I dont know is your papers main idea stated clearly?
Answer:
The entropy change of the air is 
Explanation:

is unknown
we can apply the following expression to find 


now substitute

To find entropy change of the air we can apply the ideal gas relationship
Δ

Δ

Δ
Complete Question
Complete Question is attached below.
Answer:

Explanation:
From the question we are told that:
Diameter 
Power 
Head loss 




Generally the equation for Power is mathematically given by

Therefore



Since

Where


Therefore


Answer: Kinetic energy
Explanation: If you live in a country other than UK you will probably call it something different