Experimental and CFD study on the mass flow-rate characteristic of gas through orifice-type restrictor in aerostatic bearings

This paper describes the experimental and CFD study on the mass flow-rate characteristic through an orifice-type restrictor in aerostatic bearings. In the conventional design of gas-lubricated aerostatic bearings, the mass flow-rate of gas through an orifice-type restrictor is generally derived from a well-known mathematical model, which is originally developed to describe the mass flow-rate property through an ideal nozzle. It is reasonable to doubt if there is any difference between the property of mass flow-rate through an orifice and that through a nozzle. In this paper, therefore, a series of simulations and experiments are carried out and the results show that the mass flow-rate characteristic through an orifice is different from that through a nozzle. Consequently, the conventional model to determine the mass flow-rate through an orifice-type restrictor in aerostatic bearings may have to be updated to the proposed new model for more precise design and modelling of the gas-lubricated aerostatic bearings.