Hi,
So I am trying to solve a stiff problem using Global ODEs and DAEs. The problem has 32 differential equations and I have inserted all the initial values correctly, however, I keep getting this error.
- Feature: Time-Dependent Solver 1 (sol1/t1) Failed to find consistent initial values. Attempt to evaluate real logarithm of negative number. Last time step is not converged.
The same problem I solved using MATLAB ODE15s solver and with the same set of initial conditions. May I know why can't I solve it using COMSOL.
Thank you very much in advance!
Best regards,
Shannon
This is often due to discretization errors, for high stiff problems (btw, what is the stiffness ratio of yours?) default solver of COMSOL can have some issues. Which solver are you using?
Thank you Luigi. I am using a BDF solver, and I figured the issue. I changed the time-stepping to strict and my issue got solved. Thank you once again
Discretization errors are common in COMSOL, things are better if you use latest release of COMSOL i.e. Nov 2020. Still changing time step would fix this but sometimes things get stuck so its always preferred to use latest version.
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