Abstract: An impeller or axial stage compressor disk backface shroud for use with a gas turbine engine is disclosed. The backface shroud includes, but is not limited to, a substantially funnel shaped body having a surface. The substantially funnel shaped body is configured to be statically mounted to the gas turbine engine substantially coaxially with the impeller or axial stage compressor disk. The surface and a backface of the impeller or axial stage compressor disk form a cavity that guides an airflow portion to a turbine when the substantially funnel shaped body is mounted coaxially with the impeller or axial stage compressor disk and axially spaced apart therefrom. The airflow portion has a tangential velocity and a recessed groove in the surface of the backface shroud is oriented generally transversely to the tangential velocity to at least partially interfere with the airflow portion, thus affecting static pressure in the cavity.

Abstract: A gas turbine engine includes a housing with a duct wall that defines a generally annular and axially elongated hot gas flow path for passage of combustion gas. The engine further includes a contoured shroud mounted within the internal engine cavity and defining a hot gas recirculation pocket for receiving hot gas ingested from the hot gas flow path through the annular space and for recirculating the ingested hot gas back through the annular space to the hot gas flow path. The contoured shroud includes a base wall extending radially inwardly from the duct wall, an inboard wall extending from the base wall in an axial direction toward the rotor, and an end wall extending from the inboard wall in a radially outward direction. The end wall terminates in a circumferentially extending free edge disposed in proximity to the annular space. The end wall defines an opening.

Abstract: An impeller or axial stage compressor disk backface shroud for use with a gas turbine engine is disclosed. The backface shroud includes, but is not limited to, a substantially funnel shaped body having a surface. The substantially funnel shaped body is configured to be statically mounted to the gas turbine engine substantially coaxially with the impeller or axial stage compressor disk. The surface and a backface of the impeller or axial stage compressor disk form a cavity that guides an airflow portion to a turbine when the substantially funnel shaped body is mounted coaxially with the impeller or axial stage compressor disk and axially spaced apart therefrom. The airflow portion has a tangential velocity and a recessed groove in the surface of the backface shroud is oriented generally transversely to the tangential velocity to at least partially interfere with the airflow portion, thus affecting static pressure in the cavity.

Abstract: A gas turbine engine includes a housing with a duct wall that defines a generally annular and axially elongated hot gas flow path for passage of combustion gas. The engine further includes a contoured shroud mounted within the internal engine cavity and defining a hot gas recirculation pocket for receiving hot gas ingested from the hot gas flow path through the annular space and for recirculating the ingested hot gas back through the annular space to the hot gas flow path. The contoured shroud includes a base wall extending radially inwardly from the duct wall, an inboard wall extending from the base wall in an axial direction toward the rotor, and an end wall extending from the inboard wall in a radially outward direction. The end wall terminates in a circumferentially extending free edge disposed in proximity to the annular space. The end wall defines an opening.