Numerical Calculation of Pressure Distribution in the Bearing Clearance of Circular Aerostatic Thrust Bearings with a Single Air Supply Hole

Abstract

This paper describes the pressure distribution in the bearing clearance of circular aerostatic thrust bearings with a single air supply hole. In case of high air supply pressure or large bearing clearance, it was reported that shock wave occurs and forms complex fluid structure in the bearing clearance. However, it is very difficult to obtain the information of flow structure in detail from flow visualization because of very narrow bearing clearance. Therefore, we calculated the flow field using computational fluid dynamics (CFD) instead of Reynolds equation and supersonic flow model. In addition, we measured pressure distributions in the bearing clearance. It was consequently found that shock wave does not occur near a feeding hole, and air flow changes from laminar to turbulent flow in some limited area in the radial direction where pressure recovery in relatively large.