If γ is assumed as 9.81 kN/m^3.
(For any other specific weight γ’ , multiply 928,200 by(γ’/γ.) Then, by employing values of ⏀_e and B/D from Fig.
16.16 a value of ηC_r may be obtained for any specific speed.
It is seen that in any given case the value of C_r depends upon the turbine efficiency.
The value of the efficiency