THERMAL EFFECTS IN LIQUID-OXYGEN HYDROSTATIC JOURNAL BEARINGS

Numerical predictions for static performance and rotordynamic coeffici ents for a roughened stator LO(2) HJB operating at typical conditions in the SSME HPOTP are presented. The calculations are performed for an adiabatic THD model and an isothermal flow model. The two flow models predict almost identical static and dynamic performance characteristi cs, even though large temperature increases and fluid property variati ons in the bearing fluid film are predicted by the THD model. However, a high temperature rise across the bearing affects not only the liqui d properties but also the bearing geometry. A parametric study shows a strong impact of bearing clearance variations on the bearing performa nce and, hence, the importance of thermal effects becomes evident.