Abstract: A method of modifying a turbine nozzle area comprises depositing a thermal barrier coating (TBC) on the nozzle endwalls to provide a minimum nozzle area, evaluating an airflow through the nozzle, and machining the TBC to increase the nozzle area. Adjacent segment area variation may be minimized, improving engine reliability by reducing the aerodynamic excitation to the down stream blade.

Abstract: A cooled shroud assembly includes an angled slot and a plurality of dilution jet openings. The shroud forward cavity is modified such that at least one recirculation zone is produced. The angled slot forces an axial change in momentum of the hot gas flow and increases radial and axial pressure variation attenuation. The cooled shroud assembly isolates the shroud structure and seals from the hot flow path and a cooling flow from the dilution jet openings dilutes the hot gas flow. A series of recirculation zones shields the shroud carrier and high pressure seals from the hot gas flow.