Definition

Noun: A type of turbine where the rotor is driven by high-velocity jets of fluid (such as water or steam) that impinge directly upon the blades. The fluid transfers its kinetic energy to the blades without a significant pressure drop occurring within the turbine casing itself.

Usage

The term "impulse turbine" is used to describe a specific class of turbine machinery, primarily in engineering, physics, and energy generation contexts. It contrasts with a "reaction turbine," where the rotor is driven by a combination of pressure and velocity changes.

Examples

• The impulse turbine is highly efficient for applications with high head and low flow rate, such as in Pelton wheel designs.
• In a simple steam impulse turbine, expanding steam is directed through nozzles to form high-speed jets that strike the rotor blades.
• The design principle of the impulse turbine involves converting the fluid's pressure into velocity in a nozzle before it contacts the blades.

Advanced Usage

• "pure impulse turbine": Often used to emphasize that the turbine operates entirely on the impulse principle, with no reaction component in the blade passages.
• In technical discussions, the efficiency and design of an impulse turbine are frequently analyzed using velocity diagrams to understand the fluid's momentum transfer.

Variants and Related Words

• Impulse stage (noun): A single set of nozzles and moving blades in a turbine where energy transfer occurs primarily via impulse.
• Impulse blade (noun): A blade designed specifically to efficiently capture the kinetic energy from a fluid jet in an impulse turbine.

Synonyms

• Velocity turbine: A less common synonym highlighting that the turbine is driven by fluid velocity.
• Jet turbine: A descriptive synonym focusing on the jet mechanism.

Related Concepts (Not Synonyms)

• Reaction turbine (noun): The primary contrasting turbine type, where the rotor is driven by the fluid's reaction force as it accelerates through the blade passages.
• Pelton wheel (noun): A common and classic type of impulse turbine used for hydropower.
• De Laval turbine (noun): An early type of impulse steam turbine.

Noun

1. a turbine that is driven by jets direct against the blades