DEVELOPMENT OF A TRANSONIC FRONT STAGE OF AN AXIAL-FLOW COMPRESSOR FOR INDUSTRIAL GAS-TURBINES

This paper describes the aerodynamic blade design of a highly loaded t hree-stage compressor, which is a model compressor for the front stage of an industrial gas turbine. Test results are presented that confirm design performance. Some surge and rotating stall measurement results are also discussed. The first stator blade in this test compressor op erates in the high subsonic range at the inlet. To reduce the pressure loss due to blade surface shock waves, a shock-free airfoil is design ed to replace the first stator blade in an NACA-65 airfoil in a three- stage compressor. Comparison of the performance of both blades shows t hat the shock-free airfoil blade reduces pressure loss. This paper als o presents some experimental results for MCA (multicircular are) airfo ils, which are used for first rotor blades.