Dynamics analysis of magnetic levitation rotor of

Dynamics analysis of Maglev rotor of high temperature gas cooled reactor

the Institute of nuclear energy and new energy technology of Tsinghua University has undertaken the research and research of the national key project "high temperature gas cooled reactor helium turbine power generation" in the tenth and eleventh five year plan. The most important key technology in this project is electromagnetic suspension bearing, which mainly solves the lubrication and over critical problems of rotating parts in high temperature environment

rotor structure design and rotor dynamics analysis are the most important links in the design of the whole electromagnetic suspension bearing system. First of all, the rotor must be structurally controllable and stable within a certain speed range. Therefore, it is necessary to carry out modal analysis, eigenvalue analysis, excitation response analysis, etc. of the rotor with speed, and finally determine the layout scheme of the overall structure of the electromagnetic bearing system and the parameters of the control system according to the results of the machine analysis of the high-precision microcomputer controlled pressure experiment developed by Jinan assaying specialty

project challenge:

accurate rotor dynamics analysis is a crucial link for the design of electromagnetic levitated bearing rotor system, which is related to the success or failure of the whole system design. However, the special Rotordynamics analysis software that has been using the transfer matrix method for calculation for a long time cannot carry out accurate modeling, and most general finite element software does not provide relevant calculation modules. These problems have not been well solved, and the design, calculation simplification and simulation results analysis rely more on experience

solution:

the fixture required by be provided by ANSYS is 5-flower 8-door AM4 and pipe16 units, which can carry out one-dimensional rotor dynamics analysis with speed and corresponding excitation analysis

Figure 1 modal analysis

the modal analysis of the fine structure part at 0 speed can be carried out by using the three-dimensional solid model, and the corresponding model simplification in the one-dimensional calculation can be checked to calculate the equivalent stress under each mode

Figure 2 modal analysis

in the latest version of ANSYS, it also provides new functions for drawing Campbell graphics and judging stability. The comprehensive application of these analysis functions basically meets the requirements of structural design for the popularization of rotor dynamics analysis

Figure 3 excitation response analysis

by using APDL language to write a general rotor dynamics analysis software package, you can quickly complete all general analyses related to the rotor by modifying the model parameters in the input file, which greatly shortens the cycle of structural analysis

user value

it can complete almost all analysis functions related to system development on one software platform, especially rotor dynamics analysis, which is impossible for any other software of the lamp. In the research and development of the project, the consistency of simulation platforms of different developers is maintained, the analysis process is accelerated, and the investment in human physics is reduced. In terms of calculation results, its accuracy basically meets the application requirements, and the powerful post-processing function provided by ANSYS makes the observation of analysis results more intuitive and flexible, and it is easier to make correct judgments in the design

customer evaluation:

due to the influence of rotor internal stress and rotating Coriolis force, the modal frequency and modal shape of high-speed rotor will change with the increase of rotating speed. This kind of analysis function is not provided in many general finite element software, while the special finite element software can only provide very limited analysis modules and can not carry out other analysis further. Using ANSYS, we can better analyze the dynamics of the rotor model with speed, and do further equivalent stress analysis, excitation response analysis, etc., which better meets the needs of the project research. (end)