Effect of Pressure Difference across Bearing on Characteristics of Cryogenic Hydrostatic Journal Bearing

The effect of the pressure difference across a bearing on the characteristics of the cryogenic hydrostatic journal bearing used in the liquid fuel turbopump of rocket engines in space transport systems is numerically analyzed. The bearing has many recesses arranged in two rows in a staggered manner. The turbulent lubrication equation is solved under the assumptions that the lubricant is liquid nitrogen and that the temperature change in the bearing is negligible which is in accordance with the experimental results. The effects of rotational speed and the pressure drop at the recess edge are considered in the analysis. Variations in the recess pressure, lubricant flow rate, stiffness coefficients, damping coefficients and whirl frequency ratio with the pressure difference across the bearing and the rotational speed are clarified.