Chapter 14, Problem 85CP

A Francis radial-flow hydroturbine has the following dimensions, where location 2 is the inlet and location 1 is the outlet: $r_2=6.60ft,r_1=4.40ft,b_2=2.60ft$ , and $b_1=7.20ft$ . The runner blade angles are ${\beta }_2=82°$ and ${\beta }_1=46°$ at the turbine inlet and outlet, respectively. The runner rotates at in =120 rpm. The volume flow rate at design conditions is $4.70\times {10}^6$ . Irreversible losses are neglected in this preluminiary analysis. Calculate the angle a₂ through which the wicket gates should turn the flow, where a₂ is measured from the radial direction at the runner inlet (Fig. P14-82). Calculate the swirl angle a₁, where a₁ is measured from the radial direction at the runner outlet (Fig. P14-82). Does this turbine have forward or reverse swirl? Predict the power output (hp) and required net head (ft).