Glossary
to accompany
Thermodynamics: An Engineering Approach, 5th edition
by Yunus A. Çengel and Michael A. Boles
47
Steam generator is the combination of a boiler and a heat exchanger section (the
superheater), where steam is superheated.
Steam power plant is an external-combustion engine in which steam (water) is the
working fluid. That is, combustion takes place outside the engine, and the thermal energy
released during this process is transferred to the steam as heat. A turbine in the power
plant converts some of the energy of the steam into rotating shaft work.
Stefan-Boltzmann law gives the maximum rate of radiation that can be emitted from a
surface as product of the Stefan-Boltzmann constant, surface area, and the fourth power
of the surface absolute temperature.
Stirling cycle is made up of four totally reversible processes:
1-2 T constant expansion (heat addition from the external source),
2-3 v constant regeneration (internal heat transfer from the working fluid to the
regenerator),
3-4 T constant compression (heat rejection to the external sink),
4-1 v constant regeneration (internal heat transfer from the regenerator back to the
working fluid).
Stoichiometric air is the minimum amount of air, also called theoretical air, needed for
the complete combustion of a fuel. When a fuel is completely burned with theoretical air,
no uncombined oxygen will be present in the product gases.
Stoichiometric coefficients are the mole numbers in the stoichiometric (theoretical)
reaction.
Stoichiometric combustion (theoretical combustion) is the ideal combustion process
during which a fuel is burned completely with theoretical air.
Stoichiometric (theoretical) reaction is the balanced reaction equation for a chemical
equilibrium reaction.
Stream exergy (see flow exergy)
Stroke is the distance between the top dead center and the bottom dead center and is the
largest distance that the piston can travel in one direction within a cylinder.
Strong oblique shocks are straight oblique shocks that have the larger possible values of
the shock angles for deflection angles less than the maximum deflection angle.
Subcooled liquid has a temperature less than the saturation temperature corresponding to
the pressure.