An aircraft engine, has: a shaft rotatable about a central axis and engaged at an end thereof to a rotatable load via splines; a reference tube extending around the shaft and having a first end secured to the shaft and a second end free relative to the shaft for measuring a deformation of the shaft, the reference tube defining at least one tube aperture; an oil nozzle defining an exit flow axis intersecting the at least one tube aperture, the shaft defining at least one shaft aperture through the shaft, an oil flow path extending from the oil nozzle to the splines; and a drain outlet located radially outwardly of an inlet of the at least one shaft aperture for outputting excess oil out of an annular gap defined between the shaft and the reference tube.

An operation method of a turbine fracturing device and a turbine fracturing device are provided. The turbine fracturing device includes a turbine engine, a speed reducer, a brake mechanism, and a fracturing pump, the method includes: driving, by the turbine engine, the fracturing pump to perform a fracturing operation through the speed reducer so as to keep the fracturing pump in an operating state, the fracturing pump being configured to suck fluid of a first pressure and discharge fluid of a second pressure, the second pressure being greater than the first pressure; and in response to an idling instruction, the turbine engine entering an idling state and triggering a brake operation so as to keep the fracturing pump in a non-operating state.

An operation method of a turbine fracturing device and a turbine fracturing device are provided. The turbine fracturing device includes a turbine engine, a speed reducer, a brake mechanism, and a fracturing pump, the method includes: driving, by the turbine engine, the fracturing pump to perform a fracturing operation through the speed reducer so as to keep the fracturing pump in an operating state, the fracturing pump being configured to suck fluid of a first pressure and discharge fluid of a second pressure, the second pressure being greater than the first pressure; and in response to an idling instruction, the turbine engine entering an idling state and triggering a brake operation so as to keep the fracturing pump in a non-operating state.

A gas turbine engine includes a core housing that includes an inlet case and an intermediate case that respectively provide an inlet case flow path and an intermediate case flow path. A first shaft supports a low pressure compressor section that is arranged axially between the inlet case flow path and the intermediate case flow path. A first bearing supports the first shaft relative to the inlet case. A second bearing supports a second shaft relative to the intermediate case. A low pressure compressor hub is mounted to the first shaft. The low pressure compressor hub extends to the low pressure compressor section between the first bearing and the second bearing.

A gas turbine engine includes a core housing that includes an inlet case and an intermediate case that respectively provide an inlet case flow path and an intermediate case flow path. A first shaft supports a low pressure compressor section that is arranged axially between the inlet case flow path and the intermediate case flow path. A first bearing supports the first shaft relative to the inlet case. A second bearing supports a second shaft relative to the intermediate case. A low pressure compressor hub is mounted to the first shaft. The low pressure compressor hub extends to the low pressure compressor section between the first bearing and the second bearing.

A turbine engine assembly includes: a fan assembly; a turbine coupled to the fan assembly through a gearbox; a stationary component; and an assembly extending between the gearbox and the stationary component to couple the gearbox to the stationary component, wherein the assembly includes at least one vibration-reducing mechanism configured to isolate a vibratory response of the gearbox from the stationary component.

A turbine engine assembly includes: a fan assembly; a turbine coupled to the fan assembly through a gearbox; a stationary component; and an assembly extending between the gearbox and the stationary component to couple the gearbox to the stationary component, wherein the assembly includes at least one vibration-reducing mechanism configured to isolate a vibratory response of the gearbox from the stationary component.

A gas turbine engine includes a propulsor section including a propulsor, a compressor section including a low pressure compressor and a high pressure compressor, a geared architecture, a turbine section including a low pressure turbine and a high pressure turbine, and a power density of greater than or equal to 4.75 and less than or equal to 5.5 lbf/in.sup.3, wherein the power density is a ratio of a thrust provided by the engine to a volume of the turbine section.

A gas turbine engine includes a propulsor section including a propulsor, a compressor section including a low pressure compressor and a high pressure compressor, a geared architecture, a turbine section including a low pressure turbine and a high pressure turbine, and a power density of greater than or equal to 4.75 and less than or equal to 5.5 lbf/in.sup.3, wherein the power density is a ratio of a thrust provided by the engine to a volume of the turbine section.

A gas turbine engine has a low speed input shaft drives a first plurality of accessories. A high speed input shaft drives a second plurality of accessories. The first plurality of accessories rotating about a first set of rotational axes perpendicular to a first plane. The second plurality of accessories rotating about a second set rotational axes perpendicular to a second plane. The first and second planes extending in opposed directions away from a drive input axis. Compressed air is tapped and passes through a heat exchanger, then to a boost compressor, and then to at least one rotatable components in a main compressor section and a main turbine section. The boost compressor driven on a boost axis, which is non-parallel to the first set of rotational axes and the second set of rotational axes.