A centrifugal fan is balanced by placing a 7 g weight at a radius of 250 mm. The original vibration amplitude was 11.5 m

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A centrifugal fan is balanced by placing a 7 g weight at a
radius of 250 mm. The original vibration amplitude was 11.5 mm/s,
and after adding the balancing weight, the vibration is 0.8 mm/s.
The speed of the fan is 1600 rpm and the weight of the fan is 7
kg.
What will happen if the fan speed is decreased to 1300 rpm?
A centrifugal fan is balanced by placing a 7 g weight at a
radius of 250 mm. The original vibration amplitude was 11.5 mm/s,
and after adding the balancing weight, the vibration is 0.8 mm/s.
The speed of the fan is 1600 rpm and the weight of the fan is 7 kg.
a)Calculate: i.The residual unbalance (2 marks) ii.The eccentricity
(2 marks) iii.The balancing quality grade according to the ISO
balancing standard. (2 marks) b)The stiffness of the fan’s shaft is
85 kN/m. Calculate the natural frequency for the fan on the shaft
(ignore the weight of the shaft). (2 marks) What will happen if the
fan speed is decreased to 1300 rpm?