In a gearing system, pump speed is one third of the motor. Shaft from motor is 6 cm in diameter and 30cm long, the impellar shaft is 10cm diameter and 60cm long. Mass moment of inertia is 1500 Kg-m2, C = 80Gn/m2. Neglecting the inertia of shaft and gears calculate the frequency of free torsional vibrations in Hz.

Torsional Vibrations topics include: Torsional vibrations of single, two and three rotor systems, torsionally equivalent shaft, isolation and transmissibility and geared system torsinal vibrations. Torsional vibration is a type of vibration that involves the angular vibration of an object, usually a shaft, along its axis of rotation. It can be caused by time-alternating torques that are superimposed on the steady running speed of a rotating shaft.  Torsional vibration can be measured by measuring the RPM of a shaft with a high number of pulses per revolution (PPR).  It can be measured... Show more

Torsional Vibrations topics include: Torsional vibrations of single, two and three rotor systems, torsionally equivalent shaft, isolation and transmissibility and geared system torsinal vibrations.

Torsional vibration is a type of vibration that involves the angular vibration of an object, usually a shaft, along its axis of rotation. It can be caused by time-alternating torques that are superimposed on the steady running speed of a rotating shaft. 

Torsional vibration can be measured by measuring the RPM of a shaft with a high number of pulses per revolution (PPR). 
It can be measured using:
A torsiograph
An encoder
A laser vibrometer
A strobe light
A telemetry system 

Torsional vibration can be controlled by:
Dissipating the torsional vibration (kinetic) energy into heat (thermo-elastic)
Using torsional vibration absorbers 

Torsional vibration is different from lateral vibration, which occurs in the radial direction, and axial vibration, which occurs along the shaft length. 

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