# Mechanical Engineering - Thermodynamics - Discussion

Discussion Forum : Thermodynamics - Section 2 (Q.No. 14)
14.
The greater the pressure difference in throttling, the lesser is the irreversibility.
Yes
No
Explanation:
No answer description is available. Let's discuss.
Discussion:
9 comments Page 1 of 1.

There is a temperature difference during throttling process. Then how can we say that throttling process is isenthalpic procese?

Sounds prakash said:   7 years ago
See Irreversibility= T * (change in entropy).
Now for change in entropy we know.
S = dh- vdp
But dh = 0 ( for throttling)
Now (chng in entropy) = -Rln ( P2/P1).

As asked with an increase in pressure difference the change in entropy value decreases which implies that " Irreversibility" also decreases. U can take any value of P1 and P2 and check eg 2 bars and 5 bar diff 3.

Then 3 bar and 7 bar diff 4, notice then change in entropy is decreasing so Irreversibility decreases.
(1)

RAMESH said:   8 years ago
Throttling is a irreversible process. For example if steam is leakage from a pipeline. Here the heat transfer take place from pipeline to the surrounding, but there is no workdone here. That mean there is no chance to flow the steam in reverse in direction. Hence throttling process is said to be "Irreversible Process ".

Irreversible mean loss in availability due to friction. That is loss in available work done. When the pressure difference is more there is more in loss of work. That mean loss in available energy is decrease. So Irreversibility is Increases.
(1)

Vasu said:   8 years ago
What is meant by irreversible process?

Samrat said:   8 years ago
Throttling process is also irreversible flow process.

Mohammed Riyas said:   8 years ago
Throttling should be an irreversible flow process.

Vishal said:   8 years ago
Throttling result in decreases pressure.

Vaibhav kumbhar said:   9 years ago
Throttling process cannot be irreversible.

Roy said:   10 years ago
Lesser the potential gradient lesser is the irreversibility of the process. For an infinitesimally less (limiting to zero) potential gradient, the process becomes reversible.