Compressor diffuser with diffuser pipes having aero-dampers

A gas turbine engine comprising a centrifugal compressor rotatable about a central axis and a combustor downstream of the centrifugal compressor relative to a flow of compressed air exiting the centrifugal compressor, the centrifugal compressor including an impeller and a diffuser pipe assembly downstream of the impeller, the diffuser pipes having diffuser conduits for circulating the flow of compressed air, the diffuser pipe assembly configured for redirecting the flow of compressed air from a radial direction to an axial direction relative to the central axis, the diffuser pipe assembly including diffuser pipes circumferentially distributed around the central axis, the diffuser pipes defining diffuser conduits fluidly connected to the impeller and to the combustor, and a first subset of the diffuser pipes having aero-dampers within the diffuser conduits such that the diffuser pipes of the first subset have a natural vibration frequency different than a natural vibration frequency of at least a second subset of the diffuser pipes.

A method of operating a centrifugal compressor of a gas turbine engine, the centrifugal compressor having an impeller and a diffuser pipe assembly downstream thereof, the method comprising:

• separating a flow of air exiting the impeller in sub-flows of air, and feeding the sub-flows of air to diffuser pipes of the diffuser pipe assembly and directing the fed sub-flows through the diffuser pipes toward the combustor;
• and
• limiting a transfer of vibrations from at least one of the diffuser pipes to adjacent diffuser pipes by varying a natural vibration frequency of at least one of the diffuser pipes relative to the adjacent diffuser pipes by aerodynamically damping the at least one of the diffuser pipes to generate a natural vibration frequency offset between the at least one of the diffuser pipes and the adjacent diffuser pipes.