Determine algebraic equations for the pump head rise, power, and efficiency as functions of flow rate based on the data from Problem 12.18. Analytically determine the Best Efficiency Point and the BEP flow, head rise, and power. How do these values compare with those from Problem 12.18?

Problem 12.18

The centrifugal pump shown in Fig. P12.18 is not selfpriming. That is, if the water is drained from the pump and pipe as shown in Fig. P12.18(a), the pump will not draw the water into the pump and start pumping when the pump is turned on. However, if the pump is primed [i.e., filled with water as in Fig. P12.18(b)], the pump does start pumping water when turned on. Explain this behavior.

Figure P12.18

Transcribed Image Text:

Pump Pump (a) (b)