liquid thermal expansion calc - help needed
liquid thermal expansion calc - help needed
(OP)
I have density data that shows this liquid is 55.9 lb/ft3 at 200'F and 53.7 lb/ft3 at 300'F. What is the thermal expansion coefficient (beta)?
I have tried inverting the density adn calculating (0.0186-0.0179)/100 = 0.000007 but that number seems too small compared to similar fluids. What is the right way to do this?
TYIA,
Heater Guy
I have tried inverting the density adn calculating (0.0186-0.0179)/100 = 0.000007 but that number seems too small compared to similar fluids. What is the right way to do this?
TYIA,
Heater Guy





RE: liquid thermal expansion calc - help needed
B = 1/V ( dV/ T)
where B = thermal expansion coefficient, V = Volume, dV = change in Volume, and T = change in temperature.
Your method looks right. Have you checked the units?
RE: liquid thermal expansion calc - help needed
beta = (dV/V0)/dT (PS: I am using d instead of delta and this is not a differentiation)
RE: liquid thermal expansion calc - help needed
It seems we have posted at the same time.
RE: liquid thermal expansion calc - help needed
I hope heaterguy is now satisfied with the cubic thermal expansion value estimated by quark in 1/oF. When using oC the result should be multiplied by 1.8 .
RE: liquid thermal expansion calc - help needed
RE: liquid thermal expansion calc - help needed
The information you provided is not enough to calculate the term BETTA. Unless, the pressure at the two conditions is the same.
RE: liquid thermal expansion calc - help needed
In theory sailoday28 is right. The definition of the cubic thermal expansion β, sometimes called alpha, is:
However, the isothermal compressibility values
are quite small when the liquids are well below their normal boiling points, usually lower than 2×10-4/atm, to sensibly affect the definition given by quark.
RE: liquid thermal expansion calc - help needed
Can you explain in layman terms--How did you display the partials?
Thanks
RE: liquid thermal expansion calc - help needed
Knowing the liquid might give more of a handle on determining Betta.
RE: liquid thermal expansion calc - help needed
RE: liquid thermal expansion calc - help needed
which in this case would result in:
RE: liquid thermal expansion calc - help needed
I was using either of the densities, but it makes more sense to use the average of the two. Thanks.
heaterguy