Abstract:
A bowed rotor start mitigation system for a gas turbine engine is provided. The bow rotor start mitigation system includes a controller operable to receive a speed input indicative of a rotor speed of the gas turbine engine and a measured temperature of the gas turbine engine. The controller is further operable to drive motoring of the gas turbine engine by oscillating the rotor speed within a motoring band for a motoring time based on the measured temperature when a start sequence of the gas turbine engine is initiated.
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 defined 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 between 0.5 and 1.5.
Abstract:
A system is provided for a turbine engine. This turbine engine system includes a rotating assembly, a bearing and a lubrication system. The bearing is configured with the rotating assembly. The lubrication system is configured to lubricate the bearing. The lubrication system includes a lubricant pump and a lubricant reservoir. The lubricant pump is mechanically coupled with and driven by the rotating assembly. The lubricant pump is configured with the lubricant reservoir so as to be at least partially submersed in lubricant contained within the lubricant reservoir.
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 assembly for an aircraft includes a fan section delivering air into a main compressor section. The main compressor section includes a first compressor section and a second compressor section operating at a higher pressure than the first compressor section. The main compressor section compresses air and delivers air into a combustion section where the air is mixed with fuel and ignited to generate products of combustion that are passed over a turbine section to drive the fan section and main compressor sections. An environmental control system includes a low pressure tap at a location on the first compressor section of the main compressor section. The low pressure tap communicates airflow to a first passage leading to a downstream outlet. A compressor is driven by an electric motor. A combined outlet intermixes airflow from the first passage and from the compressor driven by the electric motor and passes the airflow downstream to be delivered to an aircraft use. An environmental control system is also disclosed.
Abstract:
An assembly is provided for rotational equipment such as a gas turbine engine for an aircraft propulsion system. This assembly includes a stator, a rotor and a seal assembly. The rotor extends axially along a centerline. The rotor includes a linkage, a first rotor disk, and a second rotor disk. The linkage extends axially from the first rotor disk to the second rotor disk. The linkage is removably attached to the second rotor disk. The seal assembly is configured for sealing a gap radially between the stator and the linkage. The seal assembly includes a hydrostatic non-contact seal.
Abstract:
An assembly is provided for rotational equipment. The assembly includes a circumferentially segmented stator and a rotor radially within the stator. The assembly also includes a seal assembly configured for substantially sealing a gap radially between the stator and the rotor. The seal assembly includes a carrier and a non-contact seal seated with the carrier. The carrier includes a plurality of discrete carrier segments circumferentially arranged around the non-contact seal.
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.
Abstract:
A turbofan engine includes a fan section including a fan blade having a leading edge and hub to tip ratio of less than about 0.34 and greater than about 0.020 measured at the leading edge and a speed change mechanism with gear ratio greater than about 2.6 to 1. A first compression section includes a last blade trailing edge radial tip length that is greater than about 67% of the radial tip length of a leading edge of a first stage of the first compression section. A second compression section includes a last blade trailing edge radial tip length that is greater than about 57% of a radial tip length of a leading edge of a first stage of the first compression section.
Abstract:
A gas turbine engine has an upstream compressor having an upstream entrance area leading into a first vane upstream of the upstream compressor. A downstream compressor has an exit area at a leading edge of an exit vane for the downstream compressor. The entrance area divided by the exit area is greater than or equal to 13.8 and less than or equal to 15.3.