Abstract: A gas turbine includes one or more combustors, and each combustor may include one or more fuel nozzles for mixing fuel with a compressed working fluid prior to combustion. The gas turbine further includes various structures for reducing the modal coupling of the combustion dynamics by producing a different convective time, fuel flow, and/or compressed working fluid flow through at least one fuel nozzle.

Abstract: A system and method for operating a gas turbine include a controller that determines, for at least one combustion instability, a frequency; a quantification of the frequency or a quantification of the frequency through time; and, optionally, a phase and/or an amplitude. The logic also causes the controller to compare the frequency, the quantification of the frequency or the quantification of the frequency through time, the phase, and/or the amplitude of the at least one combustion instability to an associated predetermined limit. When the frequency is actionable relative to its predetermined limit and one of the quantification of the frequency or the quantification of the frequency through time is actionable relative to its respective predetermined limit, at least one parameter of the gas turbine is adjusted. The quantification of the frequency is one of the standard deviation, the coefficient of variation, the index of dispersion, and the variance.

Abstract: Certain embodiments herein relate to systems and methods for managing a combustor of a gas turbine engine. In one embodiment, a system can include at least one memory configured to store computer-executable instructions and at least one controller configured to access the at least one memory and execute the computer-executable instructions. The instructions may be configured to monitor the dynamic and static pressures of the combustor by a single sensor. The instructions may be further configured to generate a signal based at least in part on the dynamic and static pressures. Furthermore, the instructions may be configured to facilitate in the execution of at least combustor control event based at least in part on the signal.

Abstract: A system and method for reducing combustion dynamics includes first and second combustors, and each combustor includes a fuel nozzle and a combustion chamber downstream from the fuel nozzle. Each fuel nozzle includes an axially extending center body, a shroud that circumferentially surrounds at least a portion of the axially extending center body, a plurality of vanes that extend radially between the center body and the shroud, a first fuel port through at least one of the plurality of vanes at a first axial distance from the combustion chamber, a second fuel port through the center body at a second axial distance from the combustion chamber, and the plurality of vanes are at a third axial distance from the combustion chamber. The system further includes structure for producing a combustion instability frequency in the first combustor that is different from the combustion instability frequency in the second combustor.

Abstract: A system and method for reducing combustion dynamics includes first and second combustors arranged about an axis, and each combustor includes a cap assembly that extends radially across at least a portion of the combustor and a combustion chamber downstream from the cap assembly. Each cap assembly includes a plurality of tubes that extend axially through the cap assembly to provide fluid communication through the cap assembly to the combustion chamber and a fuel injector that extends through each tube to provide fluid communication into each tube. Each cap assembly has an axial length, and the axial length of the cap assembly in the first combustor is different than the axial length of the cap assembly in the second combustor.

Abstract: A system and method for reducing combustion dynamics includes first and second combustors arranged about an axis, and each combustor includes a plurality of tubes that extend axially through at least a portion of the combustor and a combustion chamber downstream from the plurality of tubes. A fuel injector extends through each tube to provide fluid communication into each tube at a fourth axial distance from the combustion chamber. The fourth axial distance in the first combustor is different than the fourth axial distance in the second combustor.

Abstract: A turbomachine combustor assembly includes a combustor body, and a combustor liner arranged within the combustor body and defining a combustion chamber. The combustor liner includes a venturi portion arranged within the combustion chamber. A fluid passage is defined between the combustor body and the combustor liner, and at least one turbulator is arranged in the fluid passage. The at least one turbulator is configured and disposed to create vortices in the fluid passage. A vortex modification system is arranged at the fluid passage and is configured and disposed to disrupt the vortices in the fluid passage.

Abstract: A system and method for reducing combustion dynamics includes first and second combustors arranged about an axis, and each combustor includes a plurality of tubes that extend axially through at least a portion of the combustor and a combustion chamber downstream from the plurality of tubes. A fuel injector extends through each tube to provide fluid communication into each tube at a fourth axial distance from the combustion chamber. The fourth axial distance in the first combustor is different than the fourth axial distance in the second combustor.

Abstract: A fuel nozzle includes a center body that extends axially along an axial centerline for a length. A shroud circumferentially surrounds the center body for at least a portion of the length of the center body. A plurality of helical passages circumferentially surround the center body along at least a portion of the length of the center body, and a fuel port in each helical passage has a different convective time.

Abstract: The present application provides a fuel delivery system for a combustor with reduced coherence and/or reduced combustion dynamics. The combustor can assembly may include a first manifold for delivering a first flow of fuel to a first set of fuel injectors and a second manifold for delivering a second flow of fuel to a second set of fuel injectors. The first flow of fuel may have a first temperature and the second flow of fuel may have a second temperature. The first temperature may be higher than the second temperature.

Abstract: Systems and methods for frequency separation in a gas turbine engine are provided herein. The systems and methods for frequency separation in a gas turbine engine may include determining a hot gas path natural frequency, determining a combustion dynamic frequency, and modifying a compressor discharge temperature to separate the combustion dynamic frequency from the hot gas path natural frequency.

Abstract: A system for reducing modal coupling of combustion dynamics includes a plurality of combustors, and at least one fuel injector in each of the plurality of combustors. The system also includes structure for dithering a combustion instability frequency in at least one combustor in the plurality of combustors. A method for reducing modal coupling of combustion dynamics includes flowing a compressed working fluid at a temperature to a plurality of combustors and flowing a fuel to at least one fuel injector in each of the plurality of combustors. The method further includes dithering at least one of the temperature of the compressed working fluid flowing to the plurality of combustors or the fuel flow to the at least one fuel injector in at least one combustor in the plurality of combustors.

Abstract: A system and method for reducing combustion dynamics includes first and second combustors, and each combustor includes a fuel nozzle and a combustion chamber downstream from the fuel nozzle. Each fuel nozzle includes an axially extending center body, a shroud that circumferentially surrounds at least a portion of the axially extending center body, a plurality of vanes that extend radially between the center body and the shroud, a first fuel port through at least one of the plurality of vanes at a first axial distance from the combustion chamber, the plurality of vanes being located at a second axial distance from the combustion chamber. A second fuel port is provided through the center body at a third axial distance from the combustion chamber. The system further includes structure for producing a combustion instability frequency in the first combustor that is different from the combustion instability frequency in the second combustor.

Abstract: A combustor having a combustion chamber is provided with an external flow sleeve and a combustor liner surrounding the combustion chamber. A plurality of flow channels are provided on the combustor liner and a plurality of nozzles are disposed at predetermined locations on the flow channels. The locations of the nozzles are selected to provide different mixing times for fuel injected through the nozzles.

Abstract: A system and method for reducing combustion dynamics includes first and second combustors arranged about an axis, and each combustor includes a cap assembly that extends radially across at least a portion of the combustor and a combustion chamber downstream from the cap assembly. Each cap assembly includes a plurality of tubes that extend axially through the cap assembly to provide fluid communication through the cap assembly to the combustion chamber and a fuel injector that extends through each tube to provide fluid communication into each tube. Each cap assembly has an axial length, and the axial length of the cap assembly in the first combustor is different than the axial length of the cap assembly in the second combustor.

Abstract: A turbomachine combustor assembly includes a combustor body, and a combustor liner arranged within the combustor body and defining a combustion chamber. The combustor liner includes a venturi portion arranged within the combustion chamber. A fluid passage is defined between the combustor body and the combustor liner, and at least one turbulator is arranged in the fluid passage. The at least one turbulator is configured and disposed to create vortices in the fluid passage. A vortex modification system is arranged at the fluid passage and is configured and disposed to disrupt the vortices in the fluid passage.