Francis Turbine Runner Blade Hydraulics

A Francis turbine converts falling water into shaft power by steering it through a ring of guide vanes and then through a spinning runner whose curved blades change the water's momentum. This simulator builds a 3D spiral casing, guide-vane ring and 13-blade runner over a draft tube, and drives the classic velocity-triangle analysis behind it: the guide vanes set the absolute velocity C, the runner rim carries it at blade speed U, and the vector difference is the relative velocity W the blade must actually be curved to follow. Adjust the guide-vane angle, runner speed and net head to watch Euler's turbine equation, hydraulic efficiency and the runner's shockless-entry condition play out live — including the incidence-angle mismatch that appears whenever the machine runs off its design point.