Research On Ground Start Modeling And Control Law Optimization Of Civil Turbofan Engine

Since our country first proposed the goal of developing a large domestic civil aircraft,we has continued to promote the development of high bypass ratio civil turbofan engines.As a long-period,high-cost and high-risk industrial technology product that integrates top technology,it is a great research significance to replace its semi-physical experiment with high-precision computer simulation technology.Therefore,this paper studies the modeling technology of the process from engine startup to idle speed,and conducts method optimization exploration for its control law under the idle state on the ground.First of all,this article analyzes the basic technical requirements of high bypass ratio civil turbofan engines based on the structural characteristics,technical parameters,performance parameters and thermal cycle parameters of foreign advanced civil turbofan engines.Taking the JT9 D engine as the research object,NASA disclosed the characteristic data above the slow speed of the idle state.Taking into account the diameter of the fan,the fan blade tip and blade root were modeled separately,and a component-level model was built.The model was extended to the below idle state by extrapolating the characteristic data.The simulation experiment simulates the process from engine start to idle speed,which verifies the validity of the model.Secondly,based on the built model,the engine control method under the idle state on the ground is studied.The application of traditional proportional-integral-derivative(PID)control in the field of aeroengine control is studied,and the control parameters of the engine are restricted and managed by connecting limiters in series.The simulation experiment verifies the control effect of the control logic,and analyzes the shortcomings of the traditional proportional-integral controller and the limiter in series.In addition,through the adjustment experiment of PID parameters,the dynamic parameter response of the engine under different adjustment parameters is compared.Finally,this paper studies the advanced control thought method,aeroengine limit management control based on the model predictive control(MPC).The model linearization controller linearizes the established model to obtain the state space equation.The MPC control logic and the realization principle of limit management control are analyzed,and the series connection limiter is omitted in the structure,which reduces the complexity and improves the system reliability.The MPC control logic is applied to the non-linear JT9 D component-level model,and the dynamic response effect of the controlled parameters of the engine is verified through simulation experiments,and the reliability is confirmed.The comparison with PID control effect proves the advantages of MPC in control ability and makes up for the shortcomings of traditional control methods.