Effect of design parameter variations on hybrid (combination hydrostatic and hydrodynamic) bearings for use in high speed turbomachinery

Abstract

Hybrid (combination hydrostatic and hydrodynamic) bearings have been proposed for use as a support element in cryogenic high speed turbomachinery for primary and auxiliary space power applications because of their long lifetime, low friction and wear, and ability to use low viscosity fluids. However, very little work has been done in determining the rotordynamic performance of hybrid journal bearings. This thesis presents theoretical and experimental results for radial-injection, orifice-compensated, annulus-fed hybrid water journal bearings which show the effects on bearing performance of changing the following design parameters: radial clearance, concentric recess pressure ratio, recess-to-land area ratio, and recess depth geometry. Experimental test results are used to evaluate predictions from the analytical hybrid bearing computer model developed by San Andres (1990).