A dynamic model for the distributed simulation of a turbojet engine

Two types of models are currently used in the design of turbo-machines. Steady state performance models, calculate very accurately the compression, expansions and combustion taking place in the thermodynamic cycle. One of the key variables is the compression efficiency. Compression ratio and compression isentropic or polytropic efficiency are function of the rotation rate and axial mass flow rate. Control models use dynamic models based,on simplified dynamic models such as the Moore-Greitzer 3-state model (MG3). Such models represent the compressor performance with a simple cubic law, disconnected to a large extend from the accurate steady state performance models. In this paper a model combining both types of models is developed This model is an accurate performance model, modeling the time variation of axial mass flow rate and pressure ratio, as this is done in the MG3 model, but with a physically based real time modeling of compressor operation. Message passing parallel computing strategy, supported by transputer type architecture is envisaged to provide a time response commensurate with the needs of control designers.