Abstract：Crack fault is an often occurred complex high-dimensional nonlinear problem in large rotating machinery system. In this paper, a low-pressure rotor system of an aero engine with a pair of liquid film lubricated bearings is modeled into a twenty-two degree of freedom nonlinear system using Lagrange method. This high dimensional nonlinear system can be reduced into a two degree of freedom system preserving the crack fault oil-film oscillation property by introducing the modified POD method. Numerical simulations demonstrated the efficiency of the method is shown by comparison with the computed results given for both the original and the reduced systems. C-L method is also employed to obtain the dynamical behaviours of the reduced system, which reflect the natural property of the crack fault.
2014, Vol. 33 
