Linear Transient Response of a Flexible Rotor Supported in Gas-Lubricated Bearings

Assuming sufficiently small journal amplitudes, a rotor supported in gas-lubricated bearings represents a nonconservative, nonself-adjoint system with frequency dependent support coefficients. A method is developed to compute the complex eigenvalues together with the associated modal and adjoint functions for such a system for use in establishing normal coordinates. On this basis, the response to any arbitrary excitation is readily obtained. The application of the method is illustrated by calculations of the response to shock excitation and external random vibration of a rigid rotor supported in tilting pad bearings.