What does the term impulse turbine refer to?

The term impulse turbine specifically refers to a type of turbine where high-pressure steam expands and converts its potential energy into kinetic energy as it passes through nozzles. This steam then impinges directly on the rotor blades, creating a force that drives the rotor, resulting in mechanical energy production. The key aspect of impulse turbines is that the pressure drop occurs in the nozzles rather than across the blades themselves. This design allows for the conversion of steam energy into mechanical work effectively, making the direct impact on the rotor blades a defining characteristic of impulse turbines.

In contrast, turbines that operate primarily on pressure differences typically rely on consistent pressure drops across the turbine, which does not align with the impulse concept. Centrifugal force turbines, meanwhile, utilize rotational motion to generate energy rather than relying on direct impact from steam or fluid. Lastly, turbines designed for maximum efficiency at low speeds might fall under different categories of turbine design that focus on efficiency rather than the impulse mechanism, which is optimized for higher velocity inputs and impacts.