|
|
Dynamic viscosity report.png (21,545 bytes) |
|
|
Do you have access to the NSRDS tables to check the coefficients? |
|
|
Are you talking about those from the following books: “NSRDS - AICHE Data Compilation Table of Properties of Pure Compounds – T.E Daubert, R.P. Danner” ? If yes, no I don't have access. |
|
|
Correct: NSRDS - AICHE Data Compilation Tables of Properties of Pure Compounds Design Institute for Physical Property Data American Institute of Chemical Engineers 345 East 47th Street New York, New York 10017 National Standard Reference Data System American Institute of Chemical Engineers T.E. Daubert - R.P. Danner Department of Chemical Engineering The Pennsylvania State University University Park, PA 16802 Or a more recent version or the online equivalents. |
|
|
No I don't have access to this book. But I plotted the graph on the left with the coefficient initially set in OpenFOAM which causes this high dynamic viscosity. |
|
|
It is clear that there is a problem with the current coefficients but what is not clear is what the coefficients should be. |
|
|
Yes for sure, I have checked with the other liquids to see if there is a difference regarding the sign or the order of the coefficients for the dynamic viscosity. The only difference I saw is that every coefficient "a" is negative whereas in the liquid nitrogen it is positive. Maybe this correction is valid because it provides me the good range. |
|
|
I agree, the error may only be the sign, but because there is an error in the sign there may well also be an error in one or more of the coefficient values. |
|
|
I am in contact with someone who works at the College Imperial of London. Actually they have this book so I will keep you up to date as soon as possible. |
|
|
Hello, Sorry for the delay, I finally get two screenshots from the book, Please see attach the coefficients for the liquid nitrogen properties. |
|
|
We can see the minus missing for the liquid viscosity but there is some coefficients for the others properties that do not match those in OpenFoam. Maybe it is because the book I have is the 1982 version. |
|
|
Do you have a preference for which set of coefficients to use? How do the two compare with the NIST data you plotted? |
|
|
I figured out why there is some discrepancies, some properties in the book are not provided with the same units. For instance the density is in mol/m^3 whereas in OpenFOAM it is in kg/m^3. So my conclusion is that the coefficients provided by OpenFOAM are in accordance with the book excepted for the liquid viscosity that I had mentionned before. I just need to look after the coefficients for the heat of vapourization and the one for the surface tension. I have attached some of the properties that are also in accordance with the NIST database Liquid density comparison.png (31,415 bytes) Liquid dynamic viscosity comparison.png (38,594 bytes) Liquid heat capacity comparison.png (30,136 bytes) Liquid thermal conductivity comparison.png (37,752 bytes) |
|
|
Thanks for checking the coefficients Resolved in OpenFOAM-dev by commit f070388e5b9824bb48303ca0569907940e917fec Resolved in OpenFOAM-6 by commit bdc14dcd3de41a6faa3f6a69270d7dccb3f3ac23 |
- Anonymous
