Plotting and extracting data along a wall (patch) using ParaView

On thing I often need to do is to examine different flow properties along a wall from my model runs in OpenFOAM. A very simple way to do this is to use ParaView.

Step 1. Open up the model run in ParaView as normal. Under the Properties, Mesh Regions, select the region that you are interested in (e.g. the name of the Patch from defined in your mesh model). Advance the model to the time you are interested in.

Step 2. From the Filters menu, select Alphabetical, Extract Block. In the properties for the filter, select the name of the patch you are interested in (make sure that you selected the patch to be active in Step 1, otherwise it will not appear). Click Apply, only the patch you selected should be visible.

Step 3. You can export the data to a csv file at this point. Make sure that the Extract Block object is selected in the Pipeline Browser and under the Menu select File and Save Data. A Save File dialog box will open allowing you to select the location where to save the data as a CSV file.

Step 4. To plot the data, again have the Extract Block selected in the Pipeline Browser and select Plot Data from the Filters/Alphabetical menu. Click Apply from the Object Inspector and the graph should appear. Click into the graph to make it active. Select the Display tab on the Object Inspector and you should see a number of selections. Under Attribute Mode, I typically select Cell Data as opposed to Point Data. Under the Line Series section, all of the flow variables are available to toggle on/off and select the legend.