Sin γ = ui / vi = 0.125 / 0.721 = 0.173;
γ = 10° nearly.
Tangential Velocity of Water entering Wheel.
wi = vi cos γ = 0.7101 √2gH.
Angle of Vanes at Inlet Surface.
Cot θ = (wi − Vi) / ui = (.7101 − .66) / .125 = .4008;
θ = 68° nearly.
Hydraulic Efficiency of Wheel.
| η = wiVi / gH = .7101 × .66 × 2 = 0.9373. |
This, however, neglects the friction of wheel covers and leakage. The efficiency from experiment has been found to be 0.75 to 0.80.