Modeling Research Of A Certain Type Of Aero-engine Fuel Metering System

A certain type of aviation engine fuel metering system has a mismatch,and it cannot issue accurate fuel metering and command fuel on demand.In view of this phenomenon,a mathematical model of the fuel metering system needs to be established and analyzed.Both valve spools have a certain degree of disturbance,which is inseparable from the pressure at the two valve spools.However,the treatment of pressure variables in previous studies is relatively simple,mainly because in actual work the pressure at the two valve spools is relatively simple.Pressure data is difficult to obtain.For this reason,it is proposed to use the CFD+time series method to establish the pressure prediction model of the spool.Use the CFD method to obtain the pressure data of the two spools,and then use the time series to model it.Specifically,the threedimensional model of the system is established in CAD,imported into CFD for meshing,the system is numerically simulated using the large eddy simulation model,and a monitor is set at the two valve cores to record the pressure of the two valve cores,and the two valve cores are recorded.The spool pressure value is 1000 each.Then use time series analysis method to analyze the obtained pressure sequence,including outlier processing,stationarity test,pure randomness test,model identification,model optimization and model test,and get the prediction model of two spool pressure.Considering the integrity of the system,the prediction models of the pressure of the two spools when the system opening is 3mm,6mm,9mm and 12 mm are established respectively.The obtained model is predicted and compared with the original sequence.The results show that the root mean square error of each model is less than 1.According to the mathematical model of the system,a simulation platform is built in MATLAB and the pressure model of the two spools at 4 openings is used as the system input,and the system is simulated.The results show that the fuel metering system does not match in most cases The phenomenon,that is,the inability to provide accurate metered fuel and command oil as required,is consistent with the actual situation of a certain factory,and further verifies the accuracy of the model established in this article.The mathematical model of a certain type of aviation engine fuel metering system established in this paper laid the foundation for the subsequent rectification of the system by a certain factory.