Stop and resume steady-state calculation

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When I perform computational fluid dynamics (CFD) simulations using ANSYS Fluent, I can stop the computation at any time to inspect the real-time results, and then resume the calculation—even making adjustments to settings and parameters if needed—with the default starting point being the result state at the moment the calculation was stopped. Why is COMSOL unable to achieve this functionality? For example, when solving a steady-state process, clicking "Stop" in the progress bar does not necessarily return the real-time results, nor does it allow the calculation to be continued.


1 Reply Last Post 2026年7月5日 GMT+8 23:56
Robert Koslover Certified Consultant

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Posted: 2 hours ago 2026年7月5日 GMT+8 23:56

If you are doing a time-domain model, you should (in principle) usually be able to stop it (by hitting one of the STOP buttons), inspect intermediate results, and then resume the calculation (by selecting "Continue" under Solve). There are some overhead and memory management operations that are involved when this is done, so the computer may take a while. Do not modify parameters that impact the geometry or mesh between stopping and continuing. Note that there are many circumstances in which stopping and then continuing is a bit tricky and may cause issues. Also, you mentioned a "steady state" process. Are you doing a time-domain model or not? If you are solving for a model that does not involve discrete time steps, then it may not always be possible to stop and inspect solutions along the way. It will depend on the details and type of solver selected (e.g., direct or iterative?) and various other settings. In my experience, very large electromagnetic models do not alway stop/continue gracefully. Again, the success or failure in stopping and then continuing can depend on solver settings and other factors. If you post your .mph file to the forum and identify where/how you are attempting to stop and continue, you may be able to get better advice from others here.

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Scientific Applications & Research Associates (SARA) Inc.
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If you are doing a time-domain model, you should (in principle) usually be able to stop it (by hitting one of the STOP buttons), inspect intermediate results, and then resume the calculation (by selecting "Continue" under Solve). There are some overhead and memory management operations that are involved when this is done, so the computer may take a while. Do not modify parameters that impact the geometry or mesh between stopping and continuing. Note that there are many circumstances in which stopping and then continuing is a bit tricky and may cause issues. Also, you mentioned a "steady state" process. Are you doing a time-domain model or not? If you are solving for a model that does not involve discrete time steps, then it may not always be possible to stop and inspect solutions along the way. It will depend on the details and type of solver selected (e.g., direct or iterative?) and various other settings. In my experience, very large electromagnetic models do not alway stop/continue gracefully. Again, the success or failure in stopping and then continuing can depend on solver settings and other factors. If you post your .mph file to the forum and identify where/how you are attempting to stop and continue, you may be able to get better advice from others here.

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