On the linear stability analysis of journal bearings - Consideration of coupled effects of anisotropic slip and surface roughness

An average modified Reynolds equation (AMRE), considering the coupled effects of anisotropic slip and roughness, is linearized at the operation point to obtain the static and dynamic AMREs. The bearing is modelled as a spring-damper with the dynamic coefficients. The stability analysis of the rigid rotor/bearing system showed that slip length B has negative effects on load capacity W and critical mass M-cr. Slenderness ratio progressively strengthens the negative effects of B on M-cr for circumferential-slip, yet weakens those negative effects for axial slip. For short and square bearings, W and M-cr for Peklenik number gamma = 9 are greater than those for gamma = 1, followed by gamma = 1/9; for long bearings, W and M-cr for gamma = 1/9 are greater than those for gamma = 1, followed by gamma = 9.