Abstract
In this paper, we study the stability of the nonlinear rotor-seal system using Liapunov's first method. The mathematical solutions using multiple scales up to and including second order approximations is investigated. We extract all resonance cases from analytical solution and investigated. It is quite clear that some of the simultaneous resonance cases are undesirable in the design of such system as they represent some of the worst behavior of the system. The effects of various parameters on the behavior of the system and stability of the system are investigated numerically by response curve. Poincare maps are used to determine stability and plot bifurcation diagrams.