Gas Turbine Performance Prediction by Using Generalized Performance Curves of Compressor and Turbine Stages

Abstract

The paper presents a method for gas turbine performance prediction which uses compressor and turbine performance maps obtained by using generalized stage performance curves matched by means of the “stage–stacking” procedure. In particular, the overall multistage compressor performance is predicted using generalized relationships between stage efficiency, pressure coefficient and flow coefficient, while the multistage turbine performance is predicted by modeling each turbine stage by a series of two nozzles, a fixed one (stator) and a moving one (rotor). The characteristic of the proposed method is that the unknown parameters defining the generalized stage performance curves are determined by combining a Cycle Program with the compressor and turbine performance maps obtained using the “stage–stacking” procedure, and by searching for the values of the unknown parameters which better reproduce, by means of the Cycle Program, the overall performance and thermodynamic data measured on a gas turbine.