Vorticity and Gradient python calculator calculation(gives wrong result-Lagrange hexahedron)

python

#1

Vorticity calculated for a smooth vortex function using python calculator as curl(Velocity) gives wrong result using the Legrange Hexahedron element. I tried to plot the same in tecplot using a point data and traingulation, the result looks fas it should on tecplot. I used the same number of levels,range,etc.

As you can see from the figure for paraview plot the vorticity doesn’t vary in the cell for the paraview plot as it should(since its lagrange hexahedron), it gives out a constant value for each cell. I have used lagrange point data and triangulation(which is an approximation) to plot in tecplot and it still gives a better result than paraview. I strongly think it is a major issue in paraview for this cell type.

Process in making the state file:

  1. Create a “Velocity” vector from u,v,w scalar values from data using Calculator Filter
  2. Create “Vorticity”, from velocity vector using curl(Velocity) in Python Calculator Filter
  3. Plot the “Z-Vorticity”

Process to reproduce:
Paraview-Open the data file and then open the state file to perform the vorticity calculation.
Tecplot -Open the layout file with datafile in same folder.

Paraview files:
DataFile- https://drive.google.com/file/d/1AwiXvdbqdPHJI1c7JHwT66SLp5RlauJe/view?usp=sharing
StateFile- finalstate.pvsm (401.2 KB)

Tecplot Files:
Datafile- https://drive.google.com/file/d/13diOAlg0h38Dcyx52q6FRdOas6tOCof-/view?usp=sharing
Layoutfile- vortex.lay (10.2 KB)

Edit: Event the gradient of velocity Calculations seem off(using Gradient of Unstructured data Filter) pics below:
Gradient -0 (dudx)



About high order non-traditional Lagrange Finite Element
#2

Hi all, I was wondering if anyone had similar problems?


#3

Hi all,
Could someone redirect this to anyone who could resolve this issue? I have been trying to find a solution for this for sometime now, but had no response whatsoever.


#4

I also tried with the “Gradient of unstructured data” filter, it gives the correct result. Pic below: