Glossary
to accompany
Thermodynamics: An Engineering Approach, 5th edition
by Yunus A. Çengel and Michael A. Boles22Generalized enthalpy departure chart is a plot of the enthalpy departure factor as a
function of reduced pressure and reduced temperature. It is used to determine the
deviation of the enthalpy of a gas at a given P and T from the enthalpy of an ideal gas at
the same T.
Generalized entropy departure chart is a plot of the entropy departure factor as a
function of reduced pressure and reduced temperature. It is used to determine the
deviation of the entropy of a gas at a given P and T from the entropy of an ideal gas at the
same P and T.
Generator efficiency is defined as the ratio of the electrical power output to the
mechanical power input to a generator.
Geothermal heat pumps (also called ground-source heat pumps) use the ground as the
heat source.
Gibbs–Dalton law, an extension of Dalton’s law of additive pressures, states that under
the ideal-gas approximation, the properties of a gas in a mixture are not influenced by the
presence of other gases, and each gas component in the mixture behaves as if it exists
alone at the mixture temperature and mixture volume.
Gibbs function is defined as the enthalpy minus the product of the temperature and
entropy (G = H - TS).
Gibbs phase rule provides the number of independent variables associated with a
multicomponent, multiphase system.
Gravimetric analysis is one way to describe the composition of a mixture that is
accomplished by specifying the mass of each component.
Gravitational acceleration g is 9.807 m/s^2 at sea level and varies by less than 1 percent
up to 30,000 m. Therefore, g can be assumed to be constant at 9.81 m/s
2
.Greenhouse effect is the heating effect causing the increase in temperature of the earth’s
atmosphere as the result of solar radiation entering the earth’s atmosphere during the day,
but heat radiated by the earth at night is blocked by gases such as carbon dioxide and
trace amounts of methane, nitrogen oxides and other gases.
Gobal climate change (see global warming).
Global warming (global climate change) is the undesirable consequence of the
greenhouse effect.
Heat (see heat transfer).