STEADY-STATE AND TRANSIENT DYNAMIC SIMULATION OF A CONTINUOUS FOIL BEARING

The objective of this paper is to present an integrated procedure whic h will analyze the dynamics of a foil bearing on elastic supports. A c omplete time-dependent Navier-Stokes formulation is used to solve for the interaction between the hydrodynamic effects of the fluid lubrican t, the motion of the journal, and the deformable foil boundary. The el astic deformation of the foil and its supports are simulated by a fini te-element model. The steady-state quasi-transient and full transient dynamics of-the-foil-journal interaction are examined. For the steady- state simulation of a particular journal position, the fluid lubricant pressures are evaluated by means of a joint iterative scheme until co nvergence is achieved in both the fluid pressure and the corresponding foil deformation. For the quasi-transient case, the transient motion of the journal is calculated using a numerical integration scheme for the velocity and displacement of the journal. The deformation of the f oil is calculated through numerical iteration in the feedback mode in. combination with the fluid film pressure generated by the journal mot ion, until convergence at every time step is achieved. For the full tr ansient simulation, a parallel real-time integration scheme is used, a t each lime step, to simultaneously evaluate tile new journal position and the new deformed shape of the foil.