Stability performance of an adjustable multi-pad fluid film bearing profile under load-between-pad orientations

A multi-pad bearing profile incorporated with innovative adjustable mechanism capable of controlling the dynamic behaviour of rotor bearing system is analysed in this study. The film thickness variation occurring under pad displaced conditions are accurately predicted by utilising the developed film thickness equation. The modified form of film thickness equation also takes account of the load positions and quasi-static adjustable pad motions in radial and tilt directions. The present study evaluates the effect of different load positions on the stability performance of multi pad adjustable bearing. Linear perturbation analysis is performed to compute the dynamic coefficients of rotor system. Simulations indicated that the film thickness variation caused by pad adjustments significantly alters the bearing dynamic coefficients and attains an efficient control over bearing stability. For a given load position, negative radial adjustment of pads is found to enhance the stability regions of rotor system than other pad adjusted positions.