Understanding and using McCryoT

Hi,
I was looking at the releases page and I noticed a software called McCryoT. If I understood correctly, it’s a fork of molflow adapted to radiative thermal calculation, using the same montecarlo computational method underneath (as opposed to ansys and such that use viewfactor).
I find this approach fascinating, since radiative heat exchange and molecular gas dynamics are two similar concepts.
Is the software still usable for such computation? What’s the current status of it, and what would it take to bring it up-to-date with the latest molflow updates? (such as cross section, transient states, etc). Is there documentation and some example studies to understand how ot use it?

Thanks in advance

It was abandoned in 2012 and served only as demonstration.
I think @rkerseva can comment on which paper we demonstrated, the cryopump looked like this:


Surprisingly, it still runs on up to Windows 10.
It would take months of work to port new functions to it.

Thank you! Yeah, I realize that a lot needs to be reimplemented, I was wondering if it was doable by someone with a medium experience in programming if they were motivated enough :sweat_smile:
Do you have any simple examples running on McCryoT? It would be super useful to understand how to use it. I already have experience in molflow, I just need to understand the differences with it

Hello Francesco:
As Marton said, the development of McCryoT has been suspended due to lack of interest on our (CERN’s) part.
Too bad, because in my opinion it would have been a nice alternative to “standard” codes doing the same. Most of them being based on view factors and with GUIs not as user-friendly as ours I think McCryoT was unique.
I validated it vs a similar code developed at KIT Karlsruhe (Christian Day’s group) on a model of the reduced-scale ITER cryopump, with 20 (I think) LHe-cooled panels, and intermediate LN2 heat shield, and th cylindrical shape of the body of the pump with integrated valve on an axially-moving system. If I can find the original article and my reconstruction of it I’ll e-mail it to you, but it is ~10 yrs old stuff on multiply upgraded computers and backups, so I don’t guarantee it. Sorry.

I showed some examples at the 2014 AVS meeting, in Baltimore, were I did a tutorial for Molflow+, see image.

If you already know MolFlow, then the changes are easy to grasp:

  • All facets emit photons as per their temperature (fourth power) and emissivity
  • All facets stick as per their emissivity (=sticking factor)
  • Textures and facets show energy input and output and balance, instead of pressure

I attach a few files that open and run fine in McCryoT.

Cryopump closed/open:

TCPclosed.geo7z (624.7 KB)
TCPopen.geo (5.8 MB)

Three cases simulated from Cristian Day’s paper:

thermal case1.geo7z (280.7 KB)
thermal_case2.geo7z (38.6 KB)
thermal3.geo7z (18.5 KB)

Thank you both so much!