Glossary
to accompany
Thermodynamics: An Engineering Approach, 5th edition
by Yunus A. Çengel and Michael A. Boles42Reversible work Wrev is defined as the maximum amount of useful work that can be
produced (or the minimum work that needs to be supplied) as a system undergoes a
process between the specified initial and final states. Reversible work is determined from
the exergy balance relations by setting the exergy destroyed equal to zero. The work W in
that case becomes the reversible work.
Rocket is a device where a solid or liquid fuel and an oxidizer react in the combustion
chamber. The high-pressure combustion gases are then expanded in a nozzle. The gases
leave the rocket at very high velocities, producing the thrust to propel the rocket.
Saturated air is air which can hold no more moisture at its state. Any moisture
introduced into saturated air will condense.
Saturated liquid is a liquid that is about to vaporize.
Saturated liquid line is the saturated liquid states connected by a line that meets the
saturated vapor line at the critical point, forming a dome.
Saturated liquid–vapor mixture (wet region) is a mixture of the liquid and vapor
phases that coexist in equilibrium.
Saturated liquid–vapor mixture region is all the states that involve both the liquid and
vapor phases in equilibrium and are located under the dome.
Saturated vapor is a vapor that is about to condense.
Saturated vapor line is the saturated vapor states connected by a line that meets the
saturated liquid line at the critical point, forming a dome.
Saturation pressure Psat is called the pressure at which a pure substance changes phase
at a given temperature.
Saturation temperature Tsat is the temperature at which a pure substance changes phase
at a given pressure.
Scramjet engine is essentially a ramjet in which air flows through at supersonic speeds
(speeds above the speed of sound).
Secondary dimensions, or derived dimensions, such as velocity, energy E, and volume
V, are expressed in terms of the primary dimensions.
Secondary units are expressed in terms of the primary units.