Analysis of gas lubricated foil thrust bearings using coupled finite element and finite difference methods

Load performance of gas lubricated, compliant surface Soil thrust bearings has an interlocking relationship with the compliance of the bearing and hyd rodynamics of convergent wedge surface. Compliance of the bearing consists of supporting spring elements (elastic foundation) and a smooth elastic top foil. In this paper a class of gas lubricated foil thrust bearings has bee n investigated analytically utilizing a novel approach which combines Finit e Difference (FD) and Finite Element (FE) methods. Solution of the governin g hydrodynamic equations dealing with compressible fluid is coupled with th e structural resiliency of the Soil bearing surfaces. FD method is utilized for hydrodynamic analysis while FE is used to model structural resiliency. Influence coefficients were generated to address the elasticity effects of combined top Soil and elastic foundation on the hydrodynamics of thrust be aring, and were used to expedite the numerical solution. Within 2 to 3 iter ations the convergence criterion was reached The overall program logic prov ed to be an efficient technique to deal with the complex structural complia nce of various foil bearing. Case study has been conducted and sample solut ions are provided. Unlike prior analytical investigation, the essential eff ect of the top foil on the performance of the bearing has been elucidated.