1. ENGINEERING THERMODYNAMICS
M.R.SWAMINATHAN
Assistant Professor
Internal Combustion Engineering Division
Department of Mechanical Engineering
ANNA UNIVERSITY
CHENNAI-25.

2. PROPERTIES- contd.
CYCLE
A process (or a series of connected processes) with identical end states is called a cycle.
A cycle composed of two processes, A and B.
all other thermodynamic properties must also change

3. Other thermodynamic properties must also change so that the pressure is a function of volume as described by these two processes
Process B A 1 2 P V

4. EQUILIBRIUM
A system is said to be in thermodynamic equilibrium if it maintains
Thermal (Uniform Temperature)
Mechanical (Uniform Pressure)
Phase equilibrium
Chemical equilibrium.

6. QUASISTATIC PROCESS Process proceeds in such a way that
the system remains infinitesimally
close to an equilibrium state at all
times, it is called a quasistatic,
or quasi-equilibrium process

7. QUASISTATIC PROCESS Quasi- equilibrium process can be
viewed as a sufficiently slow process
that allows the system to adjust itself
internally so that properties in one
part of the system do not change any
faster than those at other parts

8. QUASISTATIC PROCESS

9. QUASISTATIC PROCESS

10. ZEROTH LAW
Zeroth law was first formulated and labeled by R. H. Fowler in 1931
Two bodies are in thermal equilibrium if both have the same temperature even if they are not in contact.

11. HEAT
Heat is defined as the form of energy that is transferred between two systems (or a system and its surroundings) by virtue of a temperature difference.
Heat is energy in transition.

12. HEAT
Heat is energy in transition. It is recognized only as it crosses the boundary of a system
The potato contains energy, but this energy is heat transfer only as it passes through the skin of the potato (the system boundary) to reach the air, as shown in figure.

13. HEAT

14. HEAT

15. HEAT TRANSFER

16. WORK
Work, like heat, is an energy interaction between a system and its surroundings.
Energy can cross the boundary of a closed system in the form of heat or work.

17. WORK
Work is the energy transfer associated with a force acting through a distance.

18. HEAT AND WORK
Heat and work are directional quantities.

19. HEAT AND WORK

20. HEAT & WORK SIMILARITY
Heat and work are energy transfer mechanisms between a system and its surroundings.
Systems possess energy, but not heat or work.
Both are recognised at the boundaries of a system as they cross the boundaries.
Both are path functions