Research On Adaptive Cycle Engine Modeling And Mode Switching Control Schemes

Adaptive cycle engine is the key development direction of advanced fighter engine in the future.In this paper,the whole engine modeling and mode switching control plan research are carried out for a three bypass adaptive cycle engine.The main work is as follows:Several adaptive cycle engine configurations at home and abroad are reviewed,and one of them is selected as the research object to carry out the research of engine modeling method.According to the published literature at home and abroad,the performance index design requirements and the overall cycle parameter range of the adaptive cycle engine are determined;the design point parameter design model of the adaptive cycle engine is established by using the aerodynamic thermodynamics method,and the design point parameters of the adaptive cycle engine under two working modes of single bypass duct and three bypass duct are selected,which meets the performance index requirements It lays a foundation for the subsequent development of adaptive cycle engine component level modeling.According to the selected configuration and design point parameters of the adaptive cycle engine,the component level simulation model of the adaptive cycle engine is established by using the general component characteristics.Aiming at the problem of the number of common working equations of the engine model when the third bypass duct is opened,a method of selecting the dynamic simulation initial guess value of blade tip pressure ratio of the blade of the fade fan is proposed to realize the engine mode switching The transient performance simulation of the engine.The multi-point steady-state simulation of single and three bypass duct modes of adaptive cycle engine is carried out by using the whole model.The dynamic simulation of four working modes is carried out,and the transient-state simulation of all flight envelope points of single bypass duct mode is carried out.The results show that the calculation results of the self-adaptive cycle engine are reasonable,with high real-time performance and good convergence.Based on the established model of the adaptive cycle engine,the influences of the area of the FVABI and RVABI,the opening of the MBSV,the area of the inlet duct in the mixing chamber and the change of the ratio of the intake and the exhaust on the engine performance are analyzed by simulation.The acceleration control law,the intermediate state and the above force control law of the adaptive cycle engine are studied and formulated The simulation results show that the transition process of the engine is smooth,the fluctuation is small,and there is no over rotation and over temperature phenomenon.The effectiveness of the engine performance model and control law simulation module is preliminarily verified.Based on the established component level model of the adaptive cycle engine,the simulation research of six modes switching open-loop transition state under different working conditions is carried out,covering all working modes of the adaptive cycle engine;the closed-loop switching simulation test is carried out to keep the high and low-pressure rotor rotating speed constant during the mode switching process,which preliminarily verifies that the model has the ability to carry out the closed-loop mode switching Simulation ability: in view of the problem of large thrust fluctuation in the model mode switching process,two improved control plans of mode switching are proposed,which preliminarily realizes the mode switching control of constant thrust.