Which of the following can lead to an increase in amplitude at the pump vane rate frequency?

The selection of "all of the above" as the answer is grounded in the understanding that each of the listed factors can contribute to an increase in amplitude at the pump vane rate frequency, thus collectively reinforcing that answer.

Non-uniform variable pitch blades can cause mismatches in hydrodynamic forces acting on the blades, which may lead to vibrations. As these blades interact with the fluid, any deviation from expected performance can produce fluctuating forces, contributing to increased amplitude at the vane rate frequency.

Blade or vane wear, whether from abrasion or cavitation, can compromise the structural integrity and hydrodynamic efficiency of the pump. As the blades wear down, changes in their shape and surface characteristics can lead to imbalanced forces, which may exacerbate vibration levels. This wear can cause resonance phenomena, resulting in an increased amplitude at certain frequencies.

Improper performance parameters encompass a range of operational issues, such as incorrect flow rates or pressures, that can disrupt the intended functioning of the pump. When the pump operates outside its optimal conditions, it can produce unsteady flows or vibrations at specific frequencies, including the vane rate frequency, leading to increased amplitude.

Each of these factors demonstrates a direct or indirect influence on the vibration characteristics of the pump, signifying that all