How should I choose maximum mesh size for thin elements?

I am currently using PDE toolbox to simulate heat transfer of a body consisting many thin layers (magnitude of 1-e6 m). Whenever the amount of thin layers is high, the ODEsolver (ode15s) runs into singularity. By mesh generation I use

generateMesh(thermalmodel, 'Hmax', '0.001')

and when I reduced the Hmax to 0.01 I can simulate more layers. My question is, what is the criteria to best choose my Hmax value?

Also when I change the thickness of my thin layers, say, thicker, the ode solver runs into singularity faster. What factors determine the solution of my ode solver?

Thank you.

Answer 1

[Ravi Kumar]

Your setup seems to be resulting in an ill-conditioned system of equations. Hard to tell without seeing the actual setup. Contact support with reproduction code to see if there are any workaround.