Beginner's Guide to Propulsion Propulsion Index Welcome to the Beginner's Guide to Propulsion.
Propulsion means to push forward or drive an object forward.
A propulsion system is a machine that produces thrust to push an object forward. On airplanes, thrust is usually generated through some application of Newton's third law of action and reaction. A gas, or working fluid , is accelerated by the engine, and the reaction to this acceleration produces a force on the engine. A general derivation of the thrust equation shows that the amount of thrust generated depends on the mass flow through the engine and the exit velocity of the gas. Different propulsion systems generate thrust in slightly different ways.