Gases as Lubricating Fluids

Gases as well as liquids belong to the general category of fluids, and like liquids, gases can sustain pressure and flow viscously. Hence it is possible to establish a film of gas for lubricating purposes by the same basic actions involved in liquid film lubrication. 

In Chapter 3 it was demonstrated that one form of the generalized Reynolds equation is given by the expression below (c . Eqn 3-34), 

In the absence of a relative velocity U between the two bounding surfaces, the gas film that separates them must be maintained by the flow of gas from a pressurized source external to the bearing system. 

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