A system has: a combustor; a plenum surrounding the combustor; a transfer tube having an inlet fluidly connected to the plenum and at least two outlets, a first flow passageway defined between the inlet and a first outlet, a second flow passageway defined between the inlet and a second outlet, the second flow passageway connected to a discharge region outside of the plenum; a flow valve disposed within the second flow passageway and operable between an open position and a closed position, in the open position the flow valve fluidly connects the plenum with the discharge region, in the closed position the flow valve blocking fluid communication between the plenum and the discharge region; and a controller communicatively coupled to the flow valve to control operation thereof by: causing the flow valve to open for a time period; and subsequent to the time period, causing the flow valve to close.

A gas turbine engine includes combustion apparatus defining a volume, a compressor, a cooling air supply feed from the compressor, and a Helmholtz resonator. The Helmholtz resonator has a neck and a chamber having an attenuation volume and which is in fluid communication with the attenuation volume, the cooling air supply feed is connected to the Helmholtz resonator and includes a valve arrangement. In a first engine operating condition, the valve arrangement is closed and the Helmholtz resonator attenuates acoustic frequencies in a first range and, in a second engine operating condition, the valve arrangement is open whereby cooling air purges the attenuation volume and the Helmholtz resonator attenuates acoustic frequencies in a second range.

A structure for damping at a fluid manifold assembly for an engine is generally provided. The fluid manifold assembly includes a first walled conduit defining a first fluid passage therewithin. A flow of fluid defining a first frequency is permitted through the first fluid passage. A second walled conduit includes a pair of first portions each coupled to the first walled conduit. A second portion is coupled to the pair of first portions. A second fluid passage is defined through the first portion and the second portion in fluid communication with the first fluid passage. The flow of fluid is permitted through the second fluid passage at a second frequency approximately 180 degrees out of phase from the first frequency.

A fuel control device includes a combustion temperature estimation value calculation unit that calculates a temperature estimation value when a mixture of fuel and inflow air is burned using an atmospheric condition, an opening degree command value of a valve that controls the amount of air that is mixed with the fuel and burned, and an output prediction value calculated on the basis of a fuel control signal command value used for calculation of a total fuel flow rate flowing through a plurality of fuel supply systems, a fuel distribution command value calculation unit that calculates a fuel distribution command value indicating a distribution of fuel output from the fuel supply systems based on the temperature estimation value, and outputs the fuel distribution command value, and a valve opening degree calculation unit that calculates each valve opening degree of a fuel flow rate control valve of the fuel supply systems.

A structure for damping at a fluid manifold assembly for an engine is generally provided. The fluid manifold assembly includes a first walled conduit defining a first fluid passage therewithin. A flow of fluid defining a first frequency is permitted through the first fluid passage. A second walled conduit includes a pair of first portions each coupled to the first walled conduit. A second portion is coupled to the pair of first portions. A second fluid passage is defined through the first portion and the second portion in fluid communication with the first fluid passage. The flow of fluid is permitted through the second fluid passage at a second frequency approximately 180 degrees out of phase from the first frequency.

[Object] To observe the sign or occurrence of an unstable operation of a turbo-machine. [Solving Means] An observation apparatus 1 includes: a detection unit 10 including one or two or more sensors 11, 12 that are disposed in a turbo-machine 2, are highly time responsive, and observe unsteady fluctuations of the turbo-machine 2; a computation unit 20 that output signals from the one or two or more sensors 11, 12 every moment, stores time series data for a predetermined period, and calculates in real time a parameter for detecting an unstable operation of the turbo-machine; and a determination unit 30 that compares the parameter for detecting the unstable operation with a predetermined threshold and outputs in real time a determination result of a sign or occurrence of the unstable operation.

A system includes a gas turbine engine having a first combustor and a second combustor. The first combustor includes a first fuel conduit having a first plurality of injectors. The first plurality of injectors are disposed in a first configuration within the first combustor along a first fuel path, and the first plurality of injectors are configured to route a fuel to a first combustion chamber. The system further includes a second combustor having a second fuel conduit having a second plurality of injectors. The second plurality of injectors are disposed in a second configuration within the second combustor along a second fuel path, and the second plurality of injectors are configured to route the fuel to a second combustion chamber. The second configuration has at least one difference relative to the first configuration.

A propulsion system including: a fuel cell assembly comprising a fuel cell, the fuel cell defining an outlet positioned to remove output products from the fuel cell and a fuel cell assembly operating condition; a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order, the combustion section configured to receive a flow of aviation fuel from the aircraft fuel supply and further configured to receive the output products from the fuel cell; and a controller comprising memory and one or more processors, the memory storing instructions that when executed by the one or more processors cause the propulsion system to perform operations including: delivering the output products from the fuel cell to the combustion section to mitigate combustion dynamics within the combustion section.

A combustor includes an annular dome and a plurality of dampers integral with the annular dome. Each of the plurality of dampers includes an adjustable damper cover and a damper portion defining a cavity having a volume. The damper cover is mounted to the damper portion integrated with the annular dome and is movable to adjust the volume of the cavity to adjust a frequency of each of the plurality of dampers to reduce an acoustic amplitude of the combustor.

A method of operating a control unit for controlling at least two different input fuel flows to a combustion device, e.g. a gas turbine includes the step of determining on the basis of at least one operating parameter whether the combustion device is in a predefined operating stage. In response hereto, generating a control signal configured for setting a ratio of at least two different input fuel flows to a predetermined value (psc1, psc3) for a predetermined time (dt) in case the combustion device is in the predefined operating stage.