The specific speed (Ns) of a pump is given by :
1
\({N_s} = \frac{{N\sqrt Q }}{{H_m^{\frac{5}{4}}}}\)
2
\({N_s} = \frac{{N\sqrt P }}{{H_m^{\frac{3}{4}}}}\)
3
\({N_s} = \frac{{N\sqrt Q }}{{H_m^{\frac{3}{4}}}}\)
4
\({N_s} = \frac{{N\sqrt P }}{{H_m^{\frac{5}{4}}}}\)