To meet the advanced bearings needs of cryogenic rocket engine turbopumps, a hybrid bearing is designed. A mathematical model concerning turbulent-state Reynolds Equations has been presented and solved using the finite difference method (FDM). The static and dynamic characteristics of hybrid journal bearings handling low viscosity water lubricated under extreme conditions of high-pressure and high-DN (diameter x running speed) have been studied. The results of numerical predictions show that either increasing supply pressure of lubrication or putting bearing working in a narrower radius clearance is an efficient way to increase hybrid bearing's load capacity and stiffness. Furthermore, the lower eccentricity ratio ( epsilon < 0.5) has little effect on the stiffness of bearing. Comparisons are presented between measurements and predictions for a 30 mm diameter, high-speed (20000 rpm), high-pressure (7 MPa), hybrid bearings using water (30 degrees C) as a test fluid. These findings provide the theoretical reference for the design of cryogenic hybrid bearings applied in the Liquid Rocket Engine Turbopumps.
