Glossary
to accompany
Thermodynamics: An Engineering Approach, 5th edition
by Yunus A. Çengel and Michael A. Boles4where the constants for various substances are given in Table 2-4.
Bernoulli equation is the result of the energy analysis for the reversible, steady-flow of
an incompressible liquid through a device that involves no work interactions (such as a
nozzle or a pipe section). For frictionless flow, it states that the sum of the pressure,
velocity, and potential energy heads is constant. It is also a form of the conservation of
momentum principle for steady-flow control volumes.
Binary vapor cycle is a vapor cycle in which the condenser of the high-temperature
cycle (also called the topping cycle) serves as the boiler of the low-temperature cycle
(also called the bottoming cycle). That is, the heat output of the high-temperature cycle is
used as the heat input to the low-temperature one.
Blackbody is an idealized surface that emits radiation at the maximum rate given by the
Stefan-Boltzmann law.
Blackbody radiation is amount of radiation emitted by a blackbody.
Boiler is basically a large heat exchanger where the heat originating from combustion
gases, nuclear reactors, or other sources is transferred to the water essentially at constant
pressure.
Boiling is the phase change process that occurs at the solid–liquid interface when a liquid
is brought into contact with a surface maintained at a temperature sufficiently above the
saturation temperature of the liquid.
Boltzmann relation is the expression of the entropy as a function of thermodynamic
probability.
Boltzmann’s constant, k has the value of 1.3806 × 10
23
J/K.Bore is the diameter of a piston.
Bottom dead center BDC is the position of the piston when it forms the largest volume
in the cylinder.
Bottoming cycle is a power cycle operating at lower average temperatures that receives
heat from a power cycle operating at higher average temperatures.
Boundary is the real or imaginary surface that separates the system from its
surroundings. The boundary of a system can be fixed or movable.