Static and Dynamic Performance of Externally Pressurized Fluid Film Journal Bearings in the Turbulent Regime

Abstract

The fluid film lubrication equations for externally pressurized bearings are solved for steady-state performance and spring and damping coefficients using finite differences and a variable grid bearing model. Turbulence is included as local effective viscosities. Entrance inertia effects are included at the recess edges and are seen to be a significant factor for flow estimates. Performance data is developed for a six-pocket bearing of L/D = 0.75. Experimental verification was obtained for load capacity, flow, and dynamic coefficients, using a two-bearing dynamic test rig and water at speeds from 0 to 4000 rpm. Axial flow of Reynolds numbers range from 22,000 to 125,000.