Abstract: An axial flow, turbofan gas turbine engine, generally, has a fan section, a compressor section, a combustor section, and a turbine section. An axially extending flow path for working medium gases extends through these sections. The compressor section includes an upstream low pressure compressor and a downstream high pressure compressor. The high pressure compressor is formed by a stator assembly and a rotor assembly. The rotor assembly has a plurality of airfoils or blades which extend radially outward from a rotor disk. During operation, the fan section draws in the working medium gases, as well as, sand. The sand abrades the blades and causes the blades to erode. In an effort to determine the service life remaining in a blade after erosion damage has been done, the present invention relates to a method and a gauge for measuring the service life remaining in a blade.

Abstract: A flow directing apparatus for use in an axial flow turbomachine is disclosed. Techniques for reducing aerodynamic drag along the walls of the flow directing apparatus are developed. In one embodiment, rotor blades have multiplanar platform surfaces which reduce aerodynamic drag pressure losses at the interface between each blade platform and the adjacent structure.