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: A cooling system for the rear bearing capsule of a turbine in a gas turbine engine supported by an exhaust cone attached to multiple exit guide vanes that extend radially from the exhaust cone to an exhaust housing, comprises: an inlet air flow path through each guide vane between a source of cool ambient air and the rear bearing capsule; and at least one discharge air flow path that receives air from the inlet air flow path through each guide vane and passes the air through the exhaust cone from the rear bearing capsule to a high velocity gas flow path in the exhaust housing.