Manage numerical method settings and specify additional fields you’d like to calculate beyond the default ones. After any change in the model, update simulation files (ElmerFEM sif files) by clicking Simulation Setup.
Once simulation files are successfully set, you can run the simulation by clicking on Run Simulation.
Postprocessing settings
Choose additional fields to be calculated and included in the results. After simulation, those can be seen and processed using the post-processing tool by clicking on Open in PareView under the Results tab.
Maxwell Stress – The Maxwell Stress tensor is calculated, and the resulting forces are obtained by integrating the tensor over the surfaces of each component part individually. These calculated forces can be found in the results/results.csv file within the case folder.
Save full results – Includes all calculated fields in the final results, even those used for intermediate or temporary computations. This option is generally used for debugging purposes. Enabling this feature will approximately double the size of the result files.
Parallelization settings
Parallel cores – TRAFOLO uses highly parallelized simulation software, Elmer FEM, which uses Message Passing Interface (MPI) for parallelization. Avoid setting this number larger than the number of performance physical cores in your CPU. Modern CPUs have hyper threads and low-power cores. We do not recommend using those.
Recommended – This number represents an estimate of the optimal CPU core count based on model size. Keep in mind that simulation speed does not increase linearly with the number of cores due to the communication overhead between them. Additionally, modern CPUs often manage thermal limits by running at higher clock speeds when fewer cores are in use.
Parallel mesh partitioning method – Occasionally, certain decomposition algorithms may fail efficiently, breaking the mesh and leading to poor convergence. Unless such problems arise, there is no need to change the default value.
Solver settings
Solver preset – A solver setting pattern:
- Fast: Prioritizing computational time over numerical stability.
- Normal: A balance between computational time and stability.
- Slow: Enhances convergence of highly non-linear (e.g. B-H curve) cases but may require a longer simulation time.
- Custom: Allows users to fine-tune the solver settings according to their specific requirements
Nonlinear Relaxation Factor – The software uses a nonlinear solver for electromagnetics such that for nonlinear problems (e.g., involving the B-H curve), the solver incorporates additional outer loop iterations, while the inner loop addresses the linear system. In cases where the nonlinear system encounters convergence issues, it is advisable to reduce this parameter. Note that it might increase simulation time multiple times.
Nonlinear Max Iterations – The solver will terminate when it reaches either the maximum number of iterations or the tolerance threshold.
Min Polynomial Degree – The parameter controls the stability and convergence of the solver, with higher degrees potentially improving convergence but increasing computational complexity.