Numerical and Experimental Analysis of a Shaft Bow Influence on a Rotor to Stator Contact Dynamics

The shaft bow problem presents a real situation especially in case of slender rotors. This paper investigates the shaft bow influence on the rotor-stator contact dynamics. For this purpose the rotor is described as a simple Jeffcott model and the stator as an elastically suspended rigid ring. To test the numerical model, except a usual run down analysis, an emergency shut down after the sudden rotor unbalance increase is also analyzed. Numerical integration is carried out by the fourth-order Runge-Kutta method. Two different normal force models for the rotor-stator interaction are analyzed. For analyzed parameters, both linear and nonlinear (Hunt and Crossley), normal force models gave similar rotor and stator responses. To confirm some of the results and to tune the numerical model, the experimental investigation on the test rig was conducted. (C) 2008 Journal of Mechanical Engineering. All rights reserved.