Impeller backface shroud for use with a gas turbine engine

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.