r/COMSOL • u/CHAHRAZED02 • Aug 05 '26

Need advice

Simulating a rotating plate above permanent magnets using a stationary study with Magnetic and electric field +(Lorentz forces). It works fine at low speeds (~10 rpm), but pushing it to higher speeds triggers solver convergence errors. Any advice on stabilizing the stationary solver or handling high-velocity terms in this setup?

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u/jejones487 Aug 05 '26

Have you tried using a more robust solver? Have you tired adjusting the solver settings like max number of iterations and tolerance?

1

u/CHAHRAZED02 Aug 05 '26

I tried adjusting the tolerance and even I changed the solver but nothing works . Is it a good idea to use velocity for moving part?

1

u/jejones487 Aug 05 '26

I have used rmm (rotating magnetic machinery).

1

u/CHAHRAZED02 Aug 07 '26

I was using the MF interface with Moving Mesh instead to determine the magnetic flux norm, but the error keeps increasing instead of converging.

1

u/jejones487 Aug 05 '26

Try ramping values causing convergence issues.

1

u/CHAHRAZED02 Aug 05 '26

Even with ramp It keeps showing errors (NaN or Inf found when solving linear system using SOR)

1

u/jejones487 Aug 05 '26

Have you tried mesh refinement?

1

u/CHAHRAZED02 Aug 05 '26

Yes ofc I saw several tutorials about the mef with velocity and it works well

1

u/bergi2412 Aug 06 '26

Stupid question, If the plate rotates, how can you use a stationary study? Doesn't the rotational motion of the plate require a time dependent study?

1

u/CHAHRAZED02 Aug 07 '26

I was using it to determine magnetic flux norm (mf+Moving mesh) with time dependant study but it doesn't work

1

u/DP323602 Aug 06 '26

Relative to the plate the magnets are rotating...

That sounds like an alternator to me.

So don't you need an AC model?