Answer:
number of stages for the pump is 4
Explanation:
given data
water head Hm = 50 m
flow rate r = 0.1 m³/s
rotating N = 1800 rpm
to find out
optimal number of stages for the pump.
solution
we consider here specific speed does not exceed more than 82
so Ns formula will be
Ns = [tex]\frac{N\sqrt{r} }{H^{3/4}}[/tex]
here Ns id 82 and N is rotating and r is flow rate
so
82 = [tex]\frac{1800\sqrt{0.1} }{H^{3/4}}[/tex]
so H = 13.23 m
so
number of stage n is
nH = Hm
n = [tex]\frac{50}{13.23}[/tex]
n = 3.77 ≈ 4
so number of stages for the pump is 4