass ratio is greater than 8. A stage ratio is the product of the bypass ratio and the overall pressure ratio divided by the number of stages. An airfoil ratio is that product divided by the airfoil count. The stage ratio is greater than or equal to 22 and/or the airfoil ratio is greater than or equal to 0.12.
Abstract:
A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a fan section including a fan rotatable about an axis and a speed reduction device in communication with the fan. The speed reduction device includes a star drive gear system with a star gear ratio of at least 1.5. A fan blade tip speed of the fan is less than 1400 fps.
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. The pressure ratio across the second compressor section is greater than about 7.
Abstract:
A gas turbine engine includes a housing includes an inlet case and an intermediate case that respectively provide an inlet case flow path and an intermediate case flow path. A rotor is connected to the hub and supports a compressor section. The geared architecture includes an epicyclic gear train. A fan is rotationally driven by the geared architecture. First and second bearings support the shaft relative to the intermediate case and the inlet case, respectively. The radially inner boundary of the core inlet is at a location of a core inlet stator and the radially inner boundary of the compressor section inlet is at a location of the first stage low-pressure compressor rotor.
Abstract:
In one exemplary embodiment, a gas turbine engine includes a fan section having a fan with a low corrected fan tip speed less than 1400 ft/sec. A bypass ratio is greater than 11.0 and less than 22.0. A fan pressure ratio is less than 1.48. A speed reduction device includes a gear system with a gear ratio of at least 2.6 and less than or equal to 4.1. A low pressure turbine including three stages and a high pressure turbine including two stages. The low pressure turbine includes at least one rotor constrained by a first stress level. At least one of a plurality of fan blades is constrained by a second stress level and has a fan tip speed boundary condition. The gear ratio is configured such that the at least one fan blade does not exceed the fan tip speed boundary condition or the second stress level.
Abstract:
A ratio of an outer diameter of a fan hub at a leading edge of the blades to an outer tip diameter of the blades at the leading edge is greater than or equal to about 0.24 and less than or equal to about 0.38. The fan tip diameter is greater than or equal to about 84 inches (213.36 centimeters) and a fan tip speed is less than or equal to about 1050 ft/second (320.04 meters/second). A bypass ratio, a gear ratio and an AN2 value are also claimed. The fan drive turbine has between three and six stages.