Update deprecated EXT_ITER option in test configs

[Syphonicc]

EXT_ITER was removed in SU2 v7 and replaced by ITER. These eight configs still used the old name and failed to parse. Values are unchanged; this is a rename only.

All eight verified to run on current develop with a serial build.

Proposed Changes

EXT_ITER was removed in SU2 v7 and replaced by ITER, but eight test configs still used the old name and fail to parse with a "invalid option name" error. This renames the option in each; iteration values are unchanged, so there's no behavioral change.

Files updated:

control_surface/inv_ONERAM6_moving.cfg
control_surface/inv_ONERAM6_setting.cfg
euler/CRM/inv_CRM_JST.cfg
euler/channel/inv_channel.cfg
navierstokes/naca0012/lam_NACA0012.cfg
rans/flatplate/turb_SST_flatplate.cfg
rans/s809/turb_S809.cfg
rans_uq/naca0012/turb_NACA0012_uq.cfg

All eight were run locally on current develop (serial build) and start and converge normally.

Two things I noticed while doing this, not addressed here , happy to open separate issues if useful:

Several other configs have further deprecated options (FROZEN_VISC, REF_LENGTH_MOMENT, GEO_AXIS_STATIONS, SOLUTION_LIN_FILENAME) and some have solver/turbulence-model settings that no longer validate.
The hom_euler test cases reference mesh files that don't appear to exist in either the SU2 or TestCases repos, so those can't be run or verified.

Related Work

None.

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[bigfooted]

While you're at it: I counted 42 instances of EXT_ITER in the Testcases subdirectory.
Are these cases regression-tested? If they have invalid config options they should not be able to run?

[Syphonicc]

While you're at it: I counted 42 instances of EXT_ITER in the Testcases subdirectory. Are these cases regression-tested? If they have invalid config options they should not be able to run?

Right none of them are regression-tested, which is why they've been able to rot. I checked every config containing EXT_ITER against serial_regression.py and parallel_regression.py and none are referenced. As you say, they'd fail immediately in CI otherwise.

I swept all 42 locally (fixing EXT_ITER → ITER and running each with a short iteration cap). Breakdown:

8 run fine with just the rename , those are this PR.

24 are the hom_euler DG cases. They need REF_LENGTH_MOMENT → REF_LENGTH as well, but 21 then fail because the referenced mesh files don't exist in either repo, and 3 are unsteady so EXT_ITER maps to TIME_ITER/INNER_ITER rather than ITER. I left all of these alone since I can't verify them.

The rest need individual fixes: further deprecated options (FROZEN_VISC, GEO_AXIS_STATIONS, SOLUTION_LIN_FILENAME), SOLVER= NAVIER_STOKES with a turbulence model set (should presumably be RANS), SOLVER= FLUID_STRUCTURE_INTERACTION which no longer exists, and a couple of Sutherland's-law validation errors.

Happy to keep going on the fixable ones in follow-up PRs if that's useful I kept this one to the cases I could actually verify run.

[bigfooted]

I think it makes more sense to look at these config files individually, get them working and then add them to the regression test. These might be relatively easy to fix:
euler/CRM/inv_CRM_JST.cfg
euler/channel/inv_channel.cfg
navierstokes/naca0012/lam_NACA0012.cfg
rans/flatplate/turb_SST_flatplate.cfg
rans/s809/turb_S809.cfg

I don't think they test something exotic and you can visually inspect the result to see if it looks reasonable.

I am not sure what the moving/setting onera cases are supposed to test, and for uncertainty quantification a more thorough test is needed to make sure it works as expected.

[Syphonicc]

Updated this to the five cases you suggested, and worked each one properly rather than just doing the rename. Reverted the two ONERAM6 control_surface cases and rans_uq as you suggested.

Case	Converges to	Change
euler/channel/inv_channel	−12.00 @ 6782 ✅	rename only
euler/CRM/inv_CRM_JST	−6.01 @ 778 ✅	rename only
navierstokes/naca0012/lam_NACA0012	−12.00 @ 5824 ✅	CFL 1→3, adaptation on
rans/flatplate/turb_SST_flatplate	−14.46 (plateau, criterion is −15)	adaptation on
rans/s809/turb_S809	−9.02 @ 10k (criterion is −12)	rename only

On the CFL changes: lam_NACA0012 at CFL 1 reached only −8.56 in 10k iterations and would need roughly 60k to meet its −12 criterion; CFL 3 with adaptation converges fully in 5824. turb_SST_flatplate went from −8.26 to −14.46 at 10k iterations just by enabling adaptation. I also tried adaptation on turb_S809 and it made things worse (−7.39 vs −9.02), so I left that one as-is.

While enabling adaptation I hit an error on CFL_ADAPT_PARAM: factor-down and factor-up are swapped in these files (1.5, 0.5 instead of 0.5, 1.5). It's inert wherever CFL_ADAPT= NO, but the same reversed values appear in quite a few other configs. Fixed in the two files where adaptation is now on.

Two cases don't reach their configured CONV_RESIDUAL_MINVAL. turb_SST_flatplate plateaus at −14.46 against −15 (I ran it to 30k; it gained 0.005 between iterations 25k and 30k). turb_S809 is still descending at 10k but slowly. Happy to relax those criteria if you'd prefer, or leave them.

Visual checks below, all coloured by Mach:

• inv_channel — smooth subsonic acceleration over the bump, peak Mach 0.13, no shocks.
• inv_CRM_JST — supersonic pocket on the upper wing reaching Mach 1.3 with a clear spanwise shock, as expected at Mach 0.8395 / AoA 3.06°.
• lam_NACA0012 — thick laminar boundary layer and broad wake, symmetric top/bottom at AoA 0, consistent with Re=5000.
• turb_SST_flatplate — thin turbulent boundary layer growing along the plate at Re=5×10⁶.
• turb_S809 — attached flow with a slight upper-surface bias from the camber, no separation.

All five added to serial_regression.py with test_iter = 25; values verified reproducible locally, though I expect CI will want slightly different ones as before.

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