微型燃气轮机浮环轴承-悬臂转子系统动力学特性分析

Rotordynamic analysis of a micro gas turbine overhung rotor system supported on floating ring bearing

对浮环轴承支承的悬臂转子系统的动力学特性进行分析,建立了浮环轴承双层油膜Reynolds方程和浮环运动方程。采用4节点等参h-精细有限元网格,通过Galerkin方法求解系统Reynolds方程得到双层油膜压力。在小摄动范围内,联合悬臂转子系统的动力学方程、浮环运动方程求出浮环轴承的等效刚度和阻尼系数。应用商业有限元软件ANSYS12.1对实际微型燃气轮机用浮环轴承-悬臂转子系统进行临界转速、谐响应及不平衡响应等转子动力学仿真计算。通过与实验结果对比,验证了此物理计算模型的正确性,并证明了用此方法分析浮环轴承-悬臂转子转子动力学问题具有实际意义。

The rotor dynamic performance of an overhung rotor supported on floating ring bearings（FRBs） was analysed.The Reynolds equation and bushing motive regulation of FRB were established.The forces of two oil films were calculated by using 4-node isoperimetric h-version refining FEA method linking with Galerkin approximation.The equivalent stiffness and damping coefficients of the FRB were obtained combining and solving the dynamic equations.Rotodynamic simulations were carried out to discuss the critical speed and unbalance response by using the commercial software Ansys 12.1.As compared with test results,the proposed model of overhung rotor system is of good validity and practicability in design.