10

m3/s

4000 gpm

The shut-off power is 34 hp (25 kW), arising from a power coefficient of 0.047 from Mockridge's correlation36 for a b2/D2 of 1.59/12 (= 40.4/304.8) = 0.1325—as found from Figure 23. This is 44% of the design-point power, a typical result. As seen in Section 2.3.1, this percentage increases with specific speed, where, of course, b2/D2 is also larger36.

The NPSHR (= NPSH3% for this example) at off-design conditions is estimated empirically. At the higher, non-recirculating flow rates, NPSHR is related to the head required to accelerate the relative velocity within the blades to values higher than at the design point14. As stated in Section 2.3.1, operation at NPSH3% involves performance in the presence of extensive internal two-phase behavior. This is complicated by recirculation at the lower flow rates. Therefore, the full NPSHR curve in such a case usually has to be established experimentally.

Survival Treasure

Survival Treasure

This is a collection of 3 guides all about survival. Within this collection you find the following titles: Outdoor Survival Skills, Survival Basics and The Wilderness Survival Guide.

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