no clue what the important one was, but start with that, and then one at a time you can put your schemes back to second order

until it breaks

then you know the issue

THANKS! Ill try these!! Again - Really appreciate your time and effort!!

Oh, I also set maxCO to 0.4 instead of 0.9

IVe tried settigns that to 0.1, 0.2 and 0.5 but that didnt solve it alone. If i may ask - why did you remove the underrelaxation of p? ncorrectors -> makes it runs pimpe instead of piso right?

There's the file https://cdn.discordapp.com/attachments/726377664213942323/1410172845295927326/Discord.tgz?ex=68b00d4e&is=68aebbce&hm=7fa4247196b22dfca28bfcd44840ca3ce31f617dcacc5a981dfaca906d97dd9b&

Thanks!

Oh, uh, force of habit, I normally use Pimple, probably right to leave underrelaxation on p 😆

I was speedrunning

But no, nCorrectors > 1 is still piso

nOuterCorrectors is what makes it pimple

Actually wait, if you're using piso you shouldn't have any relaxation factors

Yeah you should either get rid of them, or put ".*Final" 1; in there

though I guess it doesn't hurt to have while troubleshooting, will keep things a little more stable

Anyway, let me know if you're able to figure out your issue 🙂

id look into it!! And ill give you an update!! Also if i manage to get it working with cyclic! 🙂

Im not entirely sure i understand why - is it because they are applied to the outer loop (this case nOuterCorrectors)?

Relaxation factors are a thing with SIMPLE

For piso, if your courant number is <1 you don't need them

Ahh okay - i didnt know that!

But in piso it could be wrong then - then a timestep will be manipulated my relaxtion right? so even thoguh it makes it more stable then its not a true timestep?

Yep

Makes sense thou

some of your variables will be simulated in slow motion

I make sure I always have:

c++
".*Final"    1;

in my relaxation factors, avoids making that mistake

I will - thats a pretty important detail

I think i managed to get it working too. So the changing DDT from backward to euler did it... I used some of the other settings as well afterwards because i believe that is more correct. I still think it is strange that ddt scheme was causing this?

Could try letting it run with Euler, then swap to backward when settled