DYNAMICS OF ROTORS IMMERSED IN ECCENTRIC ANNULAR-FLOW .1. THEORY

A theoretical model is developed for predicting the dynamic behaviour and stability of a rotating shaft immersed in both a concentric or ecc entric fluid annulus. Of specific concern here are geometries presenti ng a moderate flow-confinement, for which scarce results exist. Theore tical results show that moderate gap configurations lead to quite dist inct flow forces, when compared to typical bearing configurations. Als o, the annulus eccentricity is shown to be a very important parameter, controlling rotor dynamics and stability. In a companion paper (Part 2), experimental results are reported and favourably compared with the present theory. (C) 1996 Academic Press Limited