Internal combustion engines
The engine power that actually reaches the output shaft or flywheel of an engine is known as the brake power. It is the power that is measured by a dynamometer and a dynamometer is also known as a brake, hence the term, brake power. Hydraulic dynamometers of the type manufactured by the Heenan Froude Company are commonly used for engine testing purposes. The energy from the engine is converted into heat by the action of the dynamometer rotors and the action is somewhat similar to the action of a torque convertor. Electrical dynamometers are used for high-speed engine testing; these convert the engine power into electricity which is then dissipated through heat or electro-chemical action. Indicated power is the power that is developed inside the engine cylinders. It is determined by measuring the pressures inside the cylinders while the engine is on test, on a dynamometer.