Research on 1:2 subharmonic resonance and bifurcation of nonlinear rotor-seal system

The 1:2 subharmonic resonance of the labyrinth seals-rotor system is investigated, where the low-frequency vibration of steam turbines can be caused by the gas exciting force. The empirical parameters of gas exciting force of the Muszynska model are obtained by using the results of computational fluid dynamics (CFD). Based on the multiple scale method, the 1:2 subharmonic resonance response of the dynamic system is gained by truncating the system with three orders. The transition sets and the local bifurcations diagrams of the dynamics system are presented by employing the singular theory analysis. Meanwhile, the existence conditions of subharmonic resonance non-zero solutions of the dynamic system are obtained, which provides a new theoretical basis in recognizing and protecting the rotor from the subharmonic resonant failure in the turbine machinery.     

Research on 1∶2 subharmonic resonance and bifurcation of nonlinear rotor-seal system

The 1∶2 subharmonic resonance of the labyrinth seals-rotor system is investigated,where the low-frequency vibration of steam turbines can be caused by the gas exciting force.The empirical parameters of...     

The general solution of bending of a spherical thin shallow shell with a circular hole at the center under arbitrary transverse loads

Basing several suggestions appeared in [1], we find out the general solution of the bending of a spherical thin shallow shell with a circular hole at the center. As we know, very few papers had touched upon these problems.     

非线性转子-密封系统1∶2亚谐共振分岔研究

研究了转子-密封系统在气流激振力作用下的低频振动——1∶2亚谐共振现象．利用流体计算动力学（CFD）方法对转子-密封系统进行了流场模拟计算,辨识出适用于气流流场的Muszynska模型参数,并建立了转子-密封系统动力学方程．采用多尺度方法将系统进行3次截断,并得到系统响应．采用奇异性理论研究了系统的1∶2亚谐共振,进一步得到系统亚谐共振的分岔方程和转迁集,根据转迁集给出了在不同奇异性参数空间内的分岔图．同时,由分岔方程得到了亚谐共振非零解存在的条件．其分析结果对抑制转子-密封系统的亚谐振动有重要的工程意义．