Fast response wall pressure measurement as a means of gas turbine blade fault identification

Abstract

The distortions of the pressure field around rotating blades of turbomachinery components due to alterations of their shape, can be utilized for the identification of faults related to the blading. Measurement of the unsteady pressure field in the wall proximity, provides information on such flow and pressure distortions and can thus be used for diagnostic purposes. An experimental investigation of the compressor rotating blades pressure field of an industrial gas turbine has been undertaken, in order to demonstrate the feasibility of the above mentioned principle. Various realistic gas turbine blade faults have been examined. The application of the appropriate processing techniques, demonstrates that unsteady pressure measurements can be used to identify the occurrence of minor blade faults (not traceable by standard techniques) as well as the kind of the fault. The proposed methodology has the potential for being incorporated in a computerized engine health monitoring system.