# N2 gas temperature change by different compression/expansion speeds

1. May 11, 2010

### hyeonje

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?

Hyeonje

2. May 12, 2010

### Q_Goest

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.

3. May 12, 2010