Side clearance effects on squeeze film damper performance

Computational fluid dynamics has been used to study the influence of end se al clearance and flow path length on the performance of a circular orbiting squeeze film damper with a central circumferential feed groove. Results in dicate that to be effective in modifying the damper stiffness and damping c haracteristics, the axial clearance between the damper and the seal needs t o be of the same order of magnitude as the radial clearance of the damper i n its housing. The pressure distribution is predicted to remain close to a pi-film, regardless of seal clearances, and oil flow patterns are also give n. It is concluded that over a narrow range of axial seal clearances, the d amper performance is very sensitive to the axial seal clearances; and that over this range, the vibration behaviour of squeeze film damped rotor-beari ng systems incorporating such axial seals will be significantly influenced by machining and assembly tolerances. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.