search

ukaea / PROCESS

PROCESS is a systems code at UKAEA that calculates in a self-consistent manner the parameters of a fusion power plant with a specified performance, ensuring that its operating limits are not violated, and with the option to optimise to a given function of these parameters.
https://ukaea.github.io/PROCESS/
MIT License
36 stars 11 forks source link

`tfcth` calculated inconsistently #3063

Open mkovari opened 9 months ago

mkovari commented 9 months ago

In PROCESS/examples/csv_output_large_tokamak_MFILE.DAT, tcfth is output twice. The first output is wrong - it shows the initial value, not the final value after iteration.

tfcth____________________________________________________ (itvar032)____________________      1.2000E+00

TF_coil_inboard_leg_(m)__________________________________ (tfcth)_______________________      8.6482E-01 ITV

This probably results from incomplete implementation of Issue #515. Note that in this run thkcas is also an iteration variable:

Inboard_leg_case_inboard_"nose"_thickness_(m)____________ (thkcas)______________________      2.2965E-01 ITV

In #515 I recommended that we should remove the option of having tfcth as an iteration variable, but this obviously hasn't been done. I recommended that we should use thkcas and thkwp as iteration variables instead. There are of course many ways to solve this problem, but over-determining tfcth is not one of them.

This is another high priority issue since it could make PROCESS behave erratically and might prevent convergence. @jonmaddock @jmorris-uk @timothy-nunn @ajpearcey

mkovari commented 9 months ago

Tim, If you are going to look at this I would suggest we get some comments from @ajpearcey , @jmorris-uk and @stuartmuldrew.

cjwgriesel commented 9 months ago

I am looking at the magnet dimensions as this is inter related with the cable pack problem.

mkovari commented 9 months ago

Yes, there is a connection between the overall dimensions of the TF coil cross-section (winding pack and case) and the dimensions of the conductor inside it.

However, I suggest trying to keep these topics separate as far as humanly possible.

mkovari commented 3 months ago

I am going to add a check to stop PROCESS if tfcth (inboard TF coil thickness, (centrepost for ST) (m)) is selected as an iteration variable when the TF coil is superconducting (as proposed in Issue #515).