Question

A centrifugal pump at its best point of efficiency discharges \(0.04 \, \text{m}^3/\text{sec}\) against a total head of \(42 \, \text{m}\). When the speed of pump is \(1370 \, \text{rpm}\), compute the specific speed of the pump.

• A. \(6.52\)
• B. \(18.90\)
• C. \(181.86\)
• D. \(16.60\)

Hint:

Specific speed formula for centrifugal pump: \[ \boxed{ N_s = \frac{N\sqrt{Q}}{H^{3/4}} } \] where:
• \(N\) = rpm
• \(Q\) = discharge
• \(H\) = head Pump classification based on specific speed:
• Low \(N_s\) \(\rightarrow\) Radial flow pump
• Medium \(N_s\) \(\rightarrow\) Mixed flow pump
• High \(N_s\) \(\rightarrow\) Axial flow pump

Answer 1

The Correct Option is B