The Transfer Matrix–Component Mode Synthesis for Rotordynamic Analysis

Author(s):  
Huang Taiping

The transfer matrix–component mode synthesis has been developed for the analysis of critical speed, response to imbalance and rotordynamic optimal design of multi–spool rotor system. This method adopted the advantages of the transfer matrix method for the train structure and the component mode synthesis for reducing degrees of freedom. In this method, the whole system is divided into several subsystems at the boundary coordinates. The constrained vibration modes and the static deflection curves of the constrained rotor subsystems are analysed by the improved transfer matrix method. The whole system is connected together by the component mode synthesis in accordance with the coordinate transformation. Numerical examples show that this method is superior to the traditional transfer matrix method and the component mode synthesis by FEM. This method has been successfully used for the rotordynamic analysis and optimal design of the compressors and the gas turbine aeroengines.

Author(s):  
M. Kobayashi ◽  
S. Saito ◽  
S. Yamauchi

Abstract This paper proposes a new method for steady-state, large-order nonlinear rotordynamic calculations: it uses a method called the transfer coefficient method (TCM), which is more convenient than the transfer matrix method. Since TCM calls for only the displacement as the independent variable, whereas both the displacement and the force are needed as the state variables in the conventional transfer matrix method, TCM promises a substantial saving of computation time without incurring loss in the accuracy of calculation. First, the outline of TCM is explained, then the nonlinear calculations for a rotor of many degrees of freedom are presented. This steady-state nonlinear calculation method is based on the discreet Fourier transform (DPT, FFT) and substructure synthesis. As an example, the nonlinear response due to unbalance mass is calculated and discussed in the case of the rotor which is supported by three bearings with two nonlinear squeeze film dampers.


2019 ◽  
Vol 49 (3) ◽  
pp. 337-354 ◽  
Author(s):  
Xue Rui ◽  
Dieter Bestle ◽  
Guoping Wang ◽  
Jiangshu Zhang ◽  
Xiaoting Rui ◽  
...  

Abstract Computational speed and stability are two important aspects in the dynamics analysis of large-scale complex multibody systems. In order to improve both in the context of the multibody system transfer matrix method, a new version of the Riccati transfer matrix method is presented. Based on the new version of the general transfer matrix method for multibody system simulation, recursive formulae are developed which not only retain all advantages of the transfer matrix method, but also reduce the truncation error. As a result, the computational speed, accuracy and efficiency are improved. Numerical computation results obtained by the proposed method and an ordinary multibody system formulation show good agreement. The successful computation for a spatial branch system with more than 100000 degrees of freedom validates that the proposed method is also working for huge systems.


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