Research On Modeling And Control Law Of Adaptive Cycle Engine

Adaptive Cycle Engine model is established based on Variable Cycle Engine.But unlike VCE,the ACE's fan-component is called Flade,and the third bypass is added behind it.So that,the bypass ratio of ACE is more wide than the VCE's in the same size,and it brings four new work modes.The ACE is complex fluid machinery,because it contains a variety of geometric components,bypass components and conventional aero-engine components.Therefore,it is very meaningful to set up a mathematical model which can be more accurate and fully described its work,in order to find out the performance characteristics and control law of the ACE.In this paper,the research of modeling,optimization and control law of ACE is produced,through an adaptive cycle engine developed by G.E Company.The detailed contents are described as following:First,the nonlinear mathematical model of adaptive cycle engine is established.Considering the character of Flade,two segments Flade structure is proposed in the course of modeling.According to the static pressure balance of bypass,the engine calculation method is built to meet the different work modes.In the same time,the effects of degree of variable geometry guide vane on compressor and guide angle turbine are considered.For figure out the characters of ACE,the model is used to simulation in steady process,dynamic process and mode transition.Second,the influence of geometric adjustment on the performance of the engine was considered.The effect of bypass ratio,variable vane and overflow resistance on the performance of the engine has launched the detailed analysis.Thirdly,aiming at improving the adaptability of different working modes of the ACE,the variable of the component model is optimized by using the PSO algorithm.Through optimizing the different mode,such as maximum thrust mode,minimum SFC mode and minimum T45 mode,several groups of data of geometric variable were obtained,which can make the different work modes of ACE running in the best performance.Then,based on the data obtained above,different mode switching schemes are proposed.Based on the simulation and verification of different mode switching schemes,a smooth and safe transition scheme is obtained.Finally,the control law of ACE is researched.The simulation platform is designed by Simulink,which provides a platform for the simulation study of the main fuel control,afterburner's fuel control,nozzle throat and outlet area control,the law guide vane angle control and mode switching control.And it indicates that the ACE model can be safe running during starting,acceleration and reheating.