Research On Component Level Modeling And Solution Optimization Method For Single Spool Turbojet Gas Turbine

The modeling technology of aviation gas turbine can save the time and economic cost of developing aviation gas turbine,and its modeling accuracy is an important index to measure whether the model is meaningful or not.Because the gas turbine components are affected by the installation technology,component tolerances,component losses and other factors,the component characteristics between the actual gas turbine and its model may have significant differences,resulting in low accuracy when solving the model.To address this problem,this paper takes the single spool turbojet gas turbine as the research object,establishes the component level mathematical model of this type of gas turbine,and optimizes the solution method to improve the accuracy of the model solution.Three main aspects of research work are carried out as follows:(1)The steady and dynamic models of the turbojet gas turbine are established by the component method,and the traditional N-R iterative solution method is improved to enhance the convergence of the model solution.One design point and six off-design points are selected to verify the accuracy of the steady and dynamic models.The same operating points are simulated using Gas Turb software and analyze the causes of errors.(2)In order to improve the solution accuracy of the gas turbine model,the solution method is optimized by using the improved PSO algorithm to find a set of suitable optimization coefficients and optimizing the component characteristic diagrams of the compressor and turbine to improve the accuracy of the component characteristic diagrams and thus the solution accuracy of the model.Different optimization methods are designed for the steady model and dynamic model respectively.For the steady model,the whole optimization method is used,and a sampling algorithm is proposed to remove the redundant data points in the component characteristic diagram by using the vertical distance as the standard,so as to improve the accuracy and efficiency of the interpolation model calculation.For dynamic model,local optimization method is used to determine the area where the off-design points are located based on the design points,and different optimization rules are set for each area to optimize the component characteristics,so as to ensure that the accuracy of the model solution will not be affected under the optimized working points.(3)To verify the optimization method of model solving,the corresponding module is built on Matlab/Simulink platform for simulation calculation.The simulation results show that the average relative error of each parameter is reduced from 3.5175%to 0.3778% for the steady model solution,and the average relative error of each parameter is reduced from 2.7413%,2.481%,1.9785%,3.0249%,3.1835%,2.8629% to0.3290%,0.3628%,0.2950%,0.4428%,0.4982%,0.4654% for the dynamic model solution under the six off-design point operating conditions.The above results show that after optimizing the solution method,the steady model as well as the dynamic model satisfies the requirement that the average error is less than 1% when solving,which indicates that the optimization method proposed in this paper is effective and feasible.