Abstract: A reduction in excitation amplitudes affecting turbine blade durability in a turbine nozzle assembly having a plurality of vanes and turbine blades, includes: identifying a turbine blade design of the turbine nozzle assembly; performing a modal model analysis of at least one of the turbine blades in the turbine blade design; reducing aerodynamic impact by ensuring that each of the turbine blades is free of aero-excitation from an upstream flow at the vanes in an operating speed range; identifying blade natural frequencies with respect to the nozzle vanes; and modifying a trailing edge of at least one of the vanes to reduce the excitation amplitudes.

Abstract: An auxiliary power unit is disclosed that includes a compressor section having a compressor inlet and a compressor exit. A turbine section is arranged downstream from the compressor exit. A diffuser is disposed in fluid communication with and between the compressor section and the turbine section. The diffuser has multiple generally radially extending circumferentially arranged vanes. A shroud housing is secured against the vanes. A damper is arranged between at least one vane and the shroud housing and configured to damp vibration of the at least one vane relative to the shroud housing during operation of the auxiliary power unit.

Abstract: An auxiliary power unit is disclosed that includes a compressor section having a compressor inlet and a compressor exit. A turbine section is arranged downstream from the compressor exit. A diffuser is disposed in fluid communication with and between the compressor section and the turbine section. The diffuser has multiple generally radially extending circumferentially arranged vanes. A shroud housing is secured against the vanes. A damper is arranged between at least one vane and the shroud housing and configured to damp vibration of the at least one vane relative to the shroud housing during operation of the auxiliary power unit.

Abstract: An airfoil for a gas turbine engine component such as a turbine blade is tuned to move its natural frequency outside of a frequency which will be excited during expected speed range of an associated gas turbine engine. The airfoil is tuned about locations of the anti-nodes in an original airfoil design. The tuning affects only the interfered frequency.