Impeller backface shroud for use with a gas turbine engine

A gas turbine engine comprising:

• a shaft;
• an impeller or axial stage compressor disk affixed to the shaft;
• a turbine affixed to the shaft at a location aft of the impeller;
• and
• an impeller or axial stage compressor disk backface shroud comprising:
• a substantially funnel shaped body having a surface, the substantially funnel shaped body being statically mounted to the gas turbine engine in a position that is substantially coaxial with the impeller or axial stage compressor disk and axially spaced apart therefrom in an aft direction such that the surface and a backface of the impeller or axial stage compressor disk form a cavity, the cavity being configured to guide an airflow portion from the impeller or axial stage compressor disk to the turbine, the airflow portion having a tangential velocity;
• and
• a recessed groove defined in the surface with first and second closed longitudinal ends, the recessed groove oriented generally transversely to the tangential velocity of the airflow portion and configured to at least partially interfere with the airflow portion, whereby a static pressure in the cavity is increased.

An impeller or axial stage compressor disk backface shroud for use with a gas turbine engine having an impeller or axial stage compressor disk, the impeller or axial stage compressor disk backface shroud comprising:

• a substantially funnel shaped body having a surface, the substantially funnel shaped body configured to be statically mounted to the gas turbine engine in a position that is substantially coaxial with the impeller or axial stage compressor disk, the surface and a backface of the impeller or axial stage compressor disk forming a cavity configured to guide an airflow portion from the impeller to a turbine when the substantially funnel shaped body is mounted to the gas turbine engine coaxially with the impeller or axial stage compressor disk and axially spaced apart therefrom in an aft direction;
• and
• a recessed groove defined in the surface,
• wherein the airflow portion has a tangential velocity and wherein the recessed groove is oriented generally transversely to the tangential velocity of the airflow portion and configured to at least partially interfere with the airflow portion, whereby a static pressure in the cavity is affected,
• wherein the recessed groove includes first and second closed radial ends.