Synchronous steady state response of an overhung rotor with squeeze film damping

An analytical method is developed for treatment of a typical system in which the outrigger bearing of an overhung rotor is provided with a squeeze film damper supported in a flexible casing. The rotor and stator of multiple degrees-of-freedom are handled with convenience by a “polar receptance matrix” method. A characteristic equation is derived which governs rotor-stator interaction either with dry contact or through a squeeze film damper. For the nonlinear squeeze film action solutions based on “mobility” information of a dynamically loaded journal bearing are obtained facilitating a general approach. A computer programme is written in Fortran for steady state response of the system in terms of whirl, position and force vectors, trial runs of which indicate complex behaviour of a squeeze film damped system.