Jet engine component maps for performance modeling and diagnosis

This paper describes an effort to model the performance maps of compressors and turbines (i.e., the relation between mass flow, pressure ratio, and efficiency), using analytical functions. Analytical functions are fitted to the available experimental data using a least-squares-type approach for determining the parameters of the fitting function, The success of using a particular function for an application is assessed through a suitably defined mean error of the model, Apart from presenting the method for setting up these analytical representations, applications to performance modeling and fault diagnosis are discussed. The change in model parameters is used to characterize changes of the engine condition and possibly diagnose occurring faults. The impact of introducing analytical component models into overall engine computer models, replacing a tabulated form of the component maps, is also discussed.