Abstract
This research aims to study a numerical analysis to investigate the dynamic orbits of a rotor supported by two turbulent journal bearings considering longitudinal and transverse roughness effect under nonlinear suspension. The dynamic response of the rotor center and bearing center are studied. The dynamic trajectories of the rotor center and bearing center, Poincaré maps, bifurcation diagrams and the maximum Lyapunov exponent method are employed to analyze dynamic responses in this study. The results show that either the longitudinal and transverse or the values of roughness parameters c1 would not affect strongly nonlinear rotor-bearing system very much but the difference of dynamic response between considering with roughness effect and without roughness effect are very obvious. The modeling results provide some theoretical references for further researching of rotor-bearing system for rotating machinery that operate in highly rotational speed, especially it considers roughness effect, turbulent flow and nonlinear suspension of bearing system.