Influence of pad compliance on nonlinear dynamic characteristics of tilting pad journal bearings

Nonlinear dynamic behaviour of vertical and horizontal rotors in compliant liner tilting pad journal bearings: Some design considerations

“…Pressure at the pad edges is set to ambient. A density-pressure cavitation model is implemented as shown in [8,9]. Saturation pressure is set to 20 kPa.…”

“…The final results are not noticeably affected by a further increase in the number of nodes in the pad backing and compliant liner. Since the pads are small, pad inertia does not affect the final results as shown in [9,11]. Convergence criteria for pressure and displacements are set to 10 À 7 Pa and 10 À 7 m. The convergence criterion of 10 À 9 was used to verify the accuracy of the final results.…”

“…Tilting pads with compliant liners also show similar trends when supporting a horizontal rotor. Deformation of the compliant liner due to hydrodynamic pressure results in much thicker minimum oil film thickness in the pad mid-plane compared to white metal pads [9].…”

“…In this paper we study the effect of alternative liner materials on bearing response. Such materials are elastic polymers, and as previous studies showed [1][2][3][4][5][6][7][8][9], provide significant advantages over white metal. For example, a polytetrafluoroethylene (PTFE) liner reduces break-away friction during start-ups [1].…”

Nonlinear model identification of oil-lubricated tilting pad bearings

“…A prevalent approach to model the nonlinearities in the TPJBs is solving the Reynolds equation for nonlinear forces and moments in the TPJBs using numerical integrations. Several researchers adopted this approach in order to evaluate the transient unbalance response of rotating systems supported on various TPJBs [19][20][21][22][23][24][25][26][27][28][29][30]. In a different study on transient behavior in TPJBs [31], an analytical model based on the short bearing theory has been proposed to calculate the nonlinear forces of a TPJB including the turbulence effect, and a comparison has been made between analytical models with and without this effect.…”