The Transient Response of a Journal in Plane Hydrodynamic Bearing with Flexible Damped Supports During Acceleration and Deceleration Periods

Abstract

This paper presents an assessment of the stability margin of plane hydrodynamic journal bearing systems mounted on flexible damped pedestals. The stability margin expressed in terms of critical speed (or critical mass) of journal are obtained using the conventional linearized theory. The assessment investigations are then carried out by delineating the motion of an accelerating or decelerating journal. This involves time marching solutions of the equations of motion of the journal and the bearing coupled with the Reynolds equation. It has been found that the motion of an accelerating or decelerating journal concurs with linearized theory in the stable region. However, at the accelerated speeds in the unstable region, the journal and bearing may either execute low amplitude limit cycles or become unstable. This work also furthers the ideas concerning the limiting speed as developed in an earlier work of the present authors.