What is Thermodynamics? Applications of Thermodynamics Macroscopic and Microscopic Viewpoint of Thermodynamics Thermodynamic System Closed System Open System Isolated System Control Volume

1. Shaik Nayeem
Thermodynamics
Introduction: Part-1
1
Shaik Nayeem

2. • What is Thermodynamics?
• Applications of Thermodynamics
• Macroscopic and Microscopic Viewpoint of Thermodynamics
• Thermodynamic System
• Closed System
• Open System
• Isolated System
• Control Volume
Contents

3. What is Thermodynamics?
Thermodynamics is the science of energy transfer
and its effect on the physical properties of
substances
Energy can be viewed as the ability to cause
changes
The name thermodynamics comes from the Greek
words therme (heat) and dynamis (power)Shaik Nayeem 3

4. Applications of Thermodynamics
Automotive engines
Turbines
Compressors
Pumps
Fossil and Nuclear Power Plants
Propulsion systems for the Aircrafts
Separation and Liquefaction PlantShaik Nayeem 4

5. Applications of
Thermodynamics(Cont…)
Refrigeration
Air-conditioning and Heating Devices
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6. Macroscopic and Microscopic
Viewpoint of Thermodynamics
The behaviour of a matter can be studied at two levels:
a) Macroscopic b) Microscopic
Macroscopic ( or Classical Thermodynamics)
In this approach, a certain quantity of matter is
considered, without taking into account the events
occurring at the molecular level
In this approach, does not require knowledge of the
behaviour of individual particlesShaik Nayeem 6

7. Macroscopic and Microscopic
Viewpoint of Thermodynamics(Cont…)
It concerns the effects of the action of many
molecules, and these effects can be perceived by
human senses
Macroscopic observations are completely
independent of the assumptions regarding the
nature of matter
Ex: A moving car, a falling stone from a cliff, etc
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8. Macroscopic and Microscopic
Viewpoint of Thermodynamics(Cont…)
Microscopic ( or Statistical Thermodynamics)
In this approach matter is composed of a large number
of small molecules and atoms
It requires the knowledge of behaviour of individual
particles
It concerns with the effects of the action of many
molecules and these cannot be perceived by human
senses Shaik Nayeem 8

9. Macroscopic and Microscopic
Viewpoint of Thermodynamics(Cont…)
The microscopic observations are completely
dependent on the assumptions regarding the
nature of matter
Ex: Individual molecules present in air, etc
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10. Thermodynamic System
Thermodynamic System:
Defined as a quantity of matter or a region in space
upon which attention is concentrated in the analysis of
a problem
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Surrounding:
Everything external to the
system is called surroundings
or the environment

11. Thermodynamic System (Cont…)
Boundary:
A physical or imaginary surface, separating the
system from the surrounding
The boundary may be either fixed or moving
Universe:
System and its surrounding together comprise a
universe Shaik Nayeem 11

12. Thermodynamic System (Cont…)
Three classes of
systems
Closed
system
Open
system
Isolated
system
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13. Closed System
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It is a system of fixed mass
There is no mass transfer across the system
boundary
There may be energy
transfer into or out of
the system

14. Closed System(Cont…)
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Its volume can change against a flexible boundary
A certain quantity of fluid in a cylinder bounded by
a piston constitutes a closed system

15. Open System
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In which matter crosses the boundary of the system
There may be energy transfer also
Most of the engineering devices are generally open
system

16. Open System(Cont…)
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Ex: An air compressor in which air enters at low
pressure and leaves at high pressure and there are
energy transfers across the system boundary

17. Isolated System
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In which there is no interaction between the system
and the surrounding
It is of fixed mass and
energy, and there is no
mass or energy transfer
across the system boundary

18. Isolated System (Cont…)
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19. Control Volume
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For thermodynamic analysis of an open system,
such as an air compressor, attention is focused on a
certain volume in space surrounding the
compressor, known as the “ control volume”,
bounded by a surface called the “ control surface”
Matter as well as energy crosses the control surface

20. Control Volume(Cont…)
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Apart from open system in control volume, the
mass flow rate into and out of the system is
constant

21. Shaik Nayeem 21
Thank You
Shaik Nayeem