Thermodynamics Flashcards
when two bodies have equality of temperature with a
third body, they in turn have equality of temperature with each
other.
Zeroth Law
Also known as the Conservation of Energy principle,
states that energy can neither be created nor destroyed, it can only change form
First law of thermodynamics
Deals with the quality of energy (energy
degradation). There are two classical statements of this law:
It is impossible to construct a device that will
operate in a cycle and produce no effect other than the raising of a
weight and the exchange of heat with a single reservoir.
: It is impossible to construct a device that operates
in a cycle and produces no effect other than the transfer of heat from a
cooler-body to a hot
Second law of thermodynamics
It is impossible to construct a device that will
operate in a cycle and produce no effect other than the raising of a
weight and the exchange of heat with a single reservoir.
Kelvin Planck Statement
It is impossible to construct a device that operates
in a cycle and produces no effect other than the transfer of heat from a
cooler-body to a hot
• Clausius statement
states that the entropy of a perfect crystal is zero at
the absolute zero of temperature.
Third law of thermodynamics
the
science that deals with the study of energy and
entropy;
Thermodynamics
it
deals
with
the
properties
of
matter/substance related to heat and work;
Thermodynamics
it deals
with processes and cycles on the transformation of
energy of all kinds, from one form to another.
Thermodynamics
deals with processes of cooling; it deals
with the processes and cycles of different methods of
refrigeration;
Refrigeration
condition of a substance as
described by certain observable macroscopic
parameter called Properties
State of Substance
quantity of matter that is homogeneous
throughout(solid, liquid, gas)
Phase-
Solid to Liquid
Melting
Liquid to Solid
Solidification (Freezing)
Liquid to Gas
Evaporation
Gas to liquid
Condensation
Solid to Gas
Sublimation
Gas to Solid
Deposition
Simply the change of state
Process
constant temperature.
Isothermal
constant pressure
Isobaric
constant volume
Isometric/isovolumetric
constant entropy
Isentropic
constant enthalpy
Isenthalpic
PV^n = C
Polytropic
a series of processes one after the other such
that the initial and final states are the same.
Cycle
Measures of the degree of hotness or coldness of a body
Temperature
If the temperature of a given quantity of gas is held
constant, the volume of the gas varies inversely
with the absolute pressure during a change of
state.
Boyle’s Law
Specific gravity is always _____ to rate of density
Equal
If the pressure on a particular quantity of gas is
held constant, then, with any change of state, the
volume
will
vary
directly
as
the
absolute
temperature.
Charle’s Law
If the volume of a particular quantity of gas is held
constant, then, with any change of state, the
pressure will vary directly as the absolute
temperature.
Gay-Lussac’s Law
the change of internal energy
of an ideal gas is a function of only the temperature
change.
Joule’s law
Thermodynamics cycle used in vapor power plants
Rankine
Kinetic energy is the energy of the body due to its:
Motion
The state of a pure substance is defined completely if
we define
two independent intensive
properties
An isentropic process is used to approximate an actual
process. For such a process
the heat transfer is zero
The amount of transferred heat required to change
the temperature of unit weight of substance at one degree unit of temperature.
Specific heat
A gas turbine works on the principle of
Brayton Cycle
The absolute zero temperature in Celsius scale.
-273
Torque is a force that tend to produce
Rotation
The process that has no heat transfer
Isentropic/Adiabatic
The boiling point
of water
in an
open
container
at sea
level is 100
o
C. If the
pressure
on
the open
container
is
decreased such as going up to the top of a mountain,
the boiling point will be
Decreased
A rigid container is heated by the sun. There is no shaft
work associated with the container. From the first law
of thermodynamics. You determine the heat added to
be
equal to the change in internal
energy
A device used to keep moisture from passing through
the system
dehydrator
An adiabatic process is characterized by which of the
following?
heat transfer is zero
As heat is removed from a substance it gets colder.
When no more heat can be removed and the
temperature cannot be lowered any further, we
have reached
absolute zero
A 100% efficient pump can draw a suction of.
34 ft H2O
- 7 Psi
- 92 in Hg
• If the temperature of the medium is 0 C, what will
be the temperature if it is doubled?
273 C
• A closed system experiences a reversible process
where heat rejection is the only energy transferred.
The entropy change must be
negative
If a centrifugal pump tends to vibrate, it might be
caused by:
misalignment
worn bearings
clogged or damaged impeller
A manometer measures:
Pressure
A pump is used to increase the pressure of the water
entering the boiler of steam power cycle. Which
statement is true concerning the pump?
The enthalpy of water leaving the pump is higher than the
enthalpy of water entering
• A pyrometer measures:
Temperature
The steam power cycle is modeled by ideal cycle
known as the:
Rankine
• An open system first law should be utilized for
turbine
. pump
boiler
An inventor claims to have built an engine which will
revolutionize the automotive industry. Which of the
following should be the best test to determine if the
inventors claim is true?
Second law of thermodynamics
In an ideal cycle, liquid leaves the condenser and is
expanded in such a manner that the enthalpy of the liquid is
equal to the enthalpy of the resulting saturated mixture.
This type of expansion is known as:
throttling process
• A type of process where the pressure remains
constant
Isobaric
A type of process where the temperature remains
constant
Isothermal
• A type of process where the volume remains constant
Isometric / isovolumetric
Transformation of energy from one form to another
Thermodynamics
Father of thermodynamics
Nicolas Leonardo Sadi Carnot
Properties that are independent of the size (mass) of a system, such as temperature, pressure and density
Intensive Properties
Values that are dependent on size of the system such as mass, volume and total energy
Extensive Properties
The measure of the amount of material present in the body
Mass
The force exerted by that body when its mass is accelerated in a gravitational field
Weight
The ratio of total mass and total volume or the mass per unit volume
Density
Reciprocal of specific volume
Density
Ratio of total volume and total mass or the volume per unit mass of the substance
Specific volume
The Force of gravity on unit volume
Specific Weight
Measure of relative density of a substance as compared to the density of water at a standard temperature for liquid density of air for gases
Specific gravity
It is dimensionless property whose values for liquid varies with temperature
Specific Gravity
A measure of the molecular activity of a substance or the internal energy of a hody
Temperature
Refers to temperature measured from absolute zero
Absolute temperature
Molecular state where there is no molecular mostion of individual atoms
Absolute zero temperature
