Calculating diameter change due to FSI

[Aditya Bantwal]

Hi,

I am performing a FSI simulation using svFSI for a simple cylindrical tube.

cylinder.png (54.05 KiB) Viewed 676 times

At a particular location of my geometry, I wish to view the change in diameter of the geometry due to the FSI.

To achieve this in ParaView, this is my workflow:

1. Using the filter "Warp by Vector", I would scale the "displacement" by a factor of 1. (to view the deformed geometry).

warp.png (33.43 KiB) Viewed 676 times

2. At a particular location of this now deformed geometry, create a slice and measure the diameter of the "Warp by Vector".

2.12.png (12.87 KiB) Viewed 676 times

3. Create a slice at the same exact location and measure the diameter for the undeformed geometry.

2.11.png (9.82 KiB) Viewed 676 times

4. Calculate the diameter change by measuring the difference of the diameters.

Please let me know if I am following a reasonable approach, and if not, is there another way?

Thanks in advance for your help.

[Jijo Derick Abraham]

Hi Aditya,
The approach you mentioned looks incompatible to provide accurate values of change in the diameter.
Since svFSI executes calculations on fixed mesh, here is another approach that you could try in the paraview.

• Load your results in the paraview, preferably switch on only the displacement data

• First identify the coordinates of the diametrically opposite points on the periphery of your tube, where you need to find the change in the diameter. Then write them in a csv file

• Then open this csv file in paraview,

• Now you can convert this values to points in the model using Filter->Alphabetical->TableToPoints.
  (Make sure columns in your CSV data are taken into x y z coordinates correctly)

• Now you can use the filter "ResambleWithDataset" to extract the solution values corresponding to these extracted coordinates.
  (while resampling you can use result.vtu as Source Data Arrays and the TabletoPoints as the Destination mesh)

• Further you can save this resampled data into a csv file

• This csv file will contain the accurate values of the displacement of the prescribed points. So adding the displacement with the initial diameter will give you the deformed diameter. Now you can do the further calculations as per your requirements

Hope this is useful
Cheers
Jijo

[Aditya Bantwal]

Hi Jijo, thanks a lot. I will try this and update here.