Systems and methods to pump fracturing fluid into a wellhead may include a gas turbine engine including a compressor turbine shaft connected to a compressor, and a power turbine output shaft connected to a power turbine. The compressor turbine shaft and the power turbine output shaft may be rotatable at different rotational speeds. The systems may also include a transmission including a transmission input shaft connected to the power turbine output shaft and a transmission output shaft connected to a hydraulic fracturing pump. The systems may also include a fracturing unit controller configured to control one or more of the rotational speeds of the compressor turbine shaft, the power turbine output shaft, or the transmission output shaft based at least in part on target signals and fluid flow signals indicative of one or more of pressure or flow rate associated with fracturing fluid pumped into the wellhead.

A gas turbine propulsion system includes a shroud that defines a fluid flow path. A gas turbine engine in the fluid flow path includes a compressor, a combustor downstream from the compressor, and a turbine downstream from the combustor. An electric generator in the fluid flow path includes a rotor coaxially aligned with the turbine. A propulsor is upstream from the gas turbine engine, and an electric motor is operably coupled to the propulsor to rotate the propulsor. The propulsor is rotationally isolated from the gas turbine engine so that the propulsor rotates independently from operation of the gas turbine engine.

A method of manufacturing a motoring system for a gas turbine engine including the steps of: forming a mechanical shaft fuse, the mechanical shaft fuse including a plurality of through holes; forming an outer housing; installing a reduction gear train into the outer housing, the reduction gear train having an input and an output; operably connecting an electric motor to the input; operably connecting a clutch to the output using the mechanical shaft fuse, the clutch in operation engages and disengages the reduction gear train; operably connecting a starter to the clutch, the starter having an output shaft; and operably connecting an accessory gearbox to the output shaft of the starter. The mechanical shaft fuse in operation shears when torque on the mechanical is greater than or equal to a selected value.

A method of manufacturing a motoring system for a gas turbine engine including the steps of: forming a mechanical shaft fuse, the mechanical shaft fuse including a plurality of through holes; forming an outer housing; installing a reduction gear train into the outer housing, the reduction gear train having an input and an output; operably connecting an electric motor to the input; operably connecting a clutch to the output using the mechanical shaft fuse, the clutch in operation engages and disengages the reduction gear train; operably connecting a starter to the clutch, the starter having an output shaft; and operably connecting an accessory gearbox to the output shaft of the starter. The mechanical shaft fuse in operation shears when torque on the mechanical is greater than or equal to a selected value.

A gas turbine engine having: an engine core having, in serial flow communication, a low-pressure compressor, a high-pressure compressor, a high-pressure turbine drivingly connected to the high-pressure compressor, and a low-pressure turbine drivingly connected to an output shaft; and a clutch having a disengaged configuration in which the low-pressure turbine is drivingly disconnected from the low-pressure compressor such that, in the disengaged configuration, the clutch disengages the low-pressure turbine from the low-pressure compressor, and an engaged configuration in which the low-pressure turbine is drivingly connected to the low-pressure compressor, the low-pressure turbine drivingly connected to the output shaft in both of the engaged and disengaged configurations of the clutch.

A turbine engine with a turbine core that includes a compressor section having a compressor coupled to a high speed shaft, a combustion section, a turbine section having a high pressure turbine coupled to the high speed shaft and a low pressure turbine coupled to a low speed shaft, and a nozzle section. The turbine engine also includes an electric machine that can operate in a first starting mode and a second generating mode.

An operating method is provided during which a plurality of start parameters for a gas turbine engine are determined. A first of the start parameters is indicative of a temperature of air at an inlet into the gas turbine engine. A second of the start parameters is indicative of a pressure of the air at the inlet. Rotation of a rotating assembly of the gas turbine engine is driven. The rotating assembly includes a compressor rotor and a turbine rotor. The compressor rotor is within a compressor section of the gas turbine engine. The turbine rotor is within a turbine section of the gas turbine engine. Fuel is directed into a combustion chamber of the gas turbine engine based on the start parameters and a speed parameter. The speed parameter is indicative of a speed of the rotation of the rotating assembly. A mixture of the fuel and compressed air within the combustion chamber is ignited to start the gas turbine engine.

Embodiments of systems and methods for operating a gas turbine engine defining a bowed rotor condition are generally provided. The systems and methods include rotating a rotor assembly defining a bowed rotor condition from approximately zero revolutions per minute (RPM) to within a bowed rotor mitigation speed range, in which the bowed rotor mitigation speed range is defined by a lower speed limit greater than zero RPM and an upper speed limit less than or equal to an idle speed condition of the gas turbine engine; applying a load at the rotor assembly via an energy storage device; adjusting the load to limit rotational speed or acceleration of the rotor assembly to within the bowed rotor mitigation speed range for a period of time; and removing the load to enable rotation of the rotor assembly to the idle speed condition following the period of time.

A gas turbine includes a compressor, a turbine, and a combustor disposed downstream from the compressor and upstream from the turbine. The combustor includes an end cover. The combustor also includes a flange. The flange includes an internal fluid passage defined within the flange and the flange is coupled to an internal face of the end cover. A fuel port is integrally joined with the flange. The fuel port extends through the end cover between the flange and an inlet positioned outside of the end cover. The inlet of the fuel port is in fluid communication with the internal fluid passage of the flange.

A gas turbine includes a compressor, a turbine, and a combustor disposed downstream from the compressor and upstream from the turbine. The combustor includes an end cover. The combustor also includes a flange. The flange includes an internal fluid passage defined within the flange and the flange is coupled to an internal face of the end cover. A fuel port is integrally joined with the flange. The fuel port extends through the end cover between the flange and an inlet positioned outside of the end cover. The inlet of the fuel port is in fluid communication with the internal fluid passage of the flange.