反向旋转双转子系统滞后特性分析

A counter-rotating dual-rotor system's hysteretic characteristics

建立了考虑中介轴承非线性力的简化双转子模型,应用Matlab进行了数值计算,发现系统升、降速幅频曲线存在明显的滞后跳跃现象,并且在相同参数条件下,高、低压转子的滞后特性相似。进一步分别研究了转速比,中介轴承的径向间隙以及阻尼比对系统滞后特性的影响。研究发现转速比绝对值的增大使跳跃幅度逐渐增大但滞后区大小只有微弱的减小,并且使系统的临界转速逐渐减小,滞后区向左移动;径向间隙的增大使系统的滞后区逐渐增大但跳跃幅度几乎不变,而且对系统临界转速的影响较小;阻尼比的增大使系统的滞后区和跳跃幅度逐渐减小,并且使系统的临界转速减小,滞后区向左移动。该研究结果有助于进一步认识中介轴承对双转子系统振动特性的影响。

A dynamic model of a dual-rotor system with nonlinear force of intermediary bearings was built,and Matlab was used for the numerical calculation. It was shown that there are obvious hysteretic jumping phenomena in the amplitude-frequency curves of the system＇s speed-up and speed-down; the hysteretic characteristics of the high pressure rotor are similar to those of the low pressure rotor under the same parameters. Furthermore,the influences of speed ratio of high pressure rotor to low pressure one,intermediary bearing＇s radial clearance and damping ratio on the system＇s hysteretic characteristics were studied,respectively. The results showed that the increase in speed ratio causes a larger jump but the hysteretic region shrinks slightly and the critical speed decreases,the hysteretic region moves to the left; the larger the intermediary bearing＇s radial clearance,the wider the hysteretic region,but the jump amplitude almost unchanges,and its effect on the critical speed is very small; the larger the damping ratio,the smaller the system＇s hysteretic region,the jump amplitude and the critical speed,the hysteretic region moves to the left. The study results were helpful to a further understanding the effect of intermediary bearings on the vibration features of dual-rotor systems.