thank your for the awesome software. Your Software is hands down the best open source solution out there. Hope it will be popular very soon.
I found a Problem while doing a thermal analysis.
When i want to create a Surface which is radiating heat (Load =Radiation) i get the following error:
*ERROR reading *RADIATE: *RADIATE card was selected
but no *PHYSICAL CONSTANTS card encountered
*ERROR reading *RADIATE: *RADIATE card was selected
but no *PHYSICAL CONSTANTS card encountered
*WARNING in calinput: no conductivity
constants were assigned to material WERKZEUG-PROFIL
in a thermo(mechanical) calculation
After some trouble shooting i found out that the Stefan Boltzmann constant is missing in the definition of physical constants.
When i add the following keyword everything works again.
“*Physical constants, Absolute zero=0, Stefan Boltzmann=5.6E-11, Newton gravity=0”
The problem is occuring at least in Prepomax 1.2.0 & 1.1.0
Hi Jakub,
thanks for the information i didn`t know that.
I wonder why you would not set the Boltzmann constant as a default value…
As far as i can see it is a constant which is valid all the time and cannot be changed.
It took me some troubleshooting to find the error and I dont see the point of setting it manually…
Is there anything I am missing ?
The same approach is used in Abaqus, on which CalculiX is based. These programs are primarily unitless (only PrePoMax introduced units) and thus require the definition of physical constants depending on the unit system in a particular model. However, maybe the default values could be added for each of the available unit systems (apart from the unitless one of course) with an option to edit them.
That is true, a default values could be set for a known unit system. But if I remember correctly there were some issues with assigning values to the constants, writing the constants into the inp file and not using a keyword that relies on them. So I thought it better to let the user define them when really needed.
Hello Matej thanks for your feedback !
I cant estimate the effort of prompting a warning message just before submitting the calculation in case Radiation ist activated. If its to much then i guess the user will find this thread here which is also fine
.
I will think about how to inform the user about the missing constants. I do not like to have a program where warning message windows open up all the time.
