Definition

Noun: A type of propulsion device consisting of a central hub with several angled blades (typically three or more) radiating from it. The entire assembly rotates on a shaft, and its helical (screw-like) motion pushes against a fluid—most commonly water or air—to generate thrust and propel a vehicle forward.

Usage

The term "screw propeller" specifically describes the mechanical device itself. It is a technical term commonly used in marine and aeronautical engineering contexts. - It is used to describe the primary propulsion system for most ships and boats. - It can also refer to similar devices used in aircraft (propellers) or certain types of fans.

Examples

• The ship's screw propeller was damaged after hitting a submerged log.
• Early aviation pioneers experimented with different designs for the screw propeller to achieve greater efficiency.
• The efficiency of a screw propeller depends on the pitch and shape of its blades.

Advanced Usage

• "Twin-screw propeller": A propulsion setup for a vessel using two independent propellers on separate shafts, typically for improved maneuverability.
  • The large ferry was equipped with a twin-screw propeller system.
• The concept is fundamental to propeller theory, which analyzes the fluid dynamics of how a rotating screw generates thrust.

Variants and Related Words

• Propeller (n): A more common and general term for a device with rotating blades that creates thrust. "Screw propeller" is a specific type of propeller.
• Prop (n): An informal shortening of "propeller."
• Screw (n): In nautical contexts, "screw" is often used alone as a synonym for a ship's propeller (e.g., "the ship's screw").
• Rotor (n): While a rotor also has rotating blades, it typically refers to the lifting device of a helicopter or the rotating part of a turbine, not usually a direct synonym for propulsion.

Synonyms

• Propeller
• Marine propeller (when specifying use in water)
• Aircrew (archaic or very specific term for an aircraft propeller)

Related Phrases

• Feathering the propeller: An action on some aircraft to rotate the propeller blades to a minimal drag position, often when an engine fails.
• Variable-pitch propeller: A propeller where the angle (pitch) of the blades can be adjusted during operation for optimal performance at different speeds.

Noun

1. a propeller with several angled blades that rotates to push against water or air