propulsive efficiency-Irfan Mujawar

propulsive efficiency

The propulsive efficiency determines how much of the                          kinetic energy of the exhaust jet is useful for propelling                          a vehicle.
F is the thrust, u the absolute vehicle velocity, c the                                effective rocket exhaust velocity with respect to the                                vehicle, w the propellant weight flow rate, and Flp the                            propulsive efficiency. The propulsive efficiency is a                                maximum when the forward vehicle velocity is exactly                            equal to the exhaust velocity. Then the residual kinetic                            energy and the absolute velocity of the jet are zero and                          the exhaust gases stand still in space.