3. Restarting an Analysis

3. Restarting an Analysis#

A mode that performs an analysis using results from a previous run is called restart mode. EMSolution has four primary processes. The restart function lets you rerun the analysis from any of these processes. It lets you continue processing from the point reached in the previous run, and it can reuse the previous results after you change some input data. Restarting can substantially reduce calculation time, especially when you analyze the same geometry while changing source conditions, calculation steps, or output contents. The following describes the processing performed by each process and the cases in which you can restart from it.

PRE_PROCESSING#

  • Processing

    • Read mesh data (nodes and elements).

    • Generate edge elements.

    • Process boundary conditions.

    • Calculate element matrices and volumes.

  • Restart

    • When the mesh discretization is changed.

    • When conductivity or linear magnetic permeability is changed.

    • When the potential formulation in use is changed.

    • When boundary conditions are changed.

MAKE_SYSTEM_MATRICES#

  • Processing

    • Assign unknowns and fixed-boundary variables.

    • Reorder variables.

    • Generate global matrices.

    • Calculate source terms.

  • Restart

    • When switching among magnetostatic, transient magnetic-field, and AC analyses.

    • When current or magnetic-field sources are changed.

    • When sources connected to a power supply are changed.

    • When the time-step interval is changed in transient magnetic-field analysis.

    • When the frequency is changed in AC analysis.

    • When the ICCG acceleration factor is changed.

SOLVE_EQUATION#

  • Processing

    • Solve equations, including matrix preconditioning.

  • Restart

    • When source time variation or initial values are changed.

    • When nonlinear material properties are changed.

    • When you continue steps using the previous results as initial values. In this case, rename the solutions output file from the previous run to old_solutions and use it as an input file.

POST_PROCESSING#

  • Processing

    • Write results.

  • Restart

    • When only result output is required.

Caution

During a restart, output files from the previous run are required. Do not delete generated files unless necessary.

Files written during a restart are overwritten. Preserve files that must be retained, such as output data files, by renaming them.