Hydraulic Dynamometer

Hydraulic Dynamometer:

A hydraulic dynamometer as shown in the figure below works on the principle of dissipating the power in fluid friction rather than in dry friction.

In principle, hydraulic dynamometer construction is similar to that of a fluid flywheel.

Hydraulic dynamometer consists of an impeller or inner rotating member coupled to the output shaft of the engine.

The impeller in this dynamometer rotates in a casing filled with a fluid.

Due to the centrifugal force developed in the outer casing, tends to revolve with the impeller, but is resisted by a torque arm supporting the balance weight.

The frictional forces generated between the impeller and the fluid are measured by the spring balance fitted on the casing.

The heat developed due to the dissipation of power in Hydraulic dynamometer is carried away by a continuous supply of the working fluid.

The output power can be controlled by regulating the sluice gates which can be moved in and out to partially or wholly obstruct the flow of water between the casing and the impeller.