Abstract：With an aim to accurately reflect the motion characteristics of the steam turbine rotor-bearing-seal system under steam exciting force, the differential equation of rotor motion including nonlinear dynamic characteristic (nonlinear stiffness, damping) is derived. The simulative equation of nonlinear steam flow excitation force obtained by numerical simulation is coupled to the equation of motion, and the corresponding equation of motion is solved by Runge-Kutta method. The necessity of investigating nonlinear factors and the accuracy of motion differential equation are verified based on experimental comparison. On this basis, the influence of different nonlinear dynamic characteristic coefficients on the motion characteristics and stability of the rotor under the steam flow excitation force is analyzed. It is shown from the result that the nonlinear dynamic characteristic in the system will change the different types of chaotic motion regions and the displacement of the rotors, making the occurrence range and amplitude of the power frequency of 1/2, 1/3, and 2/3 change, and the dense frequency phenomenon increase. The rotor displacement in the high load area decreases after coupled thermal and dynamic loads. Compared with the Lyapunov exponent, the mean value increases after considering nonlinear dynamic characteristic; reasonable nonlinear stiffness can improve the stability of the system, and high nonlinear damping can improve the stability of the system; the system with coupled thermal and dynamic loads is more stable during operation under high load.
曹丽华，薛川，司和勇，高路路，李想，郝德成. 非线性动态特性系数对汽轮机转子-轴承-密封系统运动特性的影响[J]. 振动与冲击, 2024, 43(1): 172-183.
CAO Lihua, XUE Chuan, SI Heyong, GAO Lulu, LI Xiang, HAO Decheng. Effects of nonlinear dynamic characteristic coefficients on motion characteristics of a steam turbine rotor-bearing-seal system. JOURNAL OF VIBRATION AND SHOCK, 2024, 43(1): 172-183.
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