"A propeller is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral, that, when rotated, performs an action which is similar to Archimedes´ screw. It transforms rotational power into linear thrust by acting upon a working fluid, such as water or air. The rotational motion of the blades is converted into thrust by creating a pressure difference between the two surfaces. A given mass of working fluid is accelerated in one direction and the craft moves in the opposite direction. Propeller dynamics, like those of aircraft wings, can be modelled by Bernoulli´s principle and Newton´s third law. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft with an approximately horizontal axis." - (en.wikipedia.org 13.05.2021)
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