Post-Processing

Lattice Boltzmann Method LBM: Theory
#1

I know this is not a “purely” LBM topic, but I hope you don’t mind me posting. Throughout my PhD program, I always did my post-processing with Matlab or Tecplot. With Tecplot it is very easy generating, for example, a 2-D contour plot for velocity. However, I always have problems with streamlines. If I am modeling something as simple as a backward step and want to capture the important streamlines, what is the best way? From my memory of Tecplot, I created a “rake” and captured some of the streamlines that way. Can anyone recommend their favorite of post-processing? Thanks.

Nano

#2

I like Paraview quite a lot, especially for 3D data. The interface is very intuitive.

#3

Hi Mr. Latt,

yeah, Paraview is a great tool, 3D streamlines can be easily plotted.

But for those 2D problem, how to plot streamlines from the “.vti” files? Like the example of “Cavity2D”.

thks a lot.

alexlee

#4

hello
I use techplot for this issue.It embraces an icon which allow us to plot streamlines in back and forth direction.it is good enough.
Hamid

#5

thank you, Hamid. By the way, which format of the output file have to be with OpenLB if using Tecplot?

#6

I think Tecplot is able to read the ASCII format, which you get by using the function saveAsciiData (available only in release 0.5). Remember that saveAsciiData saves the data in a linear list, which you need to reshape once in Tecplot (see also this thread). Paraview is really made for processing 3D data, which possibly explains why streamlines can’t be produced for your 2D example.

Another possibility is Matlab, which also computes streamlines of good quality. Again, use ascii format and reshape the data inside Matlab.