Thermodynamics II
Assistant Professor Dr Ahmed Majhool
CHAPTER 7:ENTROPY
1
ENTROPY
Clasius inequality
Thermodynamics II
Assistant Professor Dr Ahmed Majhool
Formal definit
The equality in the Clausius inequality holds for t
2
A quantity whose cyclic integral is zero (i.e., a prope
Entropy is an extensive property of a system.
Thermodynamics II
Assistant Professor Dr Ahmed Majhool
A Special Case: Internally Reversible
Isothermal Heat Transfer Processes
This equation is particularly useful for determining the entropy change
HE INCREASE OF ENTROPY
PRINCIPLE
Thermodynamics II
Assistant Professor Dr Ahmed Majhool
The equality holds for an internally revers
Some entropy is generated or created during an irreversible process, and this gene
The entropy generation Sgen is always a positive quantity or zero.
Can the entropy of a system during a process decrease?
Thermodynamics II
Assistant Professor Dr Ahmed Majhool
The increase of entropy principle
1. Processes can occur in a certain direction o
Some Remarks about
Entropy
2. Entropy is a nonconserved property, and th
Thermodynamics II
Assistant Professor Dr Ahmed Majhool
3. The performance of engineering systems is
ENTROPY CHANGE OF PURE SUBSTANCES
Thermodynamics II
Assistant Professor Dr Ahmed Majhool
Entropy is a property, and thus the value of entropy of a system is fixed once the
Entropy change
ISENTROPIC PROCESSES
Thermodynamics II
Assistant Professor Dr Ahmed Majhool
A process during which the entropy remains constant is called an isen