Research On The Dynamic Behavior Of The Central Rod-fastening Rotor

Gas turbines are widely used in power generation,aerospace,portable power supply,turbine compressor and other fields.And its key component,the central rod-fastening rotor,has the advantages of high rigidity,high strength and convenient processing and manufacturing,etc.,and much attention has been paid by many scholars of the rod-fastening rotor-bearing system.In this dissertation,the central rod-fastening rotor is taken as the object,and the dynamic characteristics of the system is analyzed.The main contents are listed as follows:1.Considering that the wheel disks are contacted by end teeth,the contact shaft is modeled by Euler beam,and the stiffness and related stiffness coefficients are analyzed.Similarly,each part of the central rod-fastening rotor is modeled by Euler beam,and the equation of motion of the beam element is derived.The dynamic model of the rod-fastening rotor is established.2.The microscopic roughness of the rotor contact surface is analyzed,and the corresponding contact model is established.At the same time,the lumped parameter method is used to modify the bending stiffness with contact surface,the overall bending stiffness of the elastic shaft section of the contact surface is derived,and the corresponding contact correction coefficient is obtained.Then the prestress saturation of the rotor is studied,combined with the lumped parameter method,the equivalent bending stiffness of the beam under the prestress is derived,and the corresponding prestress correction coefficient is also obtained.The actual contact conditions of the two impellers under different conditions are studied,and the specific contact conditions between adjacent wheels are obtained.3.Based on the finite element model,the modal characteristics of the rod-fastening rotor and each part of the rotor are analyzed,and the first ten natural frequencies and various modes of vibration are obtained,as well as maximum and minimum amplitude positions are also obtained.Then,the static contact analysis is implemented to obtain the contact status of the rotor system under different contact conditions.According to the thermal analysis in different temperature fields,the corresponding temperature cloud map and total heat flux cloud map of the rod-fastening rotor are obtained.4.For a class of nonlinear dynamic systems,the conditions that the coupling function needs to satisfy is given.A control method is used to eventually make the response consistent by unction coupling to achieve chaos synchronization.Based on Duffing system and Mathieu system,the feasibility of this method is verified by simulation experiments.Anti-synchronization of the original system and the derived system can also be achieved.The dynamic synchronization control of the system support response during the operation of the rotor system is derived,which provides the basis for the synchronization of the rotor system.The above works provide reference for the follow-up dynamics of the rod-fastening rotor system.