N2 gas temperature change by different compression/expansion speeds

Click For Summary
To solve the problem of gas temperature during compression, it is essential to analyze two scenarios: adiabatic compression and compression with heat transfer. In adiabatic compression, the temperature increase is determined by the initial state and final pressure, and it remains unaffected by the rate of compression. Conversely, when heat transfer occurs, the temperature change depends on various factors, including the heat transfer rate, convective heat transfer coefficient, and thermal mass of the container. Understanding these principles is crucial for accurately predicting the gas temperature after compression. This approach will provide a clearer path to finding the answer to the posed question.
hyeonje
Messages
2
Reaction score
0
I am Not familiar with thermodynamics and stucked at work.
Can anyone give an advice how I should approach to get an answer to the example question below please?

If a 1000 cc of N2 gas cylinder is compressed at 100 cc/sec, what would be the gas temperature when the compression is stopped after 5 seconds. The ambient temperature is constant. Would the gas temperature be different if the gas is compressed at a different speed?

Thanks in advance.
Hyeonje
 
Science news on Phys.org
Break the problem up into 2 parts.
1) Adiabatic compression (compression with no heat transfer)
2) Compression with heat transfer

For an adiabatic compression, temperature rise depends on initial state and final pressure. The rate at which the temperature increases is independent of the pressure rise rate.

For compression with heat transfer, you need to determine the rate of heat transfer which is a function of dT, convective heat transfer coefficient, thermal mass of container, etc... There is no straightforward equation.
 
Thanks Q_Goest, your reply helped a lot..

Hyeonje
 
Hello! I have recently been reflecting on the formal structure of the second edition of Callen's Thermodynamics and an Introduction to Thermostatistics. Callen essentially postulates the existence of a function U, called the "internal energy", as a coordinate of thermodynamic systems. He doesn't explicitly say this, but it follows from the rest of the postulates that it must be defined for all equilibrium states, be continuously differentiable, additive over constituent subsystems...

Similar threads

  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 22 ·
Replies
22
Views
6K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
11
Views
9K
  • · Replies 65 ·
3
Replies
65
Views
78K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K