Instrumentation and measurements play a very special role in the advancement of gas turbine turbomachinery. In an industrial gas turbine experimental program, testing constantly flanks machine development and full-load testing of extensively instrumented units provides information on both overall and component performance.
Rotordynamic testing is performed to determine, in ambient conditions, the optimum configuration for the rotor-bearing-casing assembly.
Fluid-dynamic testing on models of the inlet duct, turbine casing and transition piece assembly and blade cooling system is carried out to minimize flow distortions or optimize cooling flows.
Stress and modal analyses on turbine and compressor blades are performed, using 3D photoelasticity and holographic interferometry.
In the full-load testing, the measurements include thermodynamic values, temperatures of the components, blade vibratory strains, blade tip clearances and axial displacements.
Signals from rotating thermocouples and strain gages, installed on both turbine and compressor rotors, are transmitted using slip ring systems. HP blade temperature distribution is measured by means of the infrared pyrometer.
Typical Campbell diagrams are derived from the blade strain gage measurements and are used for HCF verification.
Radial and axial stator-to-rotor displacements are measured during transients.