Entropy and Entropy Generation

Question 1

What are the features of a reversible expansion?

Answer 1

• No Entropy Generation
• Ordered and Frictionless Motion

Question 2

What are the features of an irreversible expansion?

Answer 2

• Entropy Generation
• Disordered Motion
• Friction in Motion
• Turbulence Present

Question 3

What are some irreversibilities?

Answer 3

• Friction
• Viscous Flow
• Turbulence
• Heat transfer from a hotter body to a colder body
• Mixing of two different substances
• Any deviation from a quasi-static process

Question 4

What are the modes of entropy transfer?

Answer 4

• Heat
• Mass Transfer

Question 5

How is heat a mode of entropy transfer?

Answer 5

It’s a dissipative form of energy. Every heat transfer through a finite temperature difference generates entropy, meaning that heat transfer must cause entropy transfer

Question 6

How is mass transfer a form of entropy transfer?

Answer 6

Because all mass contains entropy. This means that mass passing through the system means that entropy also passes through the system

Question 7

Does work generate entropy?

Answer 7

No

Question 8

What is the entropy transferred through a point on a surface?

Answer 8

Heat transfer through the boundary / Boundary temperature

Question 9

What is the Entropy Transfer due to Mass?

Answer 9

Mass flow rate * Specific Entropy