Abstract：To investigate the static characteristics of porous aerostatic journal bearings under compressible flow, the flow model of porous journal bearings is established based on the Reynolds lubrication equation, Darcy equation for porous material and gas pressure-density equation. A Laplace-Neumann virtual node method is introduced to address the axial end face pressure boundary conditions of porous journal bearings. This method is coupled with the finite difference method, relaxation iterative method, and pressure-density coupling iterative method for the numerical solution of the flow model. The effects of radius clearance and supply pressure on the static characteristics under compressible flow is examined and compared with the outcomes derived from incompressible flow computations. The results indicate that, at a consistent minimum film thickness, the load capacity, mass flow rate, and power consumption for both compressible and incompressible flows exhibit an augmentation with the increasing values of radius clearance and supply pressure. Under compressible flow, the load capacity at radius clearance of 0.01 mm and 0.03 mm is less than incompressible flow, and at radius clearance of 0.05 mm is greater than incompressible flow. While the mass flow rate and power consumption under compressible flow are greater than incompressible. This study could provide a reference for the design and fast calculation of porous journal bearings.
