The power specific speed of a 4 MW Francis turbine is 0.8, and the hydraulic efficiency can be assumed to be 90%. The head of water supplied to the turbine is 100 m. The runner vanes are radial at inlet and their internal diameter is three-quarters of the external diameter. The
meridional velocities at runner inlet and outlet are equal to 25% and 30%, respectively, of the spouting velocity. Determine
a. the rotational speed and diameter of the runner;
b. the flow angles at outlet from the guide vanes and at runner exit;
c. the widths of the runner at inlet and at exit. Blade thickness effects can be neglected