Why Does My COMSOL Model Not Converge at Higher Heat Flux Values?

[martingotu]

I need some help with COMSOL MULTIPHYSICS. I don´t have any experience with FEM analysis. I am solving a non isothermal flow model, and I am varying heat flux that enters in the subdomain through one boundary. I set a value for heat flux, solve it and increase the value to solve the model again setting the current solution as initial value. (analog to use parametric solver but doing it for myself). The question is that when the heat flux reaches a limit value the problem doesn´t converge and I need to solve the problem for a much higher value. I would like to know what is the reason for this and what can I do to get a solution.
If any of you has experience with this software I would like to ask him some doubts.
Thanks for your opinions.
Martin.

 

[Mech_Engineer]

This is a duplicate post of this thread:

https://www.physicsforums.com/showthread.php?t=235253

I basically answer your question:

Technically speaking, there aren't any fundamental reasons you can't raise the flux past a value before the solver doesn't converge, it's really a case-by-case thing based on the problem being solved...

 

[oswaler]

As a scientist with experience in COMSOL, I can offer some advice and insights on your issue. Firstly, it is important to note that non-isothermal flow models can be complex and challenging to solve, especially if you are new to FEM analysis. It is not uncommon for problems to not converge at certain values, and this can be due to a variety of reasons. It could be that your model is not properly defined, or there could be errors in your boundary conditions or initial values. Additionally, the meshing of your model can also affect convergence.

To troubleshoot this issue, I would recommend checking your model setup and making sure all parameters and equations are correctly defined. You can also try refining your mesh to see if that improves convergence. It may also be helpful to consult with the COMSOL community or reach out to their technical support team for further assistance.

In terms of using a parametric solver, it can be a useful tool for solving a range of values, but it is important to note that it should be used with caution. Sometimes, the results from a parametric solver may not be accurate, and it is always best to manually solve for each value to ensure accuracy.

I am happy to answer any specific questions you may have about COMSOL, but I would also recommend reaching out to the COMSOL community for a wider range of experiences and insights. Overall, my advice would be to carefully review your model setup and seek assistance from the COMSOL team or community to troubleshoot the convergence issue.