For a hydrodynamic foil thrust bearing with hemispherical convex dots

the compressible fluid Reynolds equation is adopted

where the inner flow is assumed as laminar and

the pressure remains constant along the gas film thickness

and fluid volume force and inertial force are ignored. Finite difference method(FDM)is adopted to numerically solve the Reynolds equation to obtain the pressure distribution under isothermal condition. By sufficiently considering deformation of the hemispherical convex dots under pressure

the model of fluid-structure coupling is used to analyze the interaction between the deformation of the top foil and pressure

and the deformation of top foil and clearance distribution of the gas film are sought out by combining with the thin plate bending model to discuss the effects of bearing number and structure parameter of foil on bearing performance. It indicates that the inappropriate position of supporting structure affects the pressure distribution of gas film directly and weakens the bearing performance; the bearing performance is improved by increasing bearing number

ratio of inlet and outlet gas film clearance and ratio of inner and outer bearing diameter. The optimum performance can be reached at pitch ratio of 0.5.