A gas turbine engine for an aircraft and a method of operating a gas turbine engine on an aircraft. Embodiments disclosed include a gas turbine engine for an aircraft including: an engine core has a turbine, a compressor, and a core shaft; a fan located upstream of the engine core, the fan has a plurality of fan blades; a nacelle surrounding the engine core and defining a bypass duct and bypass exhaust nozzle; and a gearbox that receives an input from the core shaft and outputs drive to the fan wherein the gas turbine engine is configured such that a jet velocity ratio of a first jet velocity exiting from the bypass exhaust nozzle to a second jet velocity exiting from an exhaust nozzle of the engine core at idle conditions is greater by a factor of 2 or more than the jet velocity ratio at maximum take-off conditions.

A gas turbine engine for an aircraft and a method of operating a gas turbine engine on an aircraft. Embodiments disclosed include a gas turbine engine for an aircraft including: an engine core has a turbine, a compressor, and a core shaft; a fan located upstream of the engine core, the fan has a plurality of fan blades; a nacelle surrounding the engine core and defining a bypass duct and bypass exhaust nozzle; and a gearbox that receives an input from the core shaft and outputs drive to the fan wherein the gas turbine engine is configured such that a jet velocity ratio of a first jet velocity exiting from the bypass exhaust nozzle to a second jet velocity exiting from an exhaust nozzle of the engine core at idle conditions is greater by a factor of 2 or more than the jet velocity ratio at maximum take-off conditions.

A gas turbine engine comprising: a combustor configured to initiate combustion; and a turbine comprising a stator vane ring defining a plurality of passageways between adjacent vanes; wherein at least one of the passageways is provided with a restrictor which defines a temporary gas washed surface for the stator vane ring and is configured to be ablated upon initiation of combustion to reveal an operational gas washed surface of the stator vane ring. A method of starting a gas turbine engine is also described.

A gas turbine engine comprising: a combustor configured to initiate combustion; and a turbine comprising a stator vane ring defining a plurality of passageways between adjacent vanes; wherein at least one of the passageways is provided with a restrictor which defines a temporary gas washed surface for the stator vane ring and is configured to be ablated upon initiation of combustion to reveal an operational gas washed surface of the stator vane ring. A method of starting a gas turbine engine is also described.

A method for controlling a gas turbine engine includes receiving, by a signal processor from a sensor, an operating condition of the gas turbine engine and determining, by the signal processor, whether the operating condition is within an acceptable threshold. In response to the operating condition being outside the acceptable threshold, the method includes restricting, by the signal processor, a subsequent engine restart of the gas turbine engine. Restricting the subsequent engine restart of the gas turbine engine may comprise preventing the subsequent restart. In various embodiments, restricting the subsequent engine restart of the gas turbine engine comprises limiting a subsequent operating state of the gas turbine engine after the subsequent restart.

A method for controlling a gas turbine engine includes receiving, by a signal processor from a sensor, an operating condition of the gas turbine engine and determining, by the signal processor, whether the operating condition is within an acceptable threshold. In response to the operating condition being outside the acceptable threshold, the method includes restricting, by the signal processor, a subsequent engine restart of the gas turbine engine. Restricting the subsequent engine restart of the gas turbine engine may comprise preventing the subsequent restart. In various embodiments, restricting the subsequent engine restart of the gas turbine engine comprises limiting a subsequent operating state of the gas turbine engine after the subsequent restart.

A power plant with a water-steam-cycle includes a steam generator with a plurality of heating surfaces that carry a fluid and transfer heat to the fluid. The plurality of heating surfaces has an economizer for preheating the fluid and a fluidly connected evaporator for producing steam. A steam turbine receives the steam produced in the steam generator to generate power output. A condenser condenses steam from the steam turbine. The condenser has a hotwell as collection container for condensed steam or water. A polishing plant is arranged fluidly between the hotwell of the condenser and the economizer. A drain line interconnects an outlet of the economizer and the hotwell of the condenser. A fluid line interconnects the outlet of the economizer and the evaporator. The fluid line includes a syphon to hold back water in the economizer.

A power plant with a water-steam-cycle includes a steam generator with a plurality of heating surfaces that carry a fluid and transfer heat to the fluid. The plurality of heating surfaces has an economizer for preheating the fluid and a fluidly connected evaporator for producing steam. A steam turbine receives the steam produced in the steam generator to generate power output. A condenser condenses steam from the steam turbine. The condenser has a hotwell as collection container for condensed steam or water. A polishing plant is arranged fluidly between the hotwell of the condenser and the economizer. A drain line interconnects an outlet of the economizer and the hotwell of the condenser. A fluid line interconnects the outlet of the economizer and the evaporator. The fluid line includes a syphon to hold back water in the economizer.

A system may comprise a sensor configured to measure a characteristic of an engine component. A valve assembly may have an airflow outlet in fluid communication with the engine component. The valve assembly may include a first valve. A first valve control device may be coupled to the first valve and configured to control the first valve based on a measurement by the sensor. A second valve may be in fluidic series with the first valve. A second valve control device may be coupled to the second valve and configured to control the second valve based on the measurement by the sensor.

A system may comprise a sensor configured to measure a characteristic of an engine component. A valve assembly may have an airflow outlet in fluid communication with the engine component. The valve assembly may include a first valve. A first valve control device may be coupled to the first valve and configured to control the first valve based on a measurement by the sensor. A second valve may be in fluidic series with the first valve. A second valve control device may be coupled to the second valve and configured to control the second valve based on the measurement by the sensor.