Patent ID: 9581440
Date: 2017-02-28
CPC Classifications: F01D,F05D,G01B,G01M,G01N

Claim:
1. A method for in-situ visual inspection of a turbine engine casing interior, comprising: providing a gas turbine including: a turbine casing having an inner circumferential ring segment that fully circumscribes a rotatable rotor oriented within the casing, the rotor having a row of turbine blades radially aligned with the ring segment, each blade having an airfoil that defines an airfoil surface and a radially outwardly projecting tip in opposed spaced relationship with the circumscribing turbine casing, each respective blade tip defining a radial clearance gap between itself and the circumscribing ring segment at a plurality of rotational angular positions of the blade and rotor; directly coupling at least one optical camera having a field of view to the airfoil surface of a first one of the plurality of the turbine blades, the camera capable of capturing camera images in its field of view and generating a camera image data set during rotor rotation; coupling on the airfoil surface of the same first one of said plurality of blades a rotor rotational position sensor that generates a rotational position data set indicative of rotational angular orientation of said first blade relative to the circumscribing ring segment; rotating the rotor so that the blade tip of said first one of said plurality of blades sweeps at least a portion of the circumscribing ring segment, while generating the camera image data set with the camera and a rotational position data set with the rotor rotational position sensor at plural angular positions along the blade tip sweep of said first one of said plurality of blades; acquiring the image and rotational position data sets with a data acquisition system that is coupled to the camera and the rotational position sensor; and correlating camera image relative to angular rotational position of said first one of said plurality of blades with the image and rotational data sets, at plural angular positions along the blade tip sweep of said first one of said plurality of blades in a data analyzer system that is coupled to the data acquisition system.