Discrete-Time Modelling of a Squeeze-Film Bearing

This paper describes the application of a discrete-time approach to the estimation of the linearized velocity coefficients of a squeeze-film bearing. It is assumed that motions in the vertical and horizontal directions are uncoupled. Sampled observations from laboratory experiments are processed digitally to yield estimates of the parameters in a vector-matrix difference equation. A transformation applied to this equation produces direct estimates of the oil-film coefficients. Verification of the estimated coefficients is achieved through the prediction of the dynamical behaviour of the bearing. In this way, the effectiveness of the experimental models is assessed and compared with predictions based upon short, uncavitated bearing theory.