According to an aspect, a method includes predicting, by a processor, a projected oil-wetted metal temperature in a lubrication system of a gas turbine engine at shutdown based on one or more thermal models prior to shutdown of the gas turbine engine. The processor determines a coking index based on the projected oil-wetted metal temperature and a coking limit threshold associated with one or more engine components. An oil coking mitigation action is triggered as a shutdown management event of the gas turbine engine based on the coking index.

A method of mitigating thermal rotor bow in a rotor assembly of a turbine engine may include performing a plurality of motoring cycles. The plurality of motoring cycles may include receiving feedback on a temperature within a turbine engine in a post-shutdown state, actuating a starter motor when the temperature is greater than a predetermined threshold, operating the starter motor for a motoring time to exhaust some residual heat from the turbine engine, and shutting down the starter motor after the motoring time.

A method of regulating a temperature associated with a heat exchanger assembly of a turbine engine, the method includes, in a single cycle: measuring the temperature of an air stream at the outlet from a heat exchanger; receiving a setpoint temperature for the air stream at the outlet from the heat exchanger; estimating a theoretical temperature for the air stream at the outlet from the heat exchanger as a function of an estimate of the shutter position of a controlled valve bleeding off a cooling air stream for the heat exchanger; determining a correction current from the difference between the measured temperature and the theoretical temperature; and determining a control current for the shutter from the difference between the measured temperature and the setpoint temperature and the correction current determined during the preceding cycle, the shutter position being determined from the control and correction currents determined during the preceding cycle.

Axially adjacent annular booster bleed aft and forward plenums with annular common wall therebetween extend radially outwardly from transition duct. Variable bleed valve includes bleed valve door in bleed inlet in transition duct, attached to rotatable valve body rotatable about axis of rotation, operable to open and close bleed inlet to aft plenum. Rotatable plenum door clocked or circumferentially spaced apart from variable bleed valve door and attached to rotatable valve body, operable to close and open up and control flow through an inter plenum aperture in common wall. Aft and forward bleed exhaust ducts extend from booster bleed aft and forward plenums to bypass flow path. One or more heat exchanger, such as from thermal management system, may be disposed in the bleed exhaust ducts. Heat exchangers may be used for cooling oil for power gear box and/or engine bearings, air conditioning, or variable frequency generator.

A method of controlling an aircraft gas turbine engine cooling system. The cooling system includes a heat exchanger having a first fluid path through which fan air flows, and a second fluid path through which relatively hot compressor air flows. The cooling system includes a valve configurable between an open position corresponding to a first operating mode, where fan air flows through the first path cooling the compressor air in the second path to a lower temperature, and a closed position corresponding to a second operating mode, where fan air may flow through the first path at a reduced rate, thus the compressor air in the second path could be cooled to a lesser extent. The valve is operated in first mode when the aircraft is in a descent mode, or when turbine entry temperature is above a predetermined amount. Otherwise, the valve is operated in second mode.

A method of modulating cooling flow to an engine component based on a health of the component is provided. The method includes determining a cooling flow requirement of the engine component for each of a plurality of operating conditions and channeling the determined required flow to the engine component during each respective operating condition of the plurality of operating conditions. The method also includes assessing a health of the engine component. The method further includes modifying the determined cooling flow requirement based on the assessed health of the engine component, and supplying the modified cooling flow requirement to the engine component during each subsequent respective operating condition of the plurality of operating conditions.

An engine starting system for a gas turbine engine is provided, the engine starting system comprising: a gas turbine engine including rotational components comprising an engine compressor, an engine turbine, and a rotor shaft operably connecting the engine turbine to the engine compressor, wherein each rotational component is configured to rotate when any one of the rotational components is rotated; an electro-pneumatic starter operably connected to at least one of the rotational components, the electro-pneumatic starter being configured to rotate the rotational components; an electric drive motor operably connected to the electro-pneumatic starter, the electric drive motor being configured to rotate the rotational components through the electro-pneumatic starter; and a motor controller in electronic communication with the electric drive motor, the motor controller being configured to command the electric drive motor to rotate the rotational components at a selected angular velocity for a selected period of time.

The invention aims to shorten the time required for start-up and prevent excessive increases in the heat loads on turbine blades. A humid air turbine includes a compressor; a combustor; a turbine; an exhaust heat recovery unit for recovering the heat of turbine exhaust gas to generate high-temperature moisture; a fuel supply system having a fuel flow rate control valve; an exhaust temperature acquiring unit for acquiring a temperature of the exhaust discharged while the turbine is driven; a combustion gas moisture ratio calculating section for calculating a ratio of moisture contained in combustion gas; an exhaust temperature upper limit calculating section for setting an exhaust temperature upper limit based on the combustion gas moisture ratio and the pressure ratio; an exhaust temperature difference calculating section for calculating the difference between the exhaust temperature upper limit and the exhaust temperature; a fuel flow rate command value calculating section for calculating a fuel flow rate command value using the exhaust temperature difference; and a control command value output section for outputting a command signal to the fuel flow rate control valve based on the command value selected by a fuel flow rate command value selecting section.

A supercharging system for a gas turbine system is provided supercharging system having a fan mechanically coupled to the turbine shaft of the turbine system. A bypass subsystem is provided or optionally conveying a portion of the airstream output to other uses. The supercharging system may also be used in conjunction with a combined cycle power system and a bypass subsystem optionally conveys a portion of the airstream output to a heat recovery steam generator.

A system for protecting the structural integrity of an engine strut may include a first monitor, a second monitor, and a controller communicatively coupled to the first monitor and the second monitor. The first monitor may be mounted proximate an engine strut coupling a turbine engine to an airframe of an aircraft. The second monitor may be mounted proximate the first monitor. The first monitor and the second monitor may each be configured to fail upon reaching a triggering temperature indicative of a burn-through in an engine case during operation of the turbine engine. The controller may be configured to automatically reduce an operating parameter of the turbine engine upon a failure of both the first monitor and the second monitor.