Water brake

As the turbine or propeller turns, mechanical energy is transferred to the water due to turbulence and friction.

Almost all of the horsepower of the system turning the rotor (usually an internal combustion engine) is converted into a temperature change of the water.

Therefore, water must constantly move through the device at a rate proportional to the horse power that is being absorbed.

The water enters in the center of the device and after passing through the pockets in the stator and rotor exits the outside of the housing through a controlled orifice.

Water brakes are commonly used on some forms of dynamometer but have also been used on railways vehicles such as the British Advanced Passenger Train.