Propulsion mechanics and applications

Abstract

Propulsion (or reaction) engines are based on the principle of reaction discovered by Heron of Alexandria in the first century BCE, and formulated by Newton in the 17th century: for each action there corresponds a reaction of equal intensity, but directed in the opposite direction. The reactors are therefore only devices intended to eject gases at high speed, so that it results in a "thrust" which is transmitted to the aircraft and forces it to move in the opposite direction to the direction according to which it is exercised. The propulsion mechanism does not require ambient air as a medium but it does involve the presence of at least two bodies. Indeed, for land vehicles the reaction (propelling effect) is exerted by a fixed support which is the ground.