- #1
Saladsamurai
- 3,020
- 7
Homework Statement
A gas enters a compressor and is compressed isentropically. Does the specific enthalpy (h) increase or decrease as the gas passes from inlet to exit?
Homework Equations
[tex]\left(\frac{\partial{h}}{\partial{p}} \right)_s= v\qquad(1)[/tex]
The Attempt at a Solution
Since the specific volume v is a positive number we know that pressure increases (since it is being compressed), then the enthalpy must also increase.
This is the answer that was given in the book. I don't really like it. The left side of (1) is a differential change and hence the right hand side is a single value. When we extend this idea to a finite change, what happens to the right hand side?
Does anyone see what I mean by "I don't like it?" We are looking at values of h and p at two different states 1 and 2. But what the heck is v supposed to do?
I feel like to get the full story, we would need to integrate dh = v(p) dp. We know that v should decrease with an increase in p. Any thoughts?