ENGR 2213 Thermodynamics
F. C. Lai
School of Aerospace and Mechanical
Engineering
University of Oklahoma
Syllabus
Instructor
Dr. F. C. Lai (FH 218A)
Phone: 325-1748, Fax: 325-1088, Email: flai@ou.edu
Office Hours: 14:00-15:00 MTWR or by appointment
Textbook
Thermodynamics – An Engineering Approach
by Y. A. Çengel and M. A. Boles, 4th edition,
McGraw-Hill, 2002.
Course Outline
Introduction (1+)
● Basic Concepts
● Properties
First Law (2-6)
● Energy Analysis for Closed System
● Energy Analysis for Control Volumes
Second Law (7-12)
● Entropy
● Exergy (Availability)
Course Outline
Power Systems (12-16)
● Vapor Power Systems
● Gas Power Systems
Grade
● Homework (8-10)
● Quizzes (3)
● Final Exam
25%
45%
30%
Final grade (in absolute scale)
85+
75-84
65-74
55-64
55-
A
B
C
D
F
Introduction
Thermo-
dynamics
heat
force
● Energy
→ Engineers
● Properties of Matter → Scientists
History of Development
~1700
Building a steam engine
(T. Savery and T. Newcomen)
1849
First use of the term “Thermodynamics”
(Lord Kelvin)
1859
First textbook of “Thermodynamics”
(W. Rankine)
>1900
Become a mature science
Approaches
Macroscopic Approach (Classical Thermodynamics)
- is concerned with the overall behavior of a system
- no model of the structure of matter at the molecular, atomic,
and subatomic level is directly use
Microscopic Approach (Statistical Thermodynamics)
- is concerned directly with the structure of matter
- characterize, by statistical means, the average behavior of
the particles making up a system of interest and relate this
information to the observed macroscopic behavior of the
system
Definitions
• System
• Surroundings
• Boundary
system
the subject of the analysis
everything external to the
system
the surface that separates the
system from its surroundings
surroundings
Definitions
• System
• Surroundings
• Boundary
the subject of the analysis
everything external to the
system
the surface that separates the
system from its surroundings
boundary
Systems
Closed Systems
-
A fixed quantity of matter
There can be no transfer of mass across its boundary
Energy, in the form of heat or work, can cross the boundary
The volume of a closed system does not have to be fixed
Control Volumes
- A fixed volume in space through which mass may flow
- It usually enclose a device which involves mass flow
such as a compressor, turbine, or nozzle
Systems
Piston and Cylinder
Assembly
Closed System
Water Heater
Systems
Piston and Cylinder
Assembly
Closed System
Water Heater
Control Volume
Properties
Macroscopic characteristics of a system to which
numerical values can be assigned.
Extensive Properties
Properties that their values depend on the size or extend
of a system.
Examples: mass, volume
Intensive Properties
Properties that their values are independent of the size
or extend of a system.
Examples: temperature, pressure
Properties
● Divide and Conquer
● Rule of “Sum”
For a quantity, if its value for a system is the sum of its
values of each partition, then it is an extensive property.
Properties
● Divide and Conquer
● Rule of “Sum”
For a quantity, if its value for a system is the sum of its
values of each partition, then it is an extensive property.
M = M 1 + M2 + M3 + M 4
Mass is an extensive property
1
2
3
4
Properties
● Divide and Conquer
● Rule of “Sum”
For a quantity, if its value for a system is the sum of its
values of each partition, then it is an extensive property.
V = V1 + V2 + V3 + V4
Volume is an extensive property
1
2
3
4
Properties
● Divide and Conquer
● Rule of “Sum”
For a quantity, if its value for a system is the sum of its
values of each partition, then it is an extensive property.
P = P1 = P2 = P3 = P4
1
2
3
4
Pressure is not an extensive
property
Properties
● Divide and Conquer
● Rule of “Sum”
For a quantity, if its value for a system is the sum of its
values of each partition, then it is an extensive property.
T = T1 = T2 = T3 = T4
1
2
3
4
Temperature is not an extensive
property
Properties
Specific Properties
- Extensive properties per unit mass
- A specific property is an intensive property
Examples: specific volume
V
v
m
m

V
density
Basic Concepts
State
The condition of a system as described by its properties
Process
A transformation from one state to another
At a given state, each property has a definite value that is
Independent of how the system arrived at that state.
Basic Concepts
The change in value of a property as the system is altered
from one state to another is determined solely by the two
end states and is independent of the particular way the
change of state occurred.
A quantity is a property if, and only if, its change in value
between two states is independent of the process.
Basic Concepts
Denver
OKC
Latitude
Denver 39º 45’
OKC
35º 24’
Longitude
104º 52’
97º 36’
Elevation
5280’
1285’
Basic Concepts
Phase
A quantity of matter that is homogeneous throughout in
both chemical composition and physical structure.
Homogeneous in physical structure means that the
Matter is all solid, all liquid, or all vapor (gas).
A system can contain one or more phases.
For example:
water and vapor
2 phases
Basic Concepts
Phase
A quantity of matter that is homogeneous throughout in
both chemical composition and physical structure.
Homogeneous in physical structure means that the
Matter is all solid, all liquid, or all vapor (gas).
A system can contain one or more phases.
For example:
water and vapor
2 phases
water and oil
2 phases
Basic Concepts
Phase
A quantity of matter that is homogeneous throughout in
both chemical composition and physical structure.
Homogeneous in physical structure means that the
Matter is all solid, all liquid, or all vapor (gas).
A system can contain one or more phases.
For example:
water and vapor
2 phases
water and oil
2 phases
water and alcohol
1 phase
Basic Concepts
Phase
A quantity of matter that is homogeneous throughout in
both chemical composition and physical structure.
Homogeneous in physical structure means that the
Matter is all solid, all liquid, or all vapor (gas).
A system can contain one or more phases.
For example:
water and vapor
2 phases
water and oil
2 phases
water and alcohol
1 phase
oxygen and nitrogen
1 phase
Basic Concepts
Pure Substance
One that is uniform and invariable in chemical
composition
A pure substance can exist in more than one phase
A uniform mixture of gases can be regarded as a pure
substance provided it remains a gas and does not react
chemically
Equilibrium
A state of balance
In an equilibrium state, there are no unbalanced
potentials (driving forces) within the system.
Thermodynamic Equilibrium
● Thermal Equilibrium
● Mechanical Equilibrium
● Phase Equilibrium
● Chemical Equilibrium
Thermodynamic Equilibrium
Thermal Equilibrium
●
●
The system involves no temperature differentials
Temperature is uniform in the system
Mechanical Equilibrium
●
●
No change in pressure at any point in the system
The pressure may vary within the system with
elevation as a result of gravitational effect
Thermodynamic Equilibrium
Phase Equilibrium
●
The mass of each phase remains the same
Chemical Equilibrium
●
●
Chemical composition does not change with time
No chemical reactions occur
Basic Concepts
Quasi-Equilibrium Process
A process that proceeds in such a manner that the
system remains infinitesimally close to an equilibrium
state at all times
A quasi-equilibrium process is an idealized process to
approximate an actual process
Basic Concepts
Process Path
The series of equilibrium states through which a system
passes during a process
To describe a process completely, one needs to specify
the initial and final states of the process, as well as the
path it follows
Steady State
Properties of the system does not change with time
Cycle
A sequence of processes that begins and ends at the
same state