Burt Rutan's White Knight and SpaceShip One, Photo Courtesy of Scaled Composites
Thermodynamics and Propulsion

9.2 Performance parameters

The two performance parameters of greatest interest for a propulsion system are the force it produces (thrust, $ T$ ), and the overall efficiency with which it uses energy to produce this force ( $ \eta_{\textrm{overall}}$ ). We will begin by looking at the production of thrust using the integral form of the momentum theorem. We will then discuss the efficiency of propulsion systems.