A simplified method for the correction of velocity slip and inertia effects in porous aerostatic thrust bearings

Inertia effects in porous material, as well as velocity slip at the porous bearing surface, have hindered the use of simple mathematical models for the analyses of porous aerostatic bearings. Experimental evidence indicated that velocity slip at the porous surface did not obey the Beavers model, but could be approximated by an added equivalent clearance. This experimentally determined clearance value did not bear any direct relationship with the surface roughness of the test specimen. Good agreement between theoretical and experimental results of static load capacity of a porous ceramic test bearing, however, demonstrated the use of this equivalent clearance method, in conjunction with a proposed approximation to correct for inertia effects, as an effective modification to the simple one-dimensional model by Sheinberg.