Catastrophe Performance Analysis of Aerodynamic Excitation for Steam Turbine

Catastrophe fault caused by aerodynamic excitation is a kind of frequency fault for steam turbine, which brings great destructive and dangerous because of its external form of unexpected features. Based on the nonlinear vibration theory and catastrophe theory, harmonic balance method is used to derive the frequency-response equation of nonlinear rotor´s aerodynamic excitation, and cusp catastrophe and bifurcation set of aerodynamic excitation are established. Then, catastrophe impact factors are identified, and catastrophe performance development laws of aerodynamic excitation are analyzed and system´s catastrophe regions are divided. Results of this study provide a new way for the catastrophe fault caused by aerodynamic excitation to descript and prevent for steam turbine.