An acoustic device includes: a perforated plate that has a plurality of holes penetrating in a plate thickness direction of the perforated plate and in which a main flow is to flow on a first side of the perforated plate in the plate thickness direction; and a housing that is on a second side of the perforated plate in the plate thickness direction and partitions a space between the housing and the perforated plate, wherein a part of each of the plurality of holes on the first side in the thickness direction is inclined to at least one of the first side and a second side of a flow direction of the main flow.

The present disclosure provides a gas turbine combustor including a combustion structure (10) having a combustor liner (14) and a flow sleeve (12). The combustor liner (14) includes inner and outer surfaces (31, 30) and defines a combustion zone (15). The gas turbine combustor further includes a plurality of hollow airfoil-shaped structures (22) affixed to the combustor liner (14) and extending radially outwardly into an airflow space (18) defined radially between the flow sleeve (12) and the combustor liner (14). Each hollow structure (22) includes at least one metering tube (26) providing acoustic communication between the combustion zone (15) and the hollow structure (22). The metering tubes (26) are detachably coupled to the combustor liner (14) for permitting interchanging of the metering tube (26) with at least one additional metering tube having at least one different dimension to effect a change in an acoustic characteristic of the hollow structure (22).

A grommet for a combustor of a gas turbine engine is disclosed. The grommet includes a lower platform and a raised platform. The lower platform includes a plurality of top slots located in the top surface and a plurality of bottom slots located in the bottom surface. Each top slot and bottom slot may extend radially along the lower platform. The plurality of top slots may be spaced equidistantly from one another along the circumference of the lower platform. The plurality of bottom slots may be spaced equidistantly from one another along the circumference of the lower platform.

A rotating machine component, particularly a gas turbine combustion component, having at least one part built from a porous material with a plurality of pores, wherein at least a subset of the plurality of pores is at least partly filled with a gas with a composition different from air and/or with a powder, wherein the porous material is a laser sintered or laser melted material in which void local regions form the plurality of pores. The component counter-acts vibrations. A rotating machine or gas turbine engine may have such a component.

A sound attenuator includes part of a plate forming a combustion liner and an acoustic cover defining, in conjunction with this part of the plate, a space on the outer circumferential side of the combustion liner. A restrictor that reduces a gas flow path is provided inside the combustion liner. At least one through-hole penetrating from inside the combustion liner to the space is defined in the part of the plate. At least one of the through-holes in the sound attenuator is present within a region spanning from a position of a minimum restrictor diameter of the restrictor to positions, on an upstream side and a downstream side, at a distance equivalent to a minimum restrictor radius.

A combustor and a method involving burner mains structurally configured to damp vibrational modes that can develop under high-frequency combustion dynamics are provided. The combustor may include a carrier (12), and a plurality of mains (16) disposed in the carrier. Some of the mains (labeled with the letter X) include a body having a different structural feature relative to the respective bodies of the remaining mains. The mains with the different structural feature may be selectively grouped in the carrier to form at least one set of such mains effective to damp predefined vibrational modes in the combustor.

An acoustically dampened gas turbine engine (10) having a gas turbine engine combustor (12) with an acoustic damping resonator system (14) is disclosed. The acoustic damping resonator system (14) may be formed from one or more resonators (16) formed from a resonator housing (18) positioned within the gas turbine engine combustor (12) at an outer housing (20) forming a combustor basket (22) and extending circumferentially within the combustor (12). In at least one embodiment, the resonator housing (18) may include resonator chambers (26) that may be welded in place within resonator chamber (26) receivers (24) but easily replaceable without exposing the resonator housing (18) to damage. In another embodiment, an inner surface (32) of the resonator chamber (26) may be offset radially outward from an inner surface (34) of the resonator housing (18), thereby creating a flow-path discontinuity and reducing heating of the resonator chamber (26). The acoustic damping resonator system (14) may mitigate dynamics thereby increasing an engine operating envelope and decreasing emissions.

A method is disclosed for controlling fuel injection in a reheat combustor of a gas turbine combustor assembly including a combustor casing defining a gas flow channel and a plurality of injection nozzles distributed in or around the gas flow channel; the method includes the step of distributing fuel among the injection nozzles according to a non-uniform distribution pattern.

The present disclosure provides a gas turbine combustor liner (34) comprising an outer surface (38) and an inner surface (36), a plurality of film cooling holes (44) through a thickness of the gas turbine combustor liner (34), and a plurality of resonator boxes (32) affixed to the outer surface (38) of the gas turbine combustor liner (34). The film cooling holes (44) extend circumferentially around the gas turbine combustor liner (34) and comprise a first set of holes (56) having a first axial row spacing X and a second set of holes (58) having a second axial row spacing X′. The second set of holes (58) is formed in the gas turbine combustor liner (34) in a downstream direction relative to the first set of holes (56). The second axial row spacing X′ is greater than the first axial row spacing X.

A mixer having a housing, a duct within the housing, a first and a second injector arranged to inject a fluid at a centre zone of the duct, a third and a fourth injector arranged to inject the fluid at a wall zone of the duct. The first/third injectors are at a distance D1=v/2f.sub.1 or odd integer multiples of it from the second/fourth injectors in the absence of an acoustic node between them, or at a distance D1=λ.sub.conv=v/f.sub.1 or full wave length integer multiples of it in the presence of an acoustic node between them. Advantageously f.sub.1 is greater than f.sub.2.