CE 704 · Chapter 7
Hydropower Engineering past question
7.1.3 Selection of turbines and their specific speed, Turbine setting
Determine the overall efficiency of a Francis turbine developing 32 MW of power under a net head of 54 m. It is provided with a draft tube, which has an inlet diameter of 3 m and is set 2.2 m above the tailrace level. A vacuum gauge connected to the draft tube indicates a reading of 4.8 m of water. Assume the efficiency of the draft tube is 78%. [5]