Turbine

A Turbine is an example of Turbomachinery that converts hydraulic energy into mechanical energy by outputting a rotating shaft. The rotating part is called the runner.

Turbine Classification
All turbines exist on a spectrum with reaction on one side and impulse on the other:

https://i.imgur.com/eMa1awD.png

An Impulse turbine is like a water wheel, where the fluid travels perpendicular to the runner and just pushes it along. There is no pressure drop, and the fluid jet transfers kinetic energy to the wheel via momentum transfer. Examples include Pelton and Crossflow.

A reaction turbine is more complex and works by passing the fluid through the turbine like in jet turbine. There is pressure variation across the blades and across the whole turbine, which forces the runner to rotate. Examples include Francis and Kaplan.