The Francis turbine is a type of water turbine that was developed by James B. Francis in Lowell, Massachusetts. It is an inward-flow reaction turbine that combines radial and axial flow concepts.
All the parts of this turbine including the spiral casing, the guide (stay) vanes, runner blades and the draft tube are clearly visible in this model.
Here water enters horizontally in a spiral shaped pipe (spiral case) wrapped around the outside of the turbine's rotating runner and exits vertically down through the center of the turbine.
With this model, students can appreciate the working of the turbine, in which the working fluid comes to the turbine under immense pressure and a part of this fluid’s energy is extracted by the turbine blades, while the remaining part of the energy is extracted by the volute casing of the turbine. At the exit, the turbine’s tube is shaped to help decelerate the water flow, so that water leaves with very little kinetic or potential energy.