dynamic viscosity for both liquid and vapor

[drunsinn]

request by @fam007e:
add function(s) to calculate viscosity for liquid and vapor state

See also comments in #13

[drunsinn]

@fam007e I created this issue for you. This makes it easier for me to keep track of conversations.

Regarding your request: I can't open most of the links you sent, the require some sort of registration.
The code of the online calculator doesn't contain any calculation functions. It is all done on their server I think.

I you have an Excel Sheet that does the calculation I can probably translate them to python and include them here. To do that it will be necessary to get permission from the original creator first.

It has been a long time since I last used any fluid dynamics stuff myself. I therefore can't guarantee to put much time into researching how to do the calculations you require. On the other hand if you can give me documentation and/or example code it would be much appreciated.

[fam007e]

IAPWSif97_v13----pdf-----MS Excel (with macros but which doesn't seem to work for me.)

[drunsinn]

I checked the documents you sent.
The pdf doesn't contain anything in regards to viscosity as far as I can see. The Excel-File doesn't work for me, it seems it was created with an older version and a modern Excel can't handle it...