COMBINED EFFECTS OF FLUID INERTIA AND GAS RAREFACTION ON THE PERFORMANCE OF TEXTURED GAS BEARINGS

Considering the significant discretization effort required to describe texture shapes and possible strong fluid recirculation phenomenon in the deep textured area, this paper attempts to solve the above two hurdles by introducing the multigrid method and inertial correction operation. Furthermore, the first-order slip model and perturbation method were adopted to incorporate gas rarefaction and inertia terms in the compressible Reynolds equation. Moreover, the finite difference method and multigrid algorithm were employed to discretize the pressure governing equations and quickly reduce the iterative residuals of linear systems of equations, respectively. The effects of rotational speed, eccentricity, nominal clearance, state of the lubricated surface, and texture parameters on the static performance of gas bearings were studied. On this basis, the CPU time statistics results show that the computing efficiency of multigrid can be increased by more than 46% compared with the traditional direct solution under the same operating parameters. In addition, it is observed that slip flow and fluid inertia usually reduce the predicted load capacity of gas bearings, and the effect of fluid inertia is stronger than that of the slip flow when the rotational speed is high, the clearance is large, and the dimple texture is deep. The above study supports textured foil journal bearings’rapid and accurate design in the following engineering practices.