ABSTRACT
Both air-breathing and non-air-breathing (rocket) engines work on the principle of jet propulsion, but the air-breathing engine is different from the rocket engine in the sense that it carries both fuel and oxidizer during its flight. This chapter discusses the elements of rocket propulsion in detail. It also defines and discusses the performance parameters, namely, specific impulse, impulse to weight ratio, specific propellant flow rate, mass flow coefficient, thrust coefficient, characteristic velocity, and propulsive efficiencies, which are useful in characterizing rocket engines. In modern times, it is important to know how much fuel is being burnt for unit power produced in heat engines. The various kinds of efficiencies, namely, propulsive, thermal, overall efficiencies, and others for the rocket engine to analyze the performance of energy conversion need to be evaluated during its operation. The overall efficiency is the ratio of thrust power to the total chemical energy consumption rate from the propellant.
