propulsor

A propulsor is a device that generates thrust to propel a vehicle, such as a ship or aircraft. This is achieved by imparting motion to a fluid, like water or air. The fundamental principle behind a propulsor's operation is Newton's second law of motion, which states that the force required to accelerate a mass is proportional to the product of that mass and its acceleration.12

There are two main types of propulsors:
* Propellers: These have radiating blades that rotate to push air or water, creating thrust. Examples include airplane propellers and helicopter rotors, often called airscrews in Great Britain.3
* Jet engines: These expel a high-velocity stream of gas to generate thrust. This can involve a turbine driving an external propulsor (like a fan in a turbofan engine) or the direct expulsion of gas from the engine itself (as in a turbojet).24

For efficient propulsion, a propulsor should act on a large mass of fluid with minimal acceleration. The design of a propulsor is often tailored to the specific flight speed of the aircraft it powers, aiming to match the jet velocity to the flight speed for optimal efficiency.34