What is Rotordynamic analysis?

What is Rotordynamic analysis?

Lateral Analysis (also called Rotordynamics Analysis) simulates the rotating system, calculates the critical speeds, predicts vibration amplitudes, and provides recommendations to reduce vibration risks.

What do you mean by critical speed?

Critical speed (nk) is the rotational speed at which acting dynamic forces cause a machine component (e. g. shaft, rotor) to vibrate at its natural frequency (also referred to as intrinsic frequency, fi) and can even result in resonant vibrations throughout the entire machine and pump set.

What is forward whirl and backward whirl?

The damped natural frequency is usually referred to as whirl speed. At zero shaft speed, the forward and backward frequencies are identical (repeated eigenvalues). As the speed increases, each vibration mode is split into two modes known as forward and backward precessional modes due to the gyroscopic effect.

What is jeffcott rotor model?

Jeffcott rotor. The simplest model that can be used to study the flexural behavior of rotors consists of a point mass attached to a massless shaft.

What is whirling in vibration?

When the. shaft rotates at a speed equal to the natural frequency of. transverse oscillations, this vibration becomes large and. shows up as a whirling of the shaft. It also occurs at multiples.

What is meant lateral vibration?

A vibration in a helicopter in which the rotor moves back and forth in a lateral plane, or side-to-side direction.

What is whirling or critical speed?

Critical or whirling or whipping speed is the speed at which the shaft tends to vibrate violently in the transverse direction. The eccentricity of the C.G of the rotating masses from the axis of rotation of the shaft.

What is critical resistance and critical speed?

Answer:Critical Field Resistance: It is that value of the field resistance at which the D.C. shunt generator will fail to excite. Critical Speed: It is that speed for which the given shunt field resistance becomes the critical field resistance.

What is backward whirling?

Another cause of split resonance and backward whirl is gyroscopic forces generated by disks, especially over-hung ones. It is also possible for backward whirl to occur at a shaft natural frequency due to an instability mechanism. This generally occurs at sub-synchronous speeds.

What is whirl speed?

Whirling speed or Critical speed of a shaft is defined as the speed at which a rotating shaft will tend to vibrate violently in the transverse direction if the shaft rotates in the horizontal direction. In other words, the whirling or critical speed is the speed at which resonance occurs.

What is synchronous vibration?

Any vibration that occurs at the 1X frequency, or a whole number multiple of it is referred to as a synchronous vibration. Any vibration that is greater than the 1X frequency, but is not a whole number multiple of it is called a non-synchronous vibration.

What is meant by torsional vibration?

Torsional vibration is angular vibration of an object—commonly a shaft along its axis of rotation. Also, the components transmitting the torque can generate non-smooth or alternating torques (e.g., elastic drive belts, worn gears, misaligned shafts).