A method for operating start-up of a compressor train is disclosed. The train includes a driver machine and at least a centrifugal compressor drivingly coupled to the driver machine. The centrifugal compressor in turn includes a plurality of compressor stages and at least a first set of variable inlet guide vanes at an inlet of one of the compressor stages. The method includes at least partly closing the first set of variable inlet guide vanes; when the first set of variable inlet guide vanes is at least partly closed, starting rotation of the centrifugal compressor and accelerating the centrifugal compressor up to a minimum operating speed; opening the at least one set of variable inlet guide vanes to increase the gas flow through the centrifugal compressor once the minimum operating speed has been achieved.

A method for operating start-up of a compressor train is disclosed. The train includes a driver machine and at least a centrifugal compressor drivingly coupled to the driver machine. The centrifugal compressor in turn includes a plurality of compressor stages and at least a first set of variable inlet guide vanes at an inlet of one of the compressor stages. The method includes at least partly closing the first set of variable inlet guide vanes; when the first set of variable inlet guide vanes is at least partly closed, starting rotation of the centrifugal compressor and accelerating the centrifugal compressor up to a minimum operating speed; opening the at least one set of variable inlet guide vanes to increase the gas flow through the centrifugal compressor once the minimum operating speed has been achieved.

Methods and systems for determining an engine temperature for a gas turbine engine are provided. An estimated combustor temperature is determined based on at least one operating condition of the gas turbine engine and an estimated vane mass flow. A corrected vane mass flow is determined based on the estimated combustor temperature, the estimated vane mass flow, and a combustor pressure. The corrected vane mass flow is compared to a reference vane mass flow to obtain the mass flow correction factor. When a condition associated with the mass flow correction factor is not satisfied, the estimated combustor temperature is adjusted based on the mass flow correction factor to produce an adjusted combustor temperature; and the mass flow correction factor is updated based on the adjusted combustor temperature. When the condition associated with the mass flow correction factor is satisfied, the estimated combustor temperature is assigned as the engine temperature.

The turboshaft engine for a rotorcraft includes a low pressure spool having a low pressure compressor and a low pressure turbine section, and a high pressure spool having a high pressure compressor and a high pressure turbine section. The spools are independently rotatable relative to one another. The low pressure compressor section includes a mixed flow rotor. A set of variable guide vanes (VGVs) are discposed upstream of each of the low pressure and high pressure compressors, the VGVs being configured to be independently operable relative to one another.

There are provided a throttle mechanism and the like that are capable of easily changing a cross-sectional area of a flow path according to an operating state. The throttle mechanism in an embodiment is a throttle mechanism that controls a flow rate of a fluid flowing through a flow path, and is configured to make a cross-sectional area of the flow path change autonomously according to temperature.

There are provided a throttle mechanism and the like that are capable of easily changing a cross-sectional area of a flow path according to an operating state. The throttle mechanism in an embodiment is a throttle mechanism that controls a flow rate of a fluid flowing through a flow path, and is configured to make a cross-sectional area of the flow path change autonomously according to temperature.

Vehicles, such as aircraft, may include turbine-based combined cycle power plants (TBCC) for power to achieve high-mach speeds. An anti-unstart configuration provides control for transitioning between the amount of air directed to either engine during operation of gas turbine engine and scramjet engines, to avoid unstart during operation above sonic speeds.

A system for modulating airflow into a bore defined by a rotor of a gas turbine engine defining an axial direction, a circumferential direction, and a radial direction is provided. The system includes a movable member positioned forward of a first stage of rotor blades of the rotor. The movable member is movable between at least a first position and a second position to modulate airflow into the bore via a plurality of opening in fluid communication with the bore.

A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a low speed spool and a high speed spool; a rotor assembly coupled to the low speed spool; an electric machine rotatable with the low speed spool for extracting power from the low speed spool, for adding power to the low speed spool, or both; and an inter-spool clutch positioned between the low speed spool and the high speed spool for selectively coupling the low speed spool to the high speed spool.

A control device includes a load fuel quantity calculation unit, an allowable fuel quantity calculation unit, a flow rate low value selection unit, a basic drive quantity calculation unit, a fuel deviation calculation unit, and a correction unit. The load fuel quantity calculation unit determines a load fuel quantity based on a required output. The allowable fuel quantity calculation unit determines an allowable fuel quantity to protect a gas turbine. The flow rate low value selection unit selects a minimum fuel quantity from among the determined fuel quantities. The basic drive quantity calculation unit determines a basic drive quantity of an air intake quantity regulator. The fuel deviation calculation unit determines a fuel deviation between the allowable fuel quantity and the minimum fuel quantity. The correction value calculation unit determines a correction value corresponding to the fuel deviation which is then used to correct the basic drive quantity.