ddtSchemes
 

Dear all.

In section 4.4.6 the User Guide states that ddtSchemes Euler is implicit. If this is the case, why would I then have to care about max. Co no.? As implicit time schemes are (unconditionally?) stable the chosen time step shouldn't affect the convergence (though affecting the physical validity of obtained results), right?
I now have a case where for a specific time step the sim. crashes after around 10 iterations whereas with a smaller time step everything just runs fine. Any explanations?

Best regards,

Hubert

PS: Please feel free to redirect me to an existing thread if this discussions fits into another thread ...