Glossary
to accompany
Thermodynamics: An Engineering Approach, 5th edition
by Yunus A. Çengel and Michael A. Boles55Weight is the gravitational force applied to a body, and its magnitude is determined from
Newton’s second law.
Wet-bulb temperature is temperature measured by using a thermometer whose bulb is
covered with a cotton wick saturated with water and blowing air over the wick.
Wet cooling tower is essentially a semienclosed evaporative cooler.
Wet region (see saturated liquid–vapor mixture region)
Wilson line is the locus of points where condensation will take place regardless of the
initial temperature and pressure as steam flows through a high-velocity nozzle. The
Wilson line is often approximated by the 4 percent moisture line on the h-s diagram for
steam. Therefore, steam flowing through a high-velocity nozzle is assumed to begin
condensation when the 4 percent moisture line is crossed.
Work is the energy transfer associated with a force acting through a distance.
Work transfer is the energy in the form of work that is transferred across a system
boundary.
Working fluid is the fluid to and from which heat and work is transferred while
undergoing a cycle in heat engines and other cyclic devices.
Zeroth law of thermodynamics states that if two bodies are in thermal equilibrium with
a third body, they are also in thermal equilibrium with each other. By replacing the third
body with a thermometer, the zeroth law can be restated as two bodies are in thermal
equilibrium if both have the same temperature reading even if they are not in contact.