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Maximum Number of Newton Iterations Reached
Posted Mar 24, 2023, 3:23 p.m. EDT Fluid & Heat, Porous Media Flow, Physics Interfaces Version 6.1 1 Reply
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Hello everyone,
Apologies for the long message, I am trying to be accurate.
Before delving into the error, some context as to what I am trying to solve. I have completed the 2D heat pipe tutorial from comsol and I am now trying to reproduce the same model but with a 3D geometry. I have slightly modified the geometry but other than that everything has been kept the same.
As you might notice by reading the tutorial/checking the model I have attache below, two studies are being conducted, first with a dry wick and then with a saturated wick. I am able to run without errors the first study (i.e. Study 1 - Dry Wick). The issue lies in the second study (i.e. Study 2 - Saturated Wick), as the solver cannot find values for the "matsw.sw1","1" parameter. To be more precise here is the exact error being displayed:
Error in sweep. - parameters: "matsw.sw1","1" The following feature has encountered a problem: - Feature: Stationary Solver 2 (sol4/s2) Failed to find a solution. Maximum number of Newton Iterations reached. Return solution is not converged. Not all parameter steps returned.
I believe the 'sweep' referes to the fact that I am using the 'material sweep' feature in my studies to switch between the dry and saturated wick. In fact that paramter being addressed has to do with the material. Note that I did not have any of these issues in the 2D Model.
I have tried incrementing the number of iterations from 25 to 50 as well as decreasing the accepted tolerance to but that did not help. I have also tried using non-linear solver but that did not work. I do not believe the mesh is the issue in this case but please do let me know if you think I should refine it further. Please also note that I am conducting study 2 in two steps (i.e. I am using two stationary solvers) One to obtain initial values and then to actually run the simualtion. Hence maybe the inital values are the issue but I do not know how to change that. Another possibility I have thought about is some difference in the way parameters are define for the 3D geometry.
Please do let me know, thank you.