• Description

The Open Recovery File feature is a somewhat unknown feature in the COMSOL Multiphysics®

 software, but it’s useful for anyone running simulations that give multiple solutions. If, for any reason, the software shuts down before the simulation finishes, you can open a recovery file so that you don’t lose your work. Here, we highlight a tutorial video on how to open these files to recover “lost” work as well as go over the strengths and limitations of this feature.

Tutorial Video: How to Open Recovery Files

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Wistia video thumbnail - Tutorial_Opening Saved Recovery Files in {:comsolmph}

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When to Open Recovery Files in COMSOL Multiphysics®

The Open Recovery Files feature is useful for anyone running simulations with multiple parameters, namely:

  • Time-dependent studies
  • Frequency domain studies
  • Auxiliary sweeps
  • Parametric sweeps

While these simulations are running, a recovery file is created after the first solution is found and is then updated after each solved iteration. The recovery file is also updated following any of these three events:

  1. After solving for a specified output time in a time-dependent simulation
  2. After each parametric value in a parametric simulation
  3. After each iteration of a nonlinear stationary simulation

If, at any point in your simulation, COMSOL Multiphysics closes unexpectedly, you can open the recovery file with the saved solutions. You can then continue running the simulation from where it left off.

Screenshot of the Open Recovery File window in COMSOL Multiphysics.
The Open Recovery File window. You can view additional details by clicking on the Show/Hide Details button.

Please note that there are some limitations and subtleties to using this functionality. Currently, the main limitation is that the Parametric Sweep feature can’t be continued — you can rerun the simulation from the beginning or manually run the Parametric Sweep with the remaining values and store the solutions in a new place (not overwriting the first part of the simulation). When the simulation is terminated this way, the data is stored in the Parametric Solution as it should, but the number of solutions from the sweep are not complete. To access the individual parametric solutions, you might need to redirect the datasets to use individual solutions.

To learn more about the ins and outs of this feature, watch the video at the top of this post, where we discuss everything you need to know about opening recovery files. First, we open a model and run a simulation. After waiting until the simulation is nearly done, we force quit the software so that we may reopen it and finish the simulation.