Research On High Fidelity Modeling And Starting Performance Simulation Of Aeroengine

The starting process is one of the most complex dynamic processes of aeroengines.Civil high power aeroengines often use gas turbine starters as starting auxiliary equipment.Gas turbine starter also have a starting process.Due to the complexity of the start-matching simulation process of the two,the starter is generally simplified at home and abroad,and the performance of the starter is approximated by the external characteristic curve or semi-empirical formula,then the start-up simulation research is carried out.The reliability of the aeroengine starting process and the length of the start-up time are closely related to the performance of the gas turbine starter.Therefore,it is of great significance to carry out simulation research on the start-up matching of the gas turbine starter and the aeroengine.In view of the above mentioned facts,this paper conducts the following research about the starting simulation method of aero-engine and gas turbine starter matching.(1)This paper takes two-spool mixed flow turbofan and gas turbine starter as the research object,and establishes their high fidelity component level simulation model.A new calculation method for the thermodynamic properties of ideal gas mixture based on enthalpy and entropy is developed to analyze the influence of humidity and flue gas on the working fluid’s thermodynamic properties.In addition,the effects of humidity and flue gas on the component characteristics of engine are discussed.The results show that with the increase of humidity or flue gas,the engine thrust decreases,the air flow decreases,and the fuel consumption increases.(2)Based on similarity theory of the incompressible fluid,this paper will use the existing above-idle characteristics to extend the sub-idle characteristics.To resolve the interpolation problem auxiliary coordinates,the so-called Beta-lines,are introduced.Then,research on a Beta line-based characteristic curve encryption processing method and characteristic interpolation calculation method,and discuss the characteristic curve scaling processing method of turbomachinery components.(3)Analyze the starting process of matching turbofan engine and gas turbine starter,the switching strategy of open and closed loop fuel supply rules and the selection of initial guess value of starting,and establish the starting simulation model of matching turbofan engine and gas turbine starter.The simulation results can better reflect the starting process of gas turbine starter and turbofan engine.(4)Three typical component faults include starter power decline,fuel system failure and compressor efficiency decline,are simulated by engine starting model and the influence of these faults are analyzed according to the simulation results so that we can explore the simulation conditions of starting failure.