COMPUTATIONAL AND EXPERIMENTAL ANALYSIS OF AN INDUSTRIAL GAS TURBINE COMPRESSOR

Test rig results and their comparison with computational analyses of a highly-loaded 11-stage compressor for a newly developed industrial gas turbine will be presented in this paper. The scope of the tests has been validation of aerodynamic and mechanical features of the bladed flow path to meet both the demands for single- and dual-shaft operation of the gas turbine. The test was carried out in three phases using extensive instrumentation. In phase 1 the front stages have been tested, and in phase 2 the test of the full 11-stage compressor was performed including numerous aerodynamic and structural check-outs. Vane and blade vibration modes were measured in all rows with numerous strain gauges using a telemetry system and Tip Timing, which additionally was applied to the front stage rotors. Concerning the mechanical design, finite element predictions of the vibration modes of all blades and vanes were carried out in the design phase to guarantee safe and resonance-free operation for a wide range of operational speeds which could be verified by the test data up to higher modes. Flow field computations were carried out with both a through flow solver and full 3-D viscous multistage solver based on Denton's TBLOCK, where all rotor and stator flow fields had been solved simultaneously and compared with experiments. The effects of tip clearance and stator cavities on compressor performance have been taken into account by the computational analysis. Effects of inlet distortion were examined in phase 3. Comprehensive comparisons of computed and measured results will be presented. The extensive instrumentation gave also insight into flow details as vane pressure distributions and total pressure profiles in span wise direction. It will be shown that the agreements of predicted and measured data were excellent.