Effect of Recess Configurations on the Static Load Performance of a Hydrostatic Journal Bearing

Abstract

Hydrostatic journal bearings (HJBs) are commonly utilized in cryogenic turbomachinery due to their high radial stiffness, long life-span, and low friction and wear. The load carrying capacity and static stiffness of HJBs are enhanced by the presence of a recess. Extensive research has been conducted to investigate the effect of different recess shapes, see Refs. [1-8]. In this study, we present numerical predictions of the static load performance of HJBs using various cryogenic fluids, including LCH₄, LH₂, LO₂, LN₂, and air as lubricants. We consider different operating conditions, lubricants, and recess shapes to evaluate the effect of fluid properties on the static load performance. The supply pressures of fluid through the orifice range from 40 bar(g) to 70 bar(g). The governing equation of the predicted model for the thin fluid film is the turbulence Reynolds equation. The predicted results show that the recess configurations affect the static load performance of HJBs. However, the effects of the recess configurations are insensitive under certain operating conditions. The work indicates that the recess configurations are critical in predicting the HJB’s performance, such as recess pressure, flow rate, stiffness, and damping. Therefore, selecting an appropriate recess configuration is essential for optimizing design and enhancing the static load performance of HJBs.