Research On Control Technology And Stress Prediction Of Distributed Parameter System Of Turbine Disk With Time Delay

With the development of China's aviation industry,the demand for heat treatment technology of plate blank is higher and higher.The traditional quenching method has many problems,such as large residual stress,uneven temperature field,and difficult to control the temperature drop rate.However,the gas impinging jet quenching method used in this project can control the heat transfer by changing the flow rate of the nozzle to adjust the convection heat transfer coefficient of the disc,so as to keep the temperature drop rate constant.The quenching method of gas impinging jet has the advantages of parameter controllability,cleanness and small residual stress.It can realize the quenching of the plate blank at the preset temperature drop speed,so as to ensure the metallographic structure of the plate blank and improve the mechanical properties of the plate blank.Based on the principle of gas impingement jet quenching,the temperature field uniformity control and stress prediction of the disk with time delay are studied as followsFirst of all,the distributed parameter system has infinite dimensions in the state space,and the control mode of gas impingement jet quenching is point control.In order to use the state information of finite points to replace the distributed parameter system,it is necessary to identify the distributed parameter system by the way of orthogonal function approximation,and solve it by the optimization criterion of minimum observation matrix error.The control points of the distributed parameter system in the process of gas impinging jet quenching are selected.Secondly,based on the principle of flow field simulation parallel computing,a simulation platform of three-dimensional parallel computing of gas impingement jet quenching based on the joint simulation of controller control is built;and the control system of time delay distribution parameter system of gas impingement jet quenching based on Fuzzy PI Smith control is established in combination with the selected control points.At last,the thermal stress simulation platform of fluid structure coupling and thermal force coupling is built.The elastic-plastic model of plate blank is established,and the stress prediction results of constant flow rate of gas impinging jet quenching and the stress and measurement results based on Fuzzy PI Smith control are compared.The results show that the control system can effectively reduce the residual stress of the disc blank.