Combustion is the process that heats the working fluid in a jet engine. Combustion is a particular chemical reaction that has the following specific characteristics: (1) it is exothermic, (2) it is a fast oxidation of the combustion mixture, and (3) it is associated by light emission. The majority of chemical reactions take place in the flame, which is the region where the oxidation is visible.

This chapter presents a thermodynamic analysis of various types of jet engines. The general thrust equation, introduced based on simple reasoning in , is derived using a rigorous approach based on mass and momentum conservation equations. The performance parameters needed to evaluate propulsion systems are presented next. The Brayton cycle, the ideal cycle of a jet engine, is then discussed. The assumptions of the Brayton cycle are gradually relaxed, and the real cycles of turbojet, turbofan, turboprop/turboshaft and ramjet engines are subsequently presented.

The mass, momentum, and energy balance equations and the second law of thermodynamics equation are used to model the transport phenomena in propulsion systems. A simplified version of these equations that assumes the flow is steady and one-dimensional is frequently used for the pre-design and analysis of the propulsion systems.

This chapter presents a review of the laws that govern the aerodynamics and thermodynamics of gases in jet engines. Mastery of these laws is crucial for understanding why and how propulsion systems work. This chapter is divided into two parts: conservation laws and thermodynamics laws. This split is somewhat arbitrary since conservation laws and thermodynamics laws overlap. For example, the energy conservation law is also known as the first law of thermodynamics.

In , the total and specific impulse were introduced since they were used in comparing different types of rocket engines. It was illustrated there that the specific impulse is an important indicator of efficiency and overall system performance. This chapter presents the general equations and parameters that measure chemical rocket performance as a function of the propellant and chamber characteristics, nozzle design, and operating altitude.

This introductory chapter starts with a classification of propulsion systems. This allows us to get familiar with some of the nomenclature used in this text. A brief history of jet propulsion is presented in order to understand the evolution of propulsion systems. The jet propulsion principle is then presented, and the expression of jet engine thrust is introduced using elementary arguments. A rigorous derivation of the thrust expression will be presented in .

This chapter presents the main jet engine components: inlet diffuser, compressor, combustor, turbine, and exit nozzle. Typical configurations are presented for each component, followed by a description of the main processes and parameters. The performance of each component is then related to the engine real cycle, which establishes a tight connection between this chapter and . The section describing the combustors is also connected toand .

Rocket propulsion is a form of jet propulsion where mass (or matter) is accelerated from storage to high exit velocities. Rockets differ from typical air-breathing jet propulsion in that the rocket vehicle itself supplies all the propellant for the rocket motor. The exception to this is the mixed-mode (or multi-mode) engine that will be discussed later in this chapter.