Question

1.       A centrifugal pump running at 2950 rpm under test at peak efficiency gave the following results: Effective head H= 75m of water, rate of flow Q= 0.05 m³/s, overall efficiency h= 76%.

A dynamically similar pump is to operate at a corresponding point of its characteristic when delivering 0.5 m³/s through a pipe 800m long and 1m diameter for which the friction coefficient f =0.05. The pipe discharges 90m above reservoir level. Determine the rotational speed at which the pump should run to meet the duty and ratio of its impeller diameter to that of the pump mentioned above. What will be the power consumed by the pump.

Answer 1