Complex Eigenvalue Analysis of Rotors by the Transfer Coefficient Method

Abstract

This paper proposes a new method for rotor dynamics calculations, called the transfer coefficient method, which is more convenient than the conventional transfer matrix method. By treating only the displacement as the independent variable, where both the displacement and the force are considered as independent variables in the transfer matrix method, this method promises a substantial saving of computational time without loss of the accuracy of calculation. There are two types of transfer coefficient methods. In the first, the coefficients are treated as independent of the vibration frequencies, while in the other, the coefficients are considered dependent on the frequencies. Formulation of a fundamental rotor system and applications for either type are discussed in detail with a bearing box, a branched system, and a multi spool system as examples.