Pressure Boundary Conditions of High-Speed Thrust Bearings

Abstract

This paper describes a study on the boundary conditions at the inlet edge of high-speed thrust bearings in a turbulent flow regime, taking into account the inertia effects. The basic lubrication equations in terms of pressure and stream function are solved for finite-width bearings by applying a numerical calculation technique combining control volume integration and Newton-Raphson linearization method. Moreover, an analytical solution is given for infinitely long bearings. Static bearing performance characteristics such as pressure distribution, load-carrying capacity, pressure center and inlet flow rate are calculated for three kinds of inlet boundary conditions in relation to three types of lubrication conditions, namely: the flooded condition, the overflooded condition and the starved condition. Some samples of the numerical results are presented in graphic form, and the relationship between the inlet boundary conditions and static bearing performance is discussed.