Merging multiple time periods of a CFx simulation into one

During the calculation of a CFx simulation, the solver can stop and restart. When this happens, the user can only export one dataset in Case Gold format for each one of the restarts, making it impossible to load the solution in EnSight as a single transient dataset. In this scenario, some operations such as the calculation of the temporal average, or the creation of plots vs. time over all the timeline, will not be possible.

If this is the problem you are facing, then you can use this User Defined Tool presented in this article to concatenate the datasets from the restarts into a single transient Case Gold dataset. The Tool will take care of distinguishing between changing or static connectivity, and will check the sequence of timesteps to create a unique timeset with increasing timesteps.

Shown below is the structure of the directories with the data that you need to have to run this UDT. Note that there is no constraint on the directory names – only on their structure

Transient data





In this example, Data1 will contain the dataset for the first restart, Data2 will contain the dataset for the second restart, and so on.

Download the attached file, un-zip it and place the files into your local UDT directory (which by default is in $CEI_HOME/ensight101/site_preferences/extensions/user_defined/Tools). Open EnSight a first time with the “-no_prefs” option to initially load this tool, and then restart EnSight  normally. Now, you will find the tool among the User Defined Tools.

Double-click on the tool lo launch it. It will pop-up a window asking for the first .case file. Select it and give “Ok”.

The script creates an additional ZData directory under the Transient_Data directory. In this new ZData you will find the new concatenated dataset. Note that the script makes a copy of the original files, doesn’t move/delete them. This means that you can end up using a lot of disk space, if your initial dataset is large.

Please feel free to contact us if you have any question or problem in using this Tool