ABSTRACT
The engineering and design of combustion devices begins with the application of the laws of thermodynamics. Thermodynamics provides the laws of conservation of mass, species, and energy; de–nes ef–ciency; and deals with equilibrium states and chemical composition of the reactants and products. In this chapter we review the –rst law of thermodynamics for closed and open systems, the properties of mixtures, and combustion stoichiometry. In addition we examine the principles of equilibrium, which state how the chemical composition can be determined for a system of known atomic or molecular composition if two independent thermodynamic properties are known. Although systems undergoing chemical reaction are generally far from chemical equilibrium, in many cases of interest a small enough control volume can be selected so that pressure and temperature are uniform within the control volume. The chemical composition at a given instant in time is dictated by the thermodynamic properties, chemical reaction rates, and ¢uid dynamics of the system. In this chapter we assume that chemical reactions are in equilibrium (i.e., not rate controlled) and that there are no gradients and hence no ¢uid dynamics.
