Torsional vibration absorber using liquid

在旋转机械中，通常发现激励转矩以与转速相同的频率或以转速的倍数发生。一种未调谐的减振器，如经常用于减少扭转振动的兰开斯特。然而，它不如动力吸振器有效。如果附加的动力吸振器具有与激励频率相同的固有频率，则振动被抑制。离心摆吸振器如果调谐良好，可有效地消除扭转振动。然而，它有时不令人满意的操作，由于摩擦或调整不足。一个实验和理论研究进行抑制转子的扭转振动，附加一个空心圆柱部分充满液体。空心圆柱体被径向壁分成相同的扇区。除了测量扭转振动外，还拍摄表面波以观察所含液体的运动。测试的空心圆柱体的分割数为2、3、4、6和8。填充比的调谐条件也进行了检查。实验结果表明，表面波向后移动，即沿与旋转方向相反的方向传播。包括科里奥利加速度项的分析。分析结果与实验结果吻合良好，而没有科里奥利项的分析显示出较差的一致性。因此，由于在液体移动时作用的科里奥利力，表面波运动不是静止的。

In rotating machinery, it is generally found that exciting torque occurs at the same frequency as the rotating speed or at multiples of the rotating speed. An untuned vibration damper, such as the Lancaster damper.is frequently used to reduce torsional vibrations. However, it is not as effective as a dynamic absorber. If an attached dynamic absorber has the same natural frequency as the exciting frequency, vibration is suppressed. A centrifugal pendulum vibration absorber effectively eliminates torsional vibrations if it is well tuned. However, it sometimes does not operate satisfactorily due to friction or insufficient adjustment.An The experimental and theoretical study is performed on suppression of torsional vibrations of a rotor by attaching a hollow cylinder partially filled with liquid. The hollow cylinder is divided into identical sectors by radial walls. In addition to measuring torsional vibration, surface waves were photographed to observe the motion of the contained liquid. The number of divisions of tested hollow cylinders is 2,3,4,6, and 8. The tuning conditions for fill ratios are also examined. Experimental results show that the surface waves move backward that is travel in the direction opposite the rotation. Analysis including the Coriolis acceleration terms is presented. Analytical results show good agreement with the experimental ones whereas the analysis without Coriolis terms shows poor agreement. Accordingly the surface wave motion is not stationary due to the Coriolis force which acts while the liquid moves.