How to convert own FEM/CFD data file into VTK or other format for PARAVIEW visualization

Greetings. I have struggled to put my data into the “right” VTK format for PARAVIEW visualization (I tried unsuccessfully). “My data” are 2-D FEM/CFD results of a non-isothermal flow problem (velocities and pressure) using 9-node isoparametric quadrilateral elements (but I can use 8-node elements, or the 4-node elements, if needed).

Any help would be appreciated.

Thanks - Harry.

Please explain what are you trying to do in more details, writing a .vtk on disk ? Converting to VTK data structures ?

Please state what is working and what is not working.