basic problem involving Internal energy and entropy of a vessel
basic problem involving Internal energy and entropy of a vessel
(OP)
The problem is:
A 2ft^3 vessel is filled w/ 1 lbm of water at 100psia. What is the total internal energy and entropy of the vessel?
It's been a while since working a problem like this, any ideas?
Everything is greatly appreciated, many thanks in advance
A 2ft^3 vessel is filled w/ 1 lbm of water at 100psia. What is the total internal energy and entropy of the vessel?
It's been a while since working a problem like this, any ideas?
Everything is greatly appreciated, many thanks in advance





RE: basic problem involving Internal energy and entropy of a vessel
You have P= 100psia, and v= 2./1. = 2 ft3/lbm.
so now use a steam table and obtain the rest.
RE: basic problem involving Internal energy and entropy of a vessel
Since 0.5 lb/cf is not the density of the water at 100 psia, can you tell us the temperature?
RE: basic problem involving Internal energy and entropy of a vessel
from the following online steam tables
<http://www.steamtablesonline.com/steam97web.aspx>
p=100., T= 327.8, v= 2.0, h= 697.7, s=0.981216
units are english units, not metric.
RE: basic problem involving Internal energy and entropy of a vessel
RE: basic problem involving Internal energy and entropy of a vessel
My steam tables didn't show a value for the given data. Therefore I had to assume it is a mixture of liquid and vapor.
It appears to be wet steam with a 44.9% quality as shown by the "calculator" suggested by davefitz.
RE: basic problem involving Internal energy and entropy of a vessel
I was referring to dry steam. I agree with you that wet steam (44.9% dryness) has the values of enthalpy reported by davefitz
RE: basic problem involving Internal energy and entropy of a vessel
RE: basic problem involving Internal energy and entropy of a vessel
It cannot apply when the two given properties are saturation pressure and temperature. In this case one needs an extensive property.
RE: basic problem involving Internal energy and entropy of a vessel
Or, of course, the steam quality.
RE: basic problem involving Internal energy and entropy of a vessel
Or specific volume, which is another intensive property.