A numerical scheme for the thermodynamic analysis of gas turbines

Abstract

In this work we present a numerical scheme for the steady-state thermodynamic analysis of gas turbine engines. As usual in the literature, it is based on modelling the gas turbine as a set of independent components connected through nodes, thus giving the user great flexibility to modify the gas turbine’s model and to define and include new components. Additionally, the proposed method provides the same flexibility for the inclusion of new gas properties calculators and nonlinear equations solvers. The simulator also allows identifying the characteristic parameters of the different components of the gas turbine –such as the compressor’s nominal pressure ratio and efficiency– from a batch of operation data. The latter task is accomplished by means of a systematic and computationally economic procedure which allows that the parameters identification be performed component-by-component and does not require any full gas turbine simulations. The scheme has been formulated so that it exploits the full capabilities of today’s computers and mathematical techniques –such as sparse matrix solvers and quasi-Newton methods for sparse jacobians– but, at the same time, remains simple enough to be self-implemented by the interested researchers with the aid of general-purpose mathematical computing software such as Matlab. The simulator has been applied to predict the performance of a real gas turbine, obtaining excellent results.