Linear and Nonlinear Performance Analysis of Hydrodynamic Journal Bearings with Different Geometries

In rotor dynamics, a traditional way of representing the dynamics hydrodynamic bearings is using stiffness/damping coefficients. It thus necessary to carry out linearization forces around shaft’s equilibrium position. However, have highly nonlinear nature, depending on operating conditions. Therefore, this paper discusses applicability these linear/nonlinear approaches computational model rotating system, where finite element method used for modelling and volume bearing calculation. The main goal investigate boundaries linear approximation present in lobed bearings, with system under high loading Several numerical simulations were performed varying preload parameter speed. A comparison system’s responses, time domain (shaft orbits) frequency (full spectrum), made models. Results showed that trilobed are more susceptible nonlinearities, even situations smaller vibration amplitudes, while elliptical sensitive only larger amplitudes. These analyses great importance mapping influence nonlinearities different types fixed geometry, verify dynamic response. This study important serves as basis cases monitoring fault diagnosis (in field structural health monitoring) since it crucial distinguish what would be signature or standard effect created by use bearings.