On the stability margin of hole-entry hybrid journal bearings considering viscosity-temperature variation

The present study describes the theoretical investigation into the stability margin of a constant flow valve compensated hole-entry hybrid journal bearing system considering the variation of viscosity due to temperature rise of the lubricant. The journal temperature is computed on the basis of average fluid-film temperature. The relevant governing equations are solved using a finite element method and a suitable iterative technique. The thermohydrostatic performance of symmetric and asymmetric hole-entry hybrid journal bearing configurations are studied. The results presented in the study indicate that the variation of viscosity due to temperature rise of the lubricant fluid-film affects the performance of hole-entry hybrid journal bearing system quite significantly.