search

ibell / coolprop

Deprecated version - go to
https://github.com/CoolProp/CoolProp
MIT License
24 stars 16 forks source link

Thermal conductivity and TTSE #114

Closed jowr closed 10 years ago

jowr commented 10 years ago

Something is wrong with the thermal conductivity calculation when using TTSE. I will try to fix things myself, but if anyone is going to mess around with TTSE due to Sylvain's issue (https://github.com/ibell/coolprop/issues/113), it would be nice if you kept an eye open for this as well. lambda The graphs show thermal conductivity of R134a around the two-phase region at 5 bar. The red line is without TTSE and the blue is with activated TTSE. Do not get surprised, I also activated extended two-phase properties...

ibell commented 10 years ago

Perhaps this could be related to a kSI/SI units conversion problem somehow? Does this behavior exist with other fluids?

On Mon, Jan 27, 2014 at 6:43 PM, Jorrit Wronski notifications@github.comwrote:

Something is wrong with the thermal conductivity calculation when using TTSE. I will try to fix things myself, but if anyone is going to mess around with TTSE due to Sylvain's issue (#113https://github.com/ibell/coolprop/issues/113), it would be nice if you kept an eye open for this as well. [image: lambda]https://f.cloud.github.com/assets/769593/2011390/2d28edc6-877a-11e3-9d19-7c5ce3fe4060.png The graphs show thermal conductivity of R134a around the two-phase region at 5 bar. The red line is without TTSE and the blue is with activated TTSE. Do not get surprised, I also activated extended two-phase properties...

— Reply to this email directly or view it on GitHubhttps://github.com/ibell/coolprop/issues/114 .

jowr commented 10 years ago

Good guess, but there is also something else going on. In attached a plot of thermal conductivity of SES36. The x-axis shows subcooling and superheat at 0.75*p_crit in Kelvin. Note how the graph jumps back to its normal value for higher temperatures. The same can be observed for other fluids as well. I currently make a list of fluids where this occurs. ses36

I made a script that checks the differences and the output for the graph shown above is: 

There were problems with SES36
Relative difference liquid: 0.999000082893
Relative difference vapour: 0.539460016261
Average factor liquid: 1000.08292667
Average factor vapour: 540.476277593
jowr commented 10 years ago

fixed, it was mostly the units...