The propulsive efficiency of a propulsion system, such as a jet engine or a propeller, typically calculates the ratio of the useful power output (thrust) to the power input (fuel energy). The formula for propulsive efficiency is:
The propulsive efficiency of a propulsion system, such as a jet engine or a propeller, typically calculates the ratio of the useful power output (thrust) to the power input (fuel energy). The formula for propulsive efficiency is: