Systems and methods relating to use of external air for inventory control of a closed thermodynamic cycle system or energy storage system, such as a reversible Brayton cycle system, are disclosed. A method may involve, in a closed cycle system operating in a power generation mode, circulating a working fluid may through a closed cycle fluid path. The closed cycle fluid path may include a high pressure leg and a low pressure leg. The method may further involve in response to a demand for increased power generation, compressing and dehumidifying environmental air. And the method may involve injecting the compressed and dehumidified environmental air into the low pressure leg.

Systems and methods relating to use of external air for inventory control of a closed thermodynamic cycle system or energy storage system, such as a reversible Brayton cycle system, are disclosed. A method may involve, in a closed cycle system operating in a power generation mode, circulating a working fluid may through a closed cycle fluid path. The closed cycle fluid path may include a high pressure leg and a low pressure leg. The method may further involve in response to a demand for increased power generation, compressing and dehumidifying environmental air. And the method may involve injecting the compressed and dehumidified environmental air into the low pressure leg.

The invention relates to a turbine engine combustion module (10), in particular for an aircraft turbine engine, designed to carry out constant-volume combustion, comprising: at least two combustion chambers (12A, 12B) arranged about an axis, each chamber (12A, 12B, 12C) comprising a compressed gas intake port (16) and a burnt gas exhaust port (18); and an ignition means that triggers combustion in the combustion chambers (12A, 12B, 12C). The module (10) comprises at least one duct (80) which establishes a communication between a first combustion chamber (12A) and at least one second combustion chamber (12B) in order to inject burnt gases from the first combustion chamber (12A) into the second combustion chamber (12B) so as to trigger combustion in the second combustion chamber (12B).

A system for operating a gas turbine engine to mitigate the risk of ice formation within the engine, the system including a controller arranged to control at least one operational parameter of the engine such that the engine operates in a safe zone; and, a processor configured to function as a determining module to make a comparison between values and determine whether the engine is operating within a safe zone based on at least a core pressure parameter relating to the pressure within the engine and a core temperature parameter relating to the temperature within the engine, wherein the safe zone is defined by the product (multiplied) of the core pressure parameter and core temperature parameter being above a safe threshold.

A system for operating a gas turbine engine to mitigate the risk of ice formation within the engine, the system including a controller arranged to control at least one operational parameter of the engine such that the engine operates in a safe zone; and, a processor configured to function as a determining module to make a comparison between values and determine whether the engine is operating within a safe zone based on at least a core pressure parameter relating to the pressure within the engine and a core temperature parameter relating to the temperature within the engine, wherein the safe zone is defined by the product (multiplied) of the core pressure parameter and core temperature parameter being above a safe threshold.

Control systems and methods suitable for combination with power production systems and methods are provided herein. The control systems and methods may be used with, for example, closed power cycles as well as semi-closed power cycles. The combined control systems and methods and power production systems and methods can provide dynamic control of the power production systems and methods that can be carried out automatically based upon inputs received by controllers and outputs from the controllers to one or more components of the power production systems.

Control systems and methods suitable for combination with power production systems and methods are provided herein. The control systems and methods may be used with, for example, closed power cycles as well as semi-closed power cycles. The combined control systems and methods and power production systems and methods can provide dynamic control of the power production systems and methods that can be carried out automatically based upon inputs received by controllers and outputs from the controllers to one or more components of the power production systems.

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.

Control systems and methods suitable for combination with power production systems and methods are provided herein. The control systems and methods may be used with, for example, closed power cycles as well as semi-closed power cycles. The combined control systems and methods and power production systems and methods can provide dynamic control of the power production systems and methods that can be carried out automatically based upon inputs received by controllers and outputs from the controllers to one or more components of the power production systems.